Code
P1446
ALFA ROMEO
P — Powertrain
Additive system fault
Views:
UK: 5
EN: 3
RU: 4
AI status
Completed
Completed
100%
Causes
- Low or empty additive (urea/DPF additive) tank
- Failed dosing pump or injector (stuck, clogged or electrically faulty)
- Faulty additive tank level sensor or pressure/flow sensor
- Damaged, corroded or disconnected wiring/connectors in the additive circuit
- Blocked or leaking additive supply lines or filters
- Control module (additive dosing module/ECU) fault or lost CAN communication
Symptoms
- MIL/emissions warning lamp illuminated and/or dashboard message such as “Additive fault” or “Service SCR/DPF”
- DPF regeneration failures or inability to complete regeneration cycles
- Reduced engine performance or derate in some vehicles
- Increased soot/black smoke or strong ammonia/chemical smell from exhaust
- Repeated additive-related fault codes or persistent lamp after refilling additive
What to check
- Scan for active and stored DTCs and capture freeze-frame and live data related to additive/urea dosing
- Verify additive tank level visually and with the level sensor reading
- Inspect additive tank, lines, filters and connectors for leaks, kinks, cracks or contamination
- Check fuses and relays for additive dosing pump and associated control module
- Back-probe connectors to measure sensor voltages and pump power feed while operating
- Use actuator tests (if available) to run dosing pump and open injector via the scan tool
Signal parameters
- Additive tank level sensor: typical 0–5 V (empty to full) or resistance range per manufacturer
- Dosing pump supply voltage: battery voltage (~11–14 V) when commanded ON
- Dosing pump current draw: normally low (hundreds of mA); high stalled current may occur (amps) — compare to spec
- Injector/dosing valve control: PWM duty cycle or pulse width (0–100%) when commanding dosing events
- Additive pressure/flow sensor: typical 0.5–4.5 V proportional to pressure/flow
- CAN messages: presence/communication with additive dosing module (check module ID and data stream)
Diagnostic algorithm
- Read and record all fault codes (P1446 and any related codes). Capture freeze-frame and live data during fault conditions.
- Check additive level and top up with correct manufacturer-specified additive if low. Re-scan for code persistence.
- Visually inspect additive tank, lines, filters and connections for damage, leaks or contamination. Repair any leaks and replace filters if clogged.
- Inspect electrical: check fuses/relays feeding the dosing pump/module. Back-probe pump and sensor connectors and verify proper supply voltage and ground.
- With a diagnostic tool, command the dosing pump/injector and observe operation and live data (pump current, injector duty). If pump does not run but has proper supply, check control wiring and module.
- Measure level/pressure/flow sensor outputs against expected ranges (0–5 V nominal) and manufacturer specs; replace sensor if out of range.
- Check wiring continuity and for corrosion or high-resistance connections; repair or replace damaged harness sections or connectors.
- Verify CAN/ECU communication: check that the additive dosing module is present and communicating. If module is unresponsive, follow manufacturer procedures for module reset/reprogramming or replacement.
- After repairs, clear codes and perform a regeneration/self-test or a road test per manufacturer procedure to confirm the fault is resolved.
- If fault persists after component checks, consult manufacturer service manual for advanced tests and consider replacing the dosing module or control unit as last resort.
Likely causes
- Low additive level or undetected empty tank
- Dosing pump electrical failure or seized pump
- Clogged dosing injector or additive line
- Corroded connector or broken wire in pump/sensor circuit
- Failed additive level or pressure sensor
Fault status
Status
Additive system fault — check additive tank, dosing pump/injector, sensors and wiring. Service required to restore additive dosing function.
Repair difficulty: Medium
Diagnostic time: 1.5-3.0 hours
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Code
P1446
BMW
P — Powertrain
Diagnostic Module Tank Leakage DM-TL Pump Control Circuit Signal High
Views:
UK: 22
EN: 28
RU: 44
AI status
Completed
Completed
100%
Causes
- Low or empty additive (urea/DPF additive) tank
- Failed dosing pump or injector (stuck, clogged or electrically faulty)
- Faulty additive tank level sensor or pressure/flow sensor
- Damaged, corroded or disconnected wiring/connectors in the additive circuit
- Blocked or leaking additive supply lines or filters
- Control module (additive dosing module/ECU) fault or lost CAN communication
Symptoms
- MIL/emissions warning lamp illuminated and/or dashboard message such as “Additive fault” or “Service SCR/DPF”
- DPF regeneration failures or inability to complete regeneration cycles
- Reduced engine performance or derate in some vehicles
- Increased soot/black smoke or strong ammonia/chemical smell from exhaust
- Repeated additive-related fault codes or persistent lamp after refilling additive
What to check
- Scan for active and stored DTCs and capture freeze-frame and live data related to additive/urea dosing
- Verify additive tank level visually and with the level sensor reading
- Inspect additive tank, lines, filters and connectors for leaks, kinks, cracks or contamination
- Check fuses and relays for additive dosing pump and associated control module
- Back-probe connectors to measure sensor voltages and pump power feed while operating
- Use actuator tests (if available) to run dosing pump and open injector via the scan tool
Signal parameters
- Additive tank level sensor: typical 0–5 V (empty to full) or resistance range per manufacturer
- Dosing pump supply voltage: battery voltage (~11–14 V) when commanded ON
- Dosing pump current draw: normally low (hundreds of mA); high stalled current may occur (amps) — compare to spec
- Injector/dosing valve control: PWM duty cycle or pulse width (0–100%) when commanding dosing events
- Additive pressure/flow sensor: typical 0.5–4.5 V proportional to pressure/flow
- CAN messages: presence/communication with additive dosing module (check module ID and data stream)
Diagnostic algorithm
- Read and record all fault codes (P1446 and any related codes). Capture freeze-frame and live data during fault conditions.
- Check additive level and top up with correct manufacturer-specified additive if low. Re-scan for code persistence.
- Visually inspect additive tank, lines, filters and connections for damage, leaks or contamination. Repair any leaks and replace filters if clogged.
- Inspect electrical: check fuses/relays feeding the dosing pump/module. Back-probe pump and sensor connectors and verify proper supply voltage and ground.
- With a diagnostic tool, command the dosing pump/injector and observe operation and live data (pump current, injector duty). If pump does not run but has proper supply, check control wiring and module.
- Measure level/pressure/flow sensor outputs against expected ranges (0–5 V nominal) and manufacturer specs; replace sensor if out of range.
- Check wiring continuity and for corrosion or high-resistance connections; repair or replace damaged harness sections or connectors.
- Verify CAN/ECU communication: check that the additive dosing module is present and communicating. If module is unresponsive, follow manufacturer procedures for module reset/reprogramming or replacement.
- After repairs, clear codes and perform a regeneration/self-test or a road test per manufacturer procedure to confirm the fault is resolved.
- If fault persists after component checks, consult manufacturer service manual for advanced tests and consider replacing the dosing module or control unit as last resort.
Likely causes
- Low additive level or undetected empty tank
- Dosing pump electrical failure or seized pump
- Clogged dosing injector or additive line
- Corroded connector or broken wire in pump/sensor circuit
- Failed additive level or pressure sensor
Fault status
Status
Additive system fault — check additive tank, dosing pump/injector, sensors and wiring. Service required to restore additive dosing function.
Repair difficulty: Medium
Diagnostic time: 1.5-3.0 hours
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Code
P1446
FIAT
P — Powertrain
Additive system fault
Views:
UK: 5
EN: 1
RU: 4
AI status
Completed
Completed
100%
Causes
- Low or empty additive (urea/DPF additive) tank
- Failed dosing pump or injector (stuck, clogged or electrically faulty)
- Faulty additive tank level sensor or pressure/flow sensor
- Damaged, corroded or disconnected wiring/connectors in the additive circuit
- Blocked or leaking additive supply lines or filters
- Control module (additive dosing module/ECU) fault or lost CAN communication
Symptoms
- MIL/emissions warning lamp illuminated and/or dashboard message such as “Additive fault” or “Service SCR/DPF”
- DPF regeneration failures or inability to complete regeneration cycles
- Reduced engine performance or derate in some vehicles
- Increased soot/black smoke or strong ammonia/chemical smell from exhaust
- Repeated additive-related fault codes or persistent lamp after refilling additive
What to check
- Scan for active and stored DTCs and capture freeze-frame and live data related to additive/urea dosing
- Verify additive tank level visually and with the level sensor reading
- Inspect additive tank, lines, filters and connectors for leaks, kinks, cracks or contamination
- Check fuses and relays for additive dosing pump and associated control module
- Back-probe connectors to measure sensor voltages and pump power feed while operating
- Use actuator tests (if available) to run dosing pump and open injector via the scan tool
Signal parameters
- Additive tank level sensor: typical 0–5 V (empty to full) or resistance range per manufacturer
- Dosing pump supply voltage: battery voltage (~11–14 V) when commanded ON
- Dosing pump current draw: normally low (hundreds of mA); high stalled current may occur (amps) — compare to spec
- Injector/dosing valve control: PWM duty cycle or pulse width (0–100%) when commanding dosing events
- Additive pressure/flow sensor: typical 0.5–4.5 V proportional to pressure/flow
- CAN messages: presence/communication with additive dosing module (check module ID and data stream)
Diagnostic algorithm
- Read and record all fault codes (P1446 and any related codes). Capture freeze-frame and live data during fault conditions.
- Check additive level and top up with correct manufacturer-specified additive if low. Re-scan for code persistence.
- Visually inspect additive tank, lines, filters and connections for damage, leaks or contamination. Repair any leaks and replace filters if clogged.
- Inspect electrical: check fuses/relays feeding the dosing pump/module. Back-probe pump and sensor connectors and verify proper supply voltage and ground.
- With a diagnostic tool, command the dosing pump/injector and observe operation and live data (pump current, injector duty). If pump does not run but has proper supply, check control wiring and module.
- Measure level/pressure/flow sensor outputs against expected ranges (0–5 V nominal) and manufacturer specs; replace sensor if out of range.
- Check wiring continuity and for corrosion or high-resistance connections; repair or replace damaged harness sections or connectors.
- Verify CAN/ECU communication: check that the additive dosing module is present and communicating. If module is unresponsive, follow manufacturer procedures for module reset/reprogramming or replacement.
- After repairs, clear codes and perform a regeneration/self-test or a road test per manufacturer procedure to confirm the fault is resolved.
- If fault persists after component checks, consult manufacturer service manual for advanced tests and consider replacing the dosing module or control unit as last resort.
Likely causes
- Low additive level or undetected empty tank
- Dosing pump electrical failure or seized pump
- Clogged dosing injector or additive line
- Corroded connector or broken wire in pump/sensor circuit
- Failed additive level or pressure sensor
Fault status
Status
Additive system fault — check additive tank, dosing pump/injector, sensors and wiring. Service required to restore additive dosing function.
Repair difficulty: Medium
Diagnostic time: 1.5-3.0 hours
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Code
P1446
MAZDA
P — Powertrain
Evaporative Vacuum Solenoid Circuit
Views:
UK: 21
EN: 20
RU: 31
AI status
Completed
Completed
100%
Causes
- Low or empty additive (urea/DPF additive) tank
- Failed dosing pump or injector (stuck, clogged or electrically faulty)
- Faulty additive tank level sensor or pressure/flow sensor
- Damaged, corroded or disconnected wiring/connectors in the additive circuit
- Blocked or leaking additive supply lines or filters
- Control module (additive dosing module/ECU) fault or lost CAN communication
Symptoms
- MIL/emissions warning lamp illuminated and/or dashboard message such as “Additive fault” or “Service SCR/DPF”
- DPF regeneration failures or inability to complete regeneration cycles
- Reduced engine performance or derate in some vehicles
- Increased soot/black smoke or strong ammonia/chemical smell from exhaust
- Repeated additive-related fault codes or persistent lamp after refilling additive
What to check
- Scan for active and stored DTCs and capture freeze-frame and live data related to additive/urea dosing
- Verify additive tank level visually and with the level sensor reading
- Inspect additive tank, lines, filters and connectors for leaks, kinks, cracks or contamination
- Check fuses and relays for additive dosing pump and associated control module
- Back-probe connectors to measure sensor voltages and pump power feed while operating
- Use actuator tests (if available) to run dosing pump and open injector via the scan tool
Signal parameters
- Additive tank level sensor: typical 0–5 V (empty to full) or resistance range per manufacturer
- Dosing pump supply voltage: battery voltage (~11–14 V) when commanded ON
- Dosing pump current draw: normally low (hundreds of mA); high stalled current may occur (amps) — compare to spec
- Injector/dosing valve control: PWM duty cycle or pulse width (0–100%) when commanding dosing events
- Additive pressure/flow sensor: typical 0.5–4.5 V proportional to pressure/flow
- CAN messages: presence/communication with additive dosing module (check module ID and data stream)
Diagnostic algorithm
- Read and record all fault codes (P1446 and any related codes). Capture freeze-frame and live data during fault conditions.
- Check additive level and top up with correct manufacturer-specified additive if low. Re-scan for code persistence.
- Visually inspect additive tank, lines, filters and connections for damage, leaks or contamination. Repair any leaks and replace filters if clogged.
- Inspect electrical: check fuses/relays feeding the dosing pump/module. Back-probe pump and sensor connectors and verify proper supply voltage and ground.
- With a diagnostic tool, command the dosing pump/injector and observe operation and live data (pump current, injector duty). If pump does not run but has proper supply, check control wiring and module.
- Measure level/pressure/flow sensor outputs against expected ranges (0–5 V nominal) and manufacturer specs; replace sensor if out of range.
- Check wiring continuity and for corrosion or high-resistance connections; repair or replace damaged harness sections or connectors.
- Verify CAN/ECU communication: check that the additive dosing module is present and communicating. If module is unresponsive, follow manufacturer procedures for module reset/reprogramming or replacement.
- After repairs, clear codes and perform a regeneration/self-test or a road test per manufacturer procedure to confirm the fault is resolved.
- If fault persists after component checks, consult manufacturer service manual for advanced tests and consider replacing the dosing module or control unit as last resort.
Likely causes
- Low additive level or undetected empty tank
- Dosing pump electrical failure or seized pump
- Clogged dosing injector or additive line
- Corroded connector or broken wire in pump/sensor circuit
- Failed additive level or pressure sensor
Fault status
Status
Additive system fault — check additive tank, dosing pump/injector, sensors and wiring. Service required to restore additive dosing function.
Repair difficulty: Medium
Diagnostic time: 1.5-3.0 hours
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Code
P1446
NISSAN
P — Powertrain
EVAP Canister Vent Control Valve Closed
Views:
UK: 24
EN: 25
RU: 33
AI status
Completed
Completed
100%
Causes
- Low or empty additive (urea/DPF additive) tank
- Failed dosing pump or injector (stuck, clogged or electrically faulty)
- Faulty additive tank level sensor or pressure/flow sensor
- Damaged, corroded or disconnected wiring/connectors in the additive circuit
- Blocked or leaking additive supply lines or filters
- Control module (additive dosing module/ECU) fault or lost CAN communication
Symptoms
- MIL/emissions warning lamp illuminated and/or dashboard message such as “Additive fault” or “Service SCR/DPF”
- DPF regeneration failures or inability to complete regeneration cycles
- Reduced engine performance or derate in some vehicles
- Increased soot/black smoke or strong ammonia/chemical smell from exhaust
- Repeated additive-related fault codes or persistent lamp after refilling additive
What to check
- Scan for active and stored DTCs and capture freeze-frame and live data related to additive/urea dosing
- Verify additive tank level visually and with the level sensor reading
- Inspect additive tank, lines, filters and connectors for leaks, kinks, cracks or contamination
- Check fuses and relays for additive dosing pump and associated control module
- Back-probe connectors to measure sensor voltages and pump power feed while operating
- Use actuator tests (if available) to run dosing pump and open injector via the scan tool
Signal parameters
- Additive tank level sensor: typical 0–5 V (empty to full) or resistance range per manufacturer
- Dosing pump supply voltage: battery voltage (~11–14 V) when commanded ON
- Dosing pump current draw: normally low (hundreds of mA); high stalled current may occur (amps) — compare to spec
- Injector/dosing valve control: PWM duty cycle or pulse width (0–100%) when commanding dosing events
- Additive pressure/flow sensor: typical 0.5–4.5 V proportional to pressure/flow
- CAN messages: presence/communication with additive dosing module (check module ID and data stream)
Diagnostic algorithm
- Read and record all fault codes (P1446 and any related codes). Capture freeze-frame and live data during fault conditions.
- Check additive level and top up with correct manufacturer-specified additive if low. Re-scan for code persistence.
- Visually inspect additive tank, lines, filters and connections for damage, leaks or contamination. Repair any leaks and replace filters if clogged.
- Inspect electrical: check fuses/relays feeding the dosing pump/module. Back-probe pump and sensor connectors and verify proper supply voltage and ground.
- With a diagnostic tool, command the dosing pump/injector and observe operation and live data (pump current, injector duty). If pump does not run but has proper supply, check control wiring and module.
- Measure level/pressure/flow sensor outputs against expected ranges (0–5 V nominal) and manufacturer specs; replace sensor if out of range.
- Check wiring continuity and for corrosion or high-resistance connections; repair or replace damaged harness sections or connectors.
- Verify CAN/ECU communication: check that the additive dosing module is present and communicating. If module is unresponsive, follow manufacturer procedures for module reset/reprogramming or replacement.
- After repairs, clear codes and perform a regeneration/self-test or a road test per manufacturer procedure to confirm the fault is resolved.
- If fault persists after component checks, consult manufacturer service manual for advanced tests and consider replacing the dosing module or control unit as last resort.
Likely causes
- Low additive level or undetected empty tank
- Dosing pump electrical failure or seized pump
- Clogged dosing injector or additive line
- Corroded connector or broken wire in pump/sensor circuit
- Failed additive level or pressure sensor
Fault status
Status
Additive system fault — check additive tank, dosing pump/injector, sensors and wiring. Service required to restore additive dosing function.
Repair difficulty: Medium
Diagnostic time: 1.5-3.0 hours
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Code
P1446
Other
P — Powertrain
Evaporative Vac Solenoid Circuit Malfunction
Views:
UK: 20
EN: 20
RU: 32
AI status
Completed
Completed
100%
Causes
- Low or empty additive (urea/DPF additive) tank
- Failed dosing pump or injector (stuck, clogged or electrically faulty)
- Faulty additive tank level sensor or pressure/flow sensor
- Damaged, corroded or disconnected wiring/connectors in the additive circuit
- Blocked or leaking additive supply lines or filters
- Control module (additive dosing module/ECU) fault or lost CAN communication
Symptoms
- MIL/emissions warning lamp illuminated and/or dashboard message such as “Additive fault” or “Service SCR/DPF”
- DPF regeneration failures or inability to complete regeneration cycles
- Reduced engine performance or derate in some vehicles
- Increased soot/black smoke or strong ammonia/chemical smell from exhaust
- Repeated additive-related fault codes or persistent lamp after refilling additive
What to check
- Scan for active and stored DTCs and capture freeze-frame and live data related to additive/urea dosing
- Verify additive tank level visually and with the level sensor reading
- Inspect additive tank, lines, filters and connectors for leaks, kinks, cracks or contamination
- Check fuses and relays for additive dosing pump and associated control module
- Back-probe connectors to measure sensor voltages and pump power feed while operating
- Use actuator tests (if available) to run dosing pump and open injector via the scan tool
Signal parameters
- Additive tank level sensor: typical 0–5 V (empty to full) or resistance range per manufacturer
- Dosing pump supply voltage: battery voltage (~11–14 V) when commanded ON
- Dosing pump current draw: normally low (hundreds of mA); high stalled current may occur (amps) — compare to spec
- Injector/dosing valve control: PWM duty cycle or pulse width (0–100%) when commanding dosing events
- Additive pressure/flow sensor: typical 0.5–4.5 V proportional to pressure/flow
- CAN messages: presence/communication with additive dosing module (check module ID and data stream)
Diagnostic algorithm
- Read and record all fault codes (P1446 and any related codes). Capture freeze-frame and live data during fault conditions.
- Check additive level and top up with correct manufacturer-specified additive if low. Re-scan for code persistence.
- Visually inspect additive tank, lines, filters and connections for damage, leaks or contamination. Repair any leaks and replace filters if clogged.
- Inspect electrical: check fuses/relays feeding the dosing pump/module. Back-probe pump and sensor connectors and verify proper supply voltage and ground.
- With a diagnostic tool, command the dosing pump/injector and observe operation and live data (pump current, injector duty). If pump does not run but has proper supply, check control wiring and module.
- Measure level/pressure/flow sensor outputs against expected ranges (0–5 V nominal) and manufacturer specs; replace sensor if out of range.
- Check wiring continuity and for corrosion or high-resistance connections; repair or replace damaged harness sections or connectors.
- Verify CAN/ECU communication: check that the additive dosing module is present and communicating. If module is unresponsive, follow manufacturer procedures for module reset/reprogramming or replacement.
- After repairs, clear codes and perform a regeneration/self-test or a road test per manufacturer procedure to confirm the fault is resolved.
- If fault persists after component checks, consult manufacturer service manual for advanced tests and consider replacing the dosing module or control unit as last resort.
Likely causes
- Low additive level or undetected empty tank
- Dosing pump electrical failure or seized pump
- Clogged dosing injector or additive line
- Corroded connector or broken wire in pump/sensor circuit
- Failed additive level or pressure sensor
Fault status
Status
Additive system fault — check additive tank, dosing pump/injector, sensors and wiring. Service required to restore additive dosing function.
Repair difficulty: Medium
Diagnostic time: 1.5-3.0 hours
Similar codes
Workshop Manuals
Available brands with manuals
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LAND ROVER 1
Land Rover Defender Workshop Manual 1999-2002 MY
Workshop ManualYour experience will help others
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Code
P1446
VOLKSWAGEN
P — Powertrain
Catalyst Temperature Circuit Short To Ground
Views:
UK: 21
EN: 31
RU: 40
AI status
Completed
Completed
100%
Causes
- Low or empty additive (urea/DPF additive) tank
- Failed dosing pump or injector (stuck, clogged or electrically faulty)
- Faulty additive tank level sensor or pressure/flow sensor
- Damaged, corroded or disconnected wiring/connectors in the additive circuit
- Blocked or leaking additive supply lines or filters
- Control module (additive dosing module/ECU) fault or lost CAN communication
Symptoms
- MIL/emissions warning lamp illuminated and/or dashboard message such as “Additive fault” or “Service SCR/DPF”
- DPF regeneration failures or inability to complete regeneration cycles
- Reduced engine performance or derate in some vehicles
- Increased soot/black smoke or strong ammonia/chemical smell from exhaust
- Repeated additive-related fault codes or persistent lamp after refilling additive
What to check
- Scan for active and stored DTCs and capture freeze-frame and live data related to additive/urea dosing
- Verify additive tank level visually and with the level sensor reading
- Inspect additive tank, lines, filters and connectors for leaks, kinks, cracks or contamination
- Check fuses and relays for additive dosing pump and associated control module
- Back-probe connectors to measure sensor voltages and pump power feed while operating
- Use actuator tests (if available) to run dosing pump and open injector via the scan tool
Signal parameters
- Additive tank level sensor: typical 0–5 V (empty to full) or resistance range per manufacturer
- Dosing pump supply voltage: battery voltage (~11–14 V) when commanded ON
- Dosing pump current draw: normally low (hundreds of mA); high stalled current may occur (amps) — compare to spec
- Injector/dosing valve control: PWM duty cycle or pulse width (0–100%) when commanding dosing events
- Additive pressure/flow sensor: typical 0.5–4.5 V proportional to pressure/flow
- CAN messages: presence/communication with additive dosing module (check module ID and data stream)
Diagnostic algorithm
- Read and record all fault codes (P1446 and any related codes). Capture freeze-frame and live data during fault conditions.
- Check additive level and top up with correct manufacturer-specified additive if low. Re-scan for code persistence.
- Visually inspect additive tank, lines, filters and connections for damage, leaks or contamination. Repair any leaks and replace filters if clogged.
- Inspect electrical: check fuses/relays feeding the dosing pump/module. Back-probe pump and sensor connectors and verify proper supply voltage and ground.
- With a diagnostic tool, command the dosing pump/injector and observe operation and live data (pump current, injector duty). If pump does not run but has proper supply, check control wiring and module.
- Measure level/pressure/flow sensor outputs against expected ranges (0–5 V nominal) and manufacturer specs; replace sensor if out of range.
- Check wiring continuity and for corrosion or high-resistance connections; repair or replace damaged harness sections or connectors.
- Verify CAN/ECU communication: check that the additive dosing module is present and communicating. If module is unresponsive, follow manufacturer procedures for module reset/reprogramming or replacement.
- After repairs, clear codes and perform a regeneration/self-test or a road test per manufacturer procedure to confirm the fault is resolved.
- If fault persists after component checks, consult manufacturer service manual for advanced tests and consider replacing the dosing module or control unit as last resort.
Likely causes
- Low additive level or undetected empty tank
- Dosing pump electrical failure or seized pump
- Clogged dosing injector or additive line
- Corroded connector or broken wire in pump/sensor circuit
- Failed additive level or pressure sensor
Fault status
Status
Additive system fault — check additive tank, dosing pump/injector, sensors and wiring. Service required to restore additive dosing function.
Repair difficulty: Medium
Diagnostic time: 1.5-3.0 hours
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