Code
P0135
AUDI
P — Powertrain
Defective Oxygen Sensor/Air Fuel Ratio Sensor, defective Oxygen Sensor/Air Fuel Ratio Sensor Heater Circuit, Exhaust System Leak, Intake Air System leak, Low Fuel Pressure, Defective Engine Coolant Temperature Sensor, Defective sensor wiring and or circuit problem, PCM software needs to be updated, Defective PCM
Views:
UK: 34
EN: 37
RU: 107
AI status
Completed
Completed
100%
Causes
- Failed O2 sensor heater element
- Open or shorted heater circuit wiring (power or ground)
- Blown fuse or faulty relay supplying heater circuit
- Corroded/poor connector or pin contact at sensor or harness
- PCM driver fault or internal short
- Aftermarket or incorrect sensor installed
Symptoms
- Check Engine Light (MIL) illuminated with P0135 stored
- Heater-related readiness monitor incomplete or in fault
- Long cold start enrichment / poor emissions until engine warms up
- Lower fuel economy or rough idle until sensor warms
- Elevated tailpipe emissions (failed emissions test)
- Possible intermittent MIL if wiring or connector is intermittent
What to check
- Retrieve freeze frame and live data with a diagnostic scan tool (confirm Bank 1 Sensor 1 identification)
- Verify vehicle-specific code is P0135 (heater circuit) and check readiness status
- Visually inspect sensor, wiring, and connector for damage, corrosion, melted insulation, or exhaust soot
- Check fuses and relays related to O2 sensor heaters
- Backprobe heater power and ground pins with ignition ON (engine off) to confirm supply voltage and control ground per factory wiring diagrams
- Measure heater resistance at sensor with connector disconnected and compare to specification
Signal parameters
- Heater resistance (cold): typically 2–20 ohms depending on sensor; consult Audi spec
- Heater supply voltage: battery voltage (approx. 12 V) with ignition ON (engine off)
- Heater control: PCM provides ground switching or a fused supply feed — verify switching behavior with scope or DVOM
- O2 sensor voltage (post-heater warmup): switching ~0.1–0.9 V in rich/lean cycles for narrowband sensors
- Heater current draw: expected few hundred mA; abnormally high indicates short, open indicates open circuit
Diagnostic algorithm
- Connect a scan tool, confirm P0135 and identify Bank 1 Sensor 1. Record freeze frame and readiness status.
- Perform a visual inspection of the sensor, connector, and wiring harness for damage, corrosion, rodent chew, or heat damage.
- With ignition OFF, disconnect sensor connector. Measure heater element resistance across heater pins; compare to Audi spec. If within spec, proceed; if open/infinite or shorted, replace sensor.
- With connector disconnected and ignition ON (engine off), measure heater supply voltage at harness pin. If no supply, check related fuses/relays and wiring back to power source.
- With connector disconnected, backprobe heater ground/control pin and monitor while cranking or with engine running if required per OEM procedure; verify PCM provides ground switching (or supply) as specified.
- If supply and control are present but heater resistance out of range, replace sensor. If heater resistance is correct but no switching/ground from PCM, inspect wiring for opens/shorts and repair. Check for shorts to battery or ground.
- If wiring and connectors are good but PCM does not command the heater, check for relevant fuse/relay and then consider PCM output testing or software update per Audi service info; contact dealer for confirmed software/TSB.
- After repair or replacement, clear codes, perform drive cycle or forced readiness, and confirm code does not return. Verify proper sensor switching and heater operation with live data.
- If intermittent, wiggle-test harness, inspect for chafing, and consider securing wiring; use smoke test to detect exhaust leaks that could influence sensor behavior.
Likely causes
- Failed oxygen sensor heater (most common)
- Damaged sensor connector (corrosion or water intrusion)
- Broken or shorted heater supply/ground wire between sensor and PCM
- Blown fuse or faulty fuse link for heater circuit
- PCM heater driver failure (less common)
Fault status
Status
P0135 — Oxygen Sensor (Bank 1, Sensor 1) Heater Circuit Malfunction. Heater circuit failed to operate within expected parameters; sensor may not reach operating temperature.
Repair difficulty: Medium
Diagnostic time: 0.5 - 2.0 hours
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Code
P0135
Generic
P — Powertrain
O2 Sensor Heater Circuit Bank 1 Sensor 1
Views:
UK: 35
EN: 37
RU: 110
AI status
Completed
Completed
100%
Causes
- Failed O2 sensor heater element
- Open or shorted heater circuit wiring (power or ground)
- Blown fuse or faulty relay supplying heater circuit
- Corroded/poor connector or pin contact at sensor or harness
- PCM driver fault or internal short
- Aftermarket or incorrect sensor installed
Symptoms
- Check Engine Light (MIL) illuminated with P0135 stored
- Heater-related readiness monitor incomplete or in fault
- Long cold start enrichment / poor emissions until engine warms up
- Lower fuel economy or rough idle until sensor warms
- Elevated tailpipe emissions (failed emissions test)
- Possible intermittent MIL if wiring or connector is intermittent
What to check
- Retrieve freeze frame and live data with a diagnostic scan tool (confirm Bank 1 Sensor 1 identification)
- Verify vehicle-specific code is P0135 (heater circuit) and check readiness status
- Visually inspect sensor, wiring, and connector for damage, corrosion, melted insulation, or exhaust soot
- Check fuses and relays related to O2 sensor heaters
- Backprobe heater power and ground pins with ignition ON (engine off) to confirm supply voltage and control ground per factory wiring diagrams
- Measure heater resistance at sensor with connector disconnected and compare to specification
Signal parameters
- Heater resistance (cold): typically 2–20 ohms depending on sensor; consult Audi spec
- Heater supply voltage: battery voltage (approx. 12 V) with ignition ON (engine off)
- Heater control: PCM provides ground switching or a fused supply feed — verify switching behavior with scope or DVOM
- O2 sensor voltage (post-heater warmup): switching ~0.1–0.9 V in rich/lean cycles for narrowband sensors
- Heater current draw: expected few hundred mA; abnormally high indicates short, open indicates open circuit
Diagnostic algorithm
- Connect a scan tool, confirm P0135 and identify Bank 1 Sensor 1. Record freeze frame and readiness status.
- Perform a visual inspection of the sensor, connector, and wiring harness for damage, corrosion, rodent chew, or heat damage.
- With ignition OFF, disconnect sensor connector. Measure heater element resistance across heater pins; compare to Audi spec. If within spec, proceed; if open/infinite or shorted, replace sensor.
- With connector disconnected and ignition ON (engine off), measure heater supply voltage at harness pin. If no supply, check related fuses/relays and wiring back to power source.
- With connector disconnected, backprobe heater ground/control pin and monitor while cranking or with engine running if required per OEM procedure; verify PCM provides ground switching (or supply) as specified.
- If supply and control are present but heater resistance out of range, replace sensor. If heater resistance is correct but no switching/ground from PCM, inspect wiring for opens/shorts and repair. Check for shorts to battery or ground.
- If wiring and connectors are good but PCM does not command the heater, check for relevant fuse/relay and then consider PCM output testing or software update per Audi service info; contact dealer for confirmed software/TSB.
- After repair or replacement, clear codes, perform drive cycle or forced readiness, and confirm code does not return. Verify proper sensor switching and heater operation with live data.
- If intermittent, wiggle-test harness, inspect for chafing, and consider securing wiring; use smoke test to detect exhaust leaks that could influence sensor behavior.
Likely causes
- Failed oxygen sensor heater (most common)
- Damaged sensor connector (corrosion or water intrusion)
- Broken or shorted heater supply/ground wire between sensor and PCM
- Blown fuse or faulty fuse link for heater circuit
- PCM heater driver failure (less common)
Fault status
Status
P0135 — Oxygen Sensor (Bank 1, Sensor 1) Heater Circuit Malfunction. Heater circuit failed to operate within expected parameters; sensor may not reach operating temperature.
Repair difficulty: Medium
Diagnostic time: 0.5 - 2.0 hours
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Workshop Manuals
Available brands with manuals
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Code
P0135
GWM
P — Powertrain
- Heated oxygen sensor circuit fault (bank 1, sensor 1)
Views:
UK: 3
EN: 6
RU: 19
AI status
Completed
Completed
100%
Causes
- Failed O2 sensor heater element
- Open or shorted heater circuit wiring (power or ground)
- Blown fuse or faulty relay supplying heater circuit
- Corroded/poor connector or pin contact at sensor or harness
- PCM driver fault or internal short
- Aftermarket or incorrect sensor installed
Symptoms
- Check Engine Light (MIL) illuminated with P0135 stored
- Heater-related readiness monitor incomplete or in fault
- Long cold start enrichment / poor emissions until engine warms up
- Lower fuel economy or rough idle until sensor warms
- Elevated tailpipe emissions (failed emissions test)
- Possible intermittent MIL if wiring or connector is intermittent
What to check
- Retrieve freeze frame and live data with a diagnostic scan tool (confirm Bank 1 Sensor 1 identification)
- Verify vehicle-specific code is P0135 (heater circuit) and check readiness status
- Visually inspect sensor, wiring, and connector for damage, corrosion, melted insulation, or exhaust soot
- Check fuses and relays related to O2 sensor heaters
- Backprobe heater power and ground pins with ignition ON (engine off) to confirm supply voltage and control ground per factory wiring diagrams
- Measure heater resistance at sensor with connector disconnected and compare to specification
Signal parameters
- Heater resistance (cold): typically 2–20 ohms depending on sensor; consult Audi spec
- Heater supply voltage: battery voltage (approx. 12 V) with ignition ON (engine off)
- Heater control: PCM provides ground switching or a fused supply feed — verify switching behavior with scope or DVOM
- O2 sensor voltage (post-heater warmup): switching ~0.1–0.9 V in rich/lean cycles for narrowband sensors
- Heater current draw: expected few hundred mA; abnormally high indicates short, open indicates open circuit
Diagnostic algorithm
- Connect a scan tool, confirm P0135 and identify Bank 1 Sensor 1. Record freeze frame and readiness status.
- Perform a visual inspection of the sensor, connector, and wiring harness for damage, corrosion, rodent chew, or heat damage.
- With ignition OFF, disconnect sensor connector. Measure heater element resistance across heater pins; compare to Audi spec. If within spec, proceed; if open/infinite or shorted, replace sensor.
- With connector disconnected and ignition ON (engine off), measure heater supply voltage at harness pin. If no supply, check related fuses/relays and wiring back to power source.
- With connector disconnected, backprobe heater ground/control pin and monitor while cranking or with engine running if required per OEM procedure; verify PCM provides ground switching (or supply) as specified.
- If supply and control are present but heater resistance out of range, replace sensor. If heater resistance is correct but no switching/ground from PCM, inspect wiring for opens/shorts and repair. Check for shorts to battery or ground.
- If wiring and connectors are good but PCM does not command the heater, check for relevant fuse/relay and then consider PCM output testing or software update per Audi service info; contact dealer for confirmed software/TSB.
- After repair or replacement, clear codes, perform drive cycle or forced readiness, and confirm code does not return. Verify proper sensor switching and heater operation with live data.
- If intermittent, wiggle-test harness, inspect for chafing, and consider securing wiring; use smoke test to detect exhaust leaks that could influence sensor behavior.
Likely causes
- Failed oxygen sensor heater (most common)
- Damaged sensor connector (corrosion or water intrusion)
- Broken or shorted heater supply/ground wire between sensor and PCM
- Blown fuse or faulty fuse link for heater circuit
- PCM heater driver failure (less common)
Fault status
Status
P0135 — Oxygen Sensor (Bank 1, Sensor 1) Heater Circuit Malfunction. Heater circuit failed to operate within expected parameters; sensor may not reach operating temperature.
Repair difficulty: Medium
Diagnostic time: 0.5 - 2.0 hours
Similar codes
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Code
P0135
HUMMER
P — Powertrain
Heated Oxygen Sensor (HO2S) Heater Performance Bank 1 Sensor 1
Views:
UK: 14
EN: 23
RU: 87
AI status
Completed
Completed
100%
Causes
- Failed O2 sensor heater element
- Open or shorted heater circuit wiring (power or ground)
- Blown fuse or faulty relay supplying heater circuit
- Corroded/poor connector or pin contact at sensor or harness
- PCM driver fault or internal short
- Aftermarket or incorrect sensor installed
Symptoms
- Check Engine Light (MIL) illuminated with P0135 stored
- Heater-related readiness monitor incomplete or in fault
- Long cold start enrichment / poor emissions until engine warms up
- Lower fuel economy or rough idle until sensor warms
- Elevated tailpipe emissions (failed emissions test)
- Possible intermittent MIL if wiring or connector is intermittent
What to check
- Retrieve freeze frame and live data with a diagnostic scan tool (confirm Bank 1 Sensor 1 identification)
- Verify vehicle-specific code is P0135 (heater circuit) and check readiness status
- Visually inspect sensor, wiring, and connector for damage, corrosion, melted insulation, or exhaust soot
- Check fuses and relays related to O2 sensor heaters
- Backprobe heater power and ground pins with ignition ON (engine off) to confirm supply voltage and control ground per factory wiring diagrams
- Measure heater resistance at sensor with connector disconnected and compare to specification
Signal parameters
- Heater resistance (cold): typically 2–20 ohms depending on sensor; consult Audi spec
- Heater supply voltage: battery voltage (approx. 12 V) with ignition ON (engine off)
- Heater control: PCM provides ground switching or a fused supply feed — verify switching behavior with scope or DVOM
- O2 sensor voltage (post-heater warmup): switching ~0.1–0.9 V in rich/lean cycles for narrowband sensors
- Heater current draw: expected few hundred mA; abnormally high indicates short, open indicates open circuit
Diagnostic algorithm
- Connect a scan tool, confirm P0135 and identify Bank 1 Sensor 1. Record freeze frame and readiness status.
- Perform a visual inspection of the sensor, connector, and wiring harness for damage, corrosion, rodent chew, or heat damage.
- With ignition OFF, disconnect sensor connector. Measure heater element resistance across heater pins; compare to Audi spec. If within spec, proceed; if open/infinite or shorted, replace sensor.
- With connector disconnected and ignition ON (engine off), measure heater supply voltage at harness pin. If no supply, check related fuses/relays and wiring back to power source.
- With connector disconnected, backprobe heater ground/control pin and monitor while cranking or with engine running if required per OEM procedure; verify PCM provides ground switching (or supply) as specified.
- If supply and control are present but heater resistance out of range, replace sensor. If heater resistance is correct but no switching/ground from PCM, inspect wiring for opens/shorts and repair. Check for shorts to battery or ground.
- If wiring and connectors are good but PCM does not command the heater, check for relevant fuse/relay and then consider PCM output testing or software update per Audi service info; contact dealer for confirmed software/TSB.
- After repair or replacement, clear codes, perform drive cycle or forced readiness, and confirm code does not return. Verify proper sensor switching and heater operation with live data.
- If intermittent, wiggle-test harness, inspect for chafing, and consider securing wiring; use smoke test to detect exhaust leaks that could influence sensor behavior.
Likely causes
- Failed oxygen sensor heater (most common)
- Damaged sensor connector (corrosion or water intrusion)
- Broken or shorted heater supply/ground wire between sensor and PCM
- Blown fuse or faulty fuse link for heater circuit
- PCM heater driver failure (less common)
Fault status
Status
P0135 — Oxygen Sensor (Bank 1, Sensor 1) Heater Circuit Malfunction. Heater circuit failed to operate within expected parameters; sensor may not reach operating temperature.
Repair difficulty: Medium
Diagnostic time: 0.5 - 2.0 hours
Similar codes
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Code
P0135
LAND ROVER
P — Powertrain
Malfunction of the heater circuit of the sensor (bank 1 sensor 1)
Views:
UK: 10
EN: 16
RU: 78
AI status
Completed
Completed
100%
Causes
- Failed O2 sensor heater element
- Open or shorted heater circuit wiring (power or ground)
- Blown fuse or faulty relay supplying heater circuit
- Corroded/poor connector or pin contact at sensor or harness
- PCM driver fault or internal short
- Aftermarket or incorrect sensor installed
Symptoms
- Check Engine Light (MIL) illuminated with P0135 stored
- Heater-related readiness monitor incomplete or in fault
- Long cold start enrichment / poor emissions until engine warms up
- Lower fuel economy or rough idle until sensor warms
- Elevated tailpipe emissions (failed emissions test)
- Possible intermittent MIL if wiring or connector is intermittent
What to check
- Retrieve freeze frame and live data with a diagnostic scan tool (confirm Bank 1 Sensor 1 identification)
- Verify vehicle-specific code is P0135 (heater circuit) and check readiness status
- Visually inspect sensor, wiring, and connector for damage, corrosion, melted insulation, or exhaust soot
- Check fuses and relays related to O2 sensor heaters
- Backprobe heater power and ground pins with ignition ON (engine off) to confirm supply voltage and control ground per factory wiring diagrams
- Measure heater resistance at sensor with connector disconnected and compare to specification
Signal parameters
- Heater resistance (cold): typically 2–20 ohms depending on sensor; consult Audi spec
- Heater supply voltage: battery voltage (approx. 12 V) with ignition ON (engine off)
- Heater control: PCM provides ground switching or a fused supply feed — verify switching behavior with scope or DVOM
- O2 sensor voltage (post-heater warmup): switching ~0.1–0.9 V in rich/lean cycles for narrowband sensors
- Heater current draw: expected few hundred mA; abnormally high indicates short, open indicates open circuit
Diagnostic algorithm
- Connect a scan tool, confirm P0135 and identify Bank 1 Sensor 1. Record freeze frame and readiness status.
- Perform a visual inspection of the sensor, connector, and wiring harness for damage, corrosion, rodent chew, or heat damage.
- With ignition OFF, disconnect sensor connector. Measure heater element resistance across heater pins; compare to Audi spec. If within spec, proceed; if open/infinite or shorted, replace sensor.
- With connector disconnected and ignition ON (engine off), measure heater supply voltage at harness pin. If no supply, check related fuses/relays and wiring back to power source.
- With connector disconnected, backprobe heater ground/control pin and monitor while cranking or with engine running if required per OEM procedure; verify PCM provides ground switching (or supply) as specified.
- If supply and control are present but heater resistance out of range, replace sensor. If heater resistance is correct but no switching/ground from PCM, inspect wiring for opens/shorts and repair. Check for shorts to battery or ground.
- If wiring and connectors are good but PCM does not command the heater, check for relevant fuse/relay and then consider PCM output testing or software update per Audi service info; contact dealer for confirmed software/TSB.
- After repair or replacement, clear codes, perform drive cycle or forced readiness, and confirm code does not return. Verify proper sensor switching and heater operation with live data.
- If intermittent, wiggle-test harness, inspect for chafing, and consider securing wiring; use smoke test to detect exhaust leaks that could influence sensor behavior.
Likely causes
- Failed oxygen sensor heater (most common)
- Damaged sensor connector (corrosion or water intrusion)
- Broken or shorted heater supply/ground wire between sensor and PCM
- Blown fuse or faulty fuse link for heater circuit
- PCM heater driver failure (less common)
Fault status
Status
P0135 — Oxygen Sensor (Bank 1, Sensor 1) Heater Circuit Malfunction. Heater circuit failed to operate within expected parameters; sensor may not reach operating temperature.
Repair difficulty: Medium
Diagnostic time: 0.5 - 2.0 hours
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Workshop Manual199,00 UAH
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Code
P0135
MITSUBISHI
P — Powertrain
Oxygen sensor(front) heater
Views:
UK: 15
EN: 25
RU: 91
AI status
Completed
Completed
100%
Causes
- Failed O2 sensor heater element
- Open or shorted heater circuit wiring (power or ground)
- Blown fuse or faulty relay supplying heater circuit
- Corroded/poor connector or pin contact at sensor or harness
- PCM driver fault or internal short
- Aftermarket or incorrect sensor installed
Symptoms
- Check Engine Light (MIL) illuminated with P0135 stored
- Heater-related readiness monitor incomplete or in fault
- Long cold start enrichment / poor emissions until engine warms up
- Lower fuel economy or rough idle until sensor warms
- Elevated tailpipe emissions (failed emissions test)
- Possible intermittent MIL if wiring or connector is intermittent
What to check
- Retrieve freeze frame and live data with a diagnostic scan tool (confirm Bank 1 Sensor 1 identification)
- Verify vehicle-specific code is P0135 (heater circuit) and check readiness status
- Visually inspect sensor, wiring, and connector for damage, corrosion, melted insulation, or exhaust soot
- Check fuses and relays related to O2 sensor heaters
- Backprobe heater power and ground pins with ignition ON (engine off) to confirm supply voltage and control ground per factory wiring diagrams
- Measure heater resistance at sensor with connector disconnected and compare to specification
Signal parameters
- Heater resistance (cold): typically 2–20 ohms depending on sensor; consult Audi spec
- Heater supply voltage: battery voltage (approx. 12 V) with ignition ON (engine off)
- Heater control: PCM provides ground switching or a fused supply feed — verify switching behavior with scope or DVOM
- O2 sensor voltage (post-heater warmup): switching ~0.1–0.9 V in rich/lean cycles for narrowband sensors
- Heater current draw: expected few hundred mA; abnormally high indicates short, open indicates open circuit
Diagnostic algorithm
- Connect a scan tool, confirm P0135 and identify Bank 1 Sensor 1. Record freeze frame and readiness status.
- Perform a visual inspection of the sensor, connector, and wiring harness for damage, corrosion, rodent chew, or heat damage.
- With ignition OFF, disconnect sensor connector. Measure heater element resistance across heater pins; compare to Audi spec. If within spec, proceed; if open/infinite or shorted, replace sensor.
- With connector disconnected and ignition ON (engine off), measure heater supply voltage at harness pin. If no supply, check related fuses/relays and wiring back to power source.
- With connector disconnected, backprobe heater ground/control pin and monitor while cranking or with engine running if required per OEM procedure; verify PCM provides ground switching (or supply) as specified.
- If supply and control are present but heater resistance out of range, replace sensor. If heater resistance is correct but no switching/ground from PCM, inspect wiring for opens/shorts and repair. Check for shorts to battery or ground.
- If wiring and connectors are good but PCM does not command the heater, check for relevant fuse/relay and then consider PCM output testing or software update per Audi service info; contact dealer for confirmed software/TSB.
- After repair or replacement, clear codes, perform drive cycle or forced readiness, and confirm code does not return. Verify proper sensor switching and heater operation with live data.
- If intermittent, wiggle-test harness, inspect for chafing, and consider securing wiring; use smoke test to detect exhaust leaks that could influence sensor behavior.
Likely causes
- Failed oxygen sensor heater (most common)
- Damaged sensor connector (corrosion or water intrusion)
- Broken or shorted heater supply/ground wire between sensor and PCM
- Blown fuse or faulty fuse link for heater circuit
- PCM heater driver failure (less common)
Fault status
Status
P0135 — Oxygen Sensor (Bank 1, Sensor 1) Heater Circuit Malfunction. Heater circuit failed to operate within expected parameters; sensor may not reach operating temperature.
Repair difficulty: Medium
Diagnostic time: 0.5 - 2.0 hours
Similar codes
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👍 Like
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Send to email