P1148
Variable distribution electrovalve (VTC) open circuit
Causes
- Broken or disconnected wiring between ECU and VTC solenoid
- Corroded or damaged connector at the solenoid
- Open or shorted solenoid coil (internal failure)
- Blown fuse or poor power/ground supply to the solenoid circuit
- Oil contamination or mechanical seizure of the solenoid
- Faulty ECU output driver
Symptoms
- Malfunction Indicator Lamp (MIL) / check engine light illuminated
- Reduced engine performance or loss of torque
- Rough idle or unstable idle speed
- Increased fuel consumption
- Possible engine noise on startup (valvetrain timing off)
- Ill-defined or intermittent drivability issues if wiring is intermittent
What to check
- Read and record all stored codes and freeze-frame data with a scan tool
- Visual inspection of the solenoid connector and wiring for damage, corrosion, oil intrusion or pin deformation
- Check related fuses and engine ground connections
- Measure battery voltage at the solenoid power pin with key ON
- Measure solenoid coil resistance with connector disconnected
- Back-probe the control wire with engine cranking/running to observe voltage/PWM
Signal parameters
- Supply/reference voltage: approximately battery voltage with key ON (typically ~11–14 V)
- Control signal: ECU uses a switched/PWM output. Voltage on control line will be pulsed between ~0–battery voltage; duty cycle varies with commanded cam timing
- Typical coil resistance (manufacturer dependent): commonly in the range of ~6–25 ohms (measure and compare to service data if available)
- PWM frequency varies by design (tens to hundreds of Hz). Use OEM data or a scope to confirm exact frequency
Diagnostic algorithm
- Retrieve freeze-frame and all related codes. Note engine conditions when code set.
- Perform a visual inspection of the VTC solenoid, connector and wiring harness for damage, oil contamination or corrosion.
- With ignition OFF disconnect solenoid connector and measure coil resistance across solenoid pins. Compare to OEM spec (open circuit indicates failed solenoid).
- With ignition ON, measure battery voltage at the solenoid power pin; verify a good ground at the ground pin.
- Reconnect and back-probe the control lead. Crank or run the engine and observe the control signal with a multimeter or scope. Look for pulsed voltage; an absent signal suggests wiring/ECU issue.
- Check continuity between the solenoid connector and the ECU connector to confirm no open or short to ground/voltage.
- Perform a wiggle test on harness/connectors while monitoring the live data and code status to detect intermittent faults.
- If wiring and connectors are good but the solenoid is open, replace the solenoid and clear codes. Retest for proper operation.
- If new solenoid still reports P1148, test the ECU output driver for the VTC channel (scope preferred) or consult manufacturer service data; ECU repair/replacement may be required as a last resort.
Likely causes
- Loose/disconnected or corroded connector at the VTC solenoid
- Open circuit in wiring (broken wire, pin pushed out)
- Failed solenoid coil (open)
- Blown fuse or poor ground
Fault status
Similar codes
P1148
Variable distribution electrovalve (VTC) open circuit
Causes
- Broken or disconnected wiring between ECU and VTC solenoid
- Corroded or damaged connector at the solenoid
- Open or shorted solenoid coil (internal failure)
- Blown fuse or poor power/ground supply to the solenoid circuit
- Oil contamination or mechanical seizure of the solenoid
- Faulty ECU output driver
Symptoms
- Malfunction Indicator Lamp (MIL) / check engine light illuminated
- Reduced engine performance or loss of torque
- Rough idle or unstable idle speed
- Increased fuel consumption
- Possible engine noise on startup (valvetrain timing off)
- Ill-defined or intermittent drivability issues if wiring is intermittent
What to check
- Read and record all stored codes and freeze-frame data with a scan tool
- Visual inspection of the solenoid connector and wiring for damage, corrosion, oil intrusion or pin deformation
- Check related fuses and engine ground connections
- Measure battery voltage at the solenoid power pin with key ON
- Measure solenoid coil resistance with connector disconnected
- Back-probe the control wire with engine cranking/running to observe voltage/PWM
Signal parameters
- Supply/reference voltage: approximately battery voltage with key ON (typically ~11–14 V)
- Control signal: ECU uses a switched/PWM output. Voltage on control line will be pulsed between ~0–battery voltage; duty cycle varies with commanded cam timing
- Typical coil resistance (manufacturer dependent): commonly in the range of ~6–25 ohms (measure and compare to service data if available)
- PWM frequency varies by design (tens to hundreds of Hz). Use OEM data or a scope to confirm exact frequency
Diagnostic algorithm
- Retrieve freeze-frame and all related codes. Note engine conditions when code set.
- Perform a visual inspection of the VTC solenoid, connector and wiring harness for damage, oil contamination or corrosion.
- With ignition OFF disconnect solenoid connector and measure coil resistance across solenoid pins. Compare to OEM spec (open circuit indicates failed solenoid).
- With ignition ON, measure battery voltage at the solenoid power pin; verify a good ground at the ground pin.
- Reconnect and back-probe the control lead. Crank or run the engine and observe the control signal with a multimeter or scope. Look for pulsed voltage; an absent signal suggests wiring/ECU issue.
- Check continuity between the solenoid connector and the ECU connector to confirm no open or short to ground/voltage.
- Perform a wiggle test on harness/connectors while monitoring the live data and code status to detect intermittent faults.
- If wiring and connectors are good but the solenoid is open, replace the solenoid and clear codes. Retest for proper operation.
- If new solenoid still reports P1148, test the ECU output driver for the VTC channel (scope preferred) or consult manufacturer service data; ECU repair/replacement may be required as a last resort.
Likely causes
- Loose/disconnected or corroded connector at the VTC solenoid
- Open circuit in wiring (broken wire, pin pushed out)
- Failed solenoid coil (open)
- Blown fuse or poor ground
Fault status
Similar codes
P1148
Closed Loop Control Function Bank 1
Causes
- Broken or disconnected wiring between ECU and VTC solenoid
- Corroded or damaged connector at the solenoid
- Open or shorted solenoid coil (internal failure)
- Blown fuse or poor power/ground supply to the solenoid circuit
- Oil contamination or mechanical seizure of the solenoid
- Faulty ECU output driver
Symptoms
- Malfunction Indicator Lamp (MIL) / check engine light illuminated
- Reduced engine performance or loss of torque
- Rough idle or unstable idle speed
- Increased fuel consumption
- Possible engine noise on startup (valvetrain timing off)
- Ill-defined or intermittent drivability issues if wiring is intermittent
What to check
- Read and record all stored codes and freeze-frame data with a scan tool
- Visual inspection of the solenoid connector and wiring for damage, corrosion, oil intrusion or pin deformation
- Check related fuses and engine ground connections
- Measure battery voltage at the solenoid power pin with key ON
- Measure solenoid coil resistance with connector disconnected
- Back-probe the control wire with engine cranking/running to observe voltage/PWM
Signal parameters
- Supply/reference voltage: approximately battery voltage with key ON (typically ~11–14 V)
- Control signal: ECU uses a switched/PWM output. Voltage on control line will be pulsed between ~0–battery voltage; duty cycle varies with commanded cam timing
- Typical coil resistance (manufacturer dependent): commonly in the range of ~6–25 ohms (measure and compare to service data if available)
- PWM frequency varies by design (tens to hundreds of Hz). Use OEM data or a scope to confirm exact frequency
Diagnostic algorithm
- Retrieve freeze-frame and all related codes. Note engine conditions when code set.
- Perform a visual inspection of the VTC solenoid, connector and wiring harness for damage, oil contamination or corrosion.
- With ignition OFF disconnect solenoid connector and measure coil resistance across solenoid pins. Compare to OEM spec (open circuit indicates failed solenoid).
- With ignition ON, measure battery voltage at the solenoid power pin; verify a good ground at the ground pin.
- Reconnect and back-probe the control lead. Crank or run the engine and observe the control signal with a multimeter or scope. Look for pulsed voltage; an absent signal suggests wiring/ECU issue.
- Check continuity between the solenoid connector and the ECU connector to confirm no open or short to ground/voltage.
- Perform a wiggle test on harness/connectors while monitoring the live data and code status to detect intermittent faults.
- If wiring and connectors are good but the solenoid is open, replace the solenoid and clear codes. Retest for proper operation.
- If new solenoid still reports P1148, test the ECU output driver for the VTC channel (scope preferred) or consult manufacturer service data; ECU repair/replacement may be required as a last resort.
Likely causes
- Loose/disconnected or corroded connector at the VTC solenoid
- Open circuit in wiring (broken wire, pin pushed out)
- Failed solenoid coil (open)
- Blown fuse or poor ground
Fault status
Similar codes
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P1148
Closed Loop Control Bank 1
Causes
- Broken or disconnected wiring between ECU and VTC solenoid
- Corroded or damaged connector at the solenoid
- Open or shorted solenoid coil (internal failure)
- Blown fuse or poor power/ground supply to the solenoid circuit
- Oil contamination or mechanical seizure of the solenoid
- Faulty ECU output driver
Symptoms
- Malfunction Indicator Lamp (MIL) / check engine light illuminated
- Reduced engine performance or loss of torque
- Rough idle or unstable idle speed
- Increased fuel consumption
- Possible engine noise on startup (valvetrain timing off)
- Ill-defined or intermittent drivability issues if wiring is intermittent
What to check
- Read and record all stored codes and freeze-frame data with a scan tool
- Visual inspection of the solenoid connector and wiring for damage, corrosion, oil intrusion or pin deformation
- Check related fuses and engine ground connections
- Measure battery voltage at the solenoid power pin with key ON
- Measure solenoid coil resistance with connector disconnected
- Back-probe the control wire with engine cranking/running to observe voltage/PWM
Signal parameters
- Supply/reference voltage: approximately battery voltage with key ON (typically ~11–14 V)
- Control signal: ECU uses a switched/PWM output. Voltage on control line will be pulsed between ~0–battery voltage; duty cycle varies with commanded cam timing
- Typical coil resistance (manufacturer dependent): commonly in the range of ~6–25 ohms (measure and compare to service data if available)
- PWM frequency varies by design (tens to hundreds of Hz). Use OEM data or a scope to confirm exact frequency
Diagnostic algorithm
- Retrieve freeze-frame and all related codes. Note engine conditions when code set.
- Perform a visual inspection of the VTC solenoid, connector and wiring harness for damage, oil contamination or corrosion.
- With ignition OFF disconnect solenoid connector and measure coil resistance across solenoid pins. Compare to OEM spec (open circuit indicates failed solenoid).
- With ignition ON, measure battery voltage at the solenoid power pin; verify a good ground at the ground pin.
- Reconnect and back-probe the control lead. Crank or run the engine and observe the control signal with a multimeter or scope. Look for pulsed voltage; an absent signal suggests wiring/ECU issue.
- Check continuity between the solenoid connector and the ECU connector to confirm no open or short to ground/voltage.
- Perform a wiggle test on harness/connectors while monitoring the live data and code status to detect intermittent faults.
- If wiring and connectors are good but the solenoid is open, replace the solenoid and clear codes. Retest for proper operation.
- If new solenoid still reports P1148, test the ECU output driver for the VTC channel (scope preferred) or consult manufacturer service data; ECU repair/replacement may be required as a last resort.
Likely causes
- Loose/disconnected or corroded connector at the VTC solenoid
- Open circuit in wiring (broken wire, pin pushed out)
- Failed solenoid coil (open)
- Blown fuse or poor ground
Fault status
Similar codes
P1148
Variable distribution electrovalve (VTC) open circuit
Causes
- Broken or disconnected wiring between ECU and VTC solenoid
- Corroded or damaged connector at the solenoid
- Open or shorted solenoid coil (internal failure)
- Blown fuse or poor power/ground supply to the solenoid circuit
- Oil contamination or mechanical seizure of the solenoid
- Faulty ECU output driver
Symptoms
- Malfunction Indicator Lamp (MIL) / check engine light illuminated
- Reduced engine performance or loss of torque
- Rough idle or unstable idle speed
- Increased fuel consumption
- Possible engine noise on startup (valvetrain timing off)
- Ill-defined or intermittent drivability issues if wiring is intermittent
What to check
- Read and record all stored codes and freeze-frame data with a scan tool
- Visual inspection of the solenoid connector and wiring for damage, corrosion, oil intrusion or pin deformation
- Check related fuses and engine ground connections
- Measure battery voltage at the solenoid power pin with key ON
- Measure solenoid coil resistance with connector disconnected
- Back-probe the control wire with engine cranking/running to observe voltage/PWM
Signal parameters
- Supply/reference voltage: approximately battery voltage with key ON (typically ~11–14 V)
- Control signal: ECU uses a switched/PWM output. Voltage on control line will be pulsed between ~0–battery voltage; duty cycle varies with commanded cam timing
- Typical coil resistance (manufacturer dependent): commonly in the range of ~6–25 ohms (measure and compare to service data if available)
- PWM frequency varies by design (tens to hundreds of Hz). Use OEM data or a scope to confirm exact frequency
Diagnostic algorithm
- Retrieve freeze-frame and all related codes. Note engine conditions when code set.
- Perform a visual inspection of the VTC solenoid, connector and wiring harness for damage, oil contamination or corrosion.
- With ignition OFF disconnect solenoid connector and measure coil resistance across solenoid pins. Compare to OEM spec (open circuit indicates failed solenoid).
- With ignition ON, measure battery voltage at the solenoid power pin; verify a good ground at the ground pin.
- Reconnect and back-probe the control lead. Crank or run the engine and observe the control signal with a multimeter or scope. Look for pulsed voltage; an absent signal suggests wiring/ECU issue.
- Check continuity between the solenoid connector and the ECU connector to confirm no open or short to ground/voltage.
- Perform a wiggle test on harness/connectors while monitoring the live data and code status to detect intermittent faults.
- If wiring and connectors are good but the solenoid is open, replace the solenoid and clear codes. Retest for proper operation.
- If new solenoid still reports P1148, test the ECU output driver for the VTC channel (scope preferred) or consult manufacturer service data; ECU repair/replacement may be required as a last resort.
Likely causes
- Loose/disconnected or corroded connector at the VTC solenoid
- Open circuit in wiring (broken wire, pin pushed out)
- Failed solenoid coil (open)
- Blown fuse or poor ground
Fault status
Similar codes
P1148
Oxygen Sensor Control Bank 2 System Too Rich
Causes
- Broken or disconnected wiring between ECU and VTC solenoid
- Corroded or damaged connector at the solenoid
- Open or shorted solenoid coil (internal failure)
- Blown fuse or poor power/ground supply to the solenoid circuit
- Oil contamination or mechanical seizure of the solenoid
- Faulty ECU output driver
Symptoms
- Malfunction Indicator Lamp (MIL) / check engine light illuminated
- Reduced engine performance or loss of torque
- Rough idle or unstable idle speed
- Increased fuel consumption
- Possible engine noise on startup (valvetrain timing off)
- Ill-defined or intermittent drivability issues if wiring is intermittent
What to check
- Read and record all stored codes and freeze-frame data with a scan tool
- Visual inspection of the solenoid connector and wiring for damage, corrosion, oil intrusion or pin deformation
- Check related fuses and engine ground connections
- Measure battery voltage at the solenoid power pin with key ON
- Measure solenoid coil resistance with connector disconnected
- Back-probe the control wire with engine cranking/running to observe voltage/PWM
Signal parameters
- Supply/reference voltage: approximately battery voltage with key ON (typically ~11–14 V)
- Control signal: ECU uses a switched/PWM output. Voltage on control line will be pulsed between ~0–battery voltage; duty cycle varies with commanded cam timing
- Typical coil resistance (manufacturer dependent): commonly in the range of ~6–25 ohms (measure and compare to service data if available)
- PWM frequency varies by design (tens to hundreds of Hz). Use OEM data or a scope to confirm exact frequency
Diagnostic algorithm
- Retrieve freeze-frame and all related codes. Note engine conditions when code set.
- Perform a visual inspection of the VTC solenoid, connector and wiring harness for damage, oil contamination or corrosion.
- With ignition OFF disconnect solenoid connector and measure coil resistance across solenoid pins. Compare to OEM spec (open circuit indicates failed solenoid).
- With ignition ON, measure battery voltage at the solenoid power pin; verify a good ground at the ground pin.
- Reconnect and back-probe the control lead. Crank or run the engine and observe the control signal with a multimeter or scope. Look for pulsed voltage; an absent signal suggests wiring/ECU issue.
- Check continuity between the solenoid connector and the ECU connector to confirm no open or short to ground/voltage.
- Perform a wiggle test on harness/connectors while monitoring the live data and code status to detect intermittent faults.
- If wiring and connectors are good but the solenoid is open, replace the solenoid and clear codes. Retest for proper operation.
- If new solenoid still reports P1148, test the ECU output driver for the VTC channel (scope preferred) or consult manufacturer service data; ECU repair/replacement may be required as a last resort.
Likely causes
- Loose/disconnected or corroded connector at the VTC solenoid
- Open circuit in wiring (broken wire, pin pushed out)
- Failed solenoid coil (open)
- Blown fuse or poor ground
Fault status
Similar codes
Manual library for VOLKSWAGEN
Browse 139 VOLKSWAGEN manuals: repair procedures, diagnostics, wiring diagrams, component locations, service data and Labor Times by year, model and trim.
VOLKSWAGEN
-
VOLKSWAGEN: 2021
-
Atlas
- S, AWD
- S, FWD
- SE, 2.0L Eng VIN P, AWD
- SE, 2.0L Eng VIN P, FWD
- SE, 3.6L Eng VIN R, AWD
- SE, 3.6L Eng VIN R, FWD
- SEL, 2.0L Eng VIN P · 2.0L Eng VIN P2021: Atlas SEL
- SEL, 3.6L Eng VIN R, AWD
- SEL, 3.6L Eng VIN R, FWD
- SEL Premium, 2.0L Eng VIN P · 2.0L Eng VIN P2021: Atlas SEL Premium
- SEL Premium, 3.6L Eng VIN R · 3.6L Eng VIN R2021: Atlas SEL Premium
- SEL Premium R-Line
- SEL R-Line, AWD
- SEL R-Line, FWD
- SE R-Line, AWD
- SE R-Line, FWD
-
Atlas Cross Sport
- S, AWD
- S, FWD
- SE, 2.0L Eng VIN C, AWD
- SE, 2.0L Eng VIN C, FWD
- SE, 3.6L Eng VIN E, AWD
- SE, 3.6L Eng VIN E, FWD
- SEL, 2.0L Eng VIN C · 2.0L Eng VIN C2021: Atlas Cross Sport SEL
- SEL, 3.6L Eng VIN E, AWD
- SEL, 3.6L Eng VIN E, FWD
- SEL Premium, 2.0L Eng VIN C · 2.0L Eng VIN C2021: Atlas Cross Sport SEL Premium
- SEL Premium, 3.6L Eng VIN E · 3.6L Eng VIN E2021: Atlas Cross Sport SEL Premium
- SEL Premium R-Line
- SEL R-Line, AWD
- SEL R-Line, FWD
- SE R-Line, AWD
- SE R-Line, FWD
-
VOLKSWAGEN: 2020
-
Atlas
- S, 2.0L Eng VIN P · 2.0L Eng VIN P2020: Atlas S
- S, 3.6L Eng VIN R · 3.6L Eng VIN R2020: Atlas S
- SE, 2.0L Eng VIN P · 2.0L Eng VIN P2020: Atlas SE
- SE, 3.6L Eng VIN R, AWD
- SE, 3.6L Eng VIN R, FWD
- SEL, 2.0L Eng VIN P · 2.0L Eng VIN P2020: Atlas SEL
- SEL, 3.6L Eng VIN R, AWD
- SEL, 3.6L Eng VIN R, FWD
- SEL Premium
- SEL R-Line, AWD
- SEL R-Line, FWD
- SE R-Line, AWD
- SE R-Line, FWD
-
Atlas Cross Sport
- S, AWD
- S, FWD
- SE, 2.0L Eng VIN C, AWD
- SE, 2.0L Eng VIN C, FWD
- SE, 3.6L Eng VIN E, AWD
- SE, 3.6L Eng VIN E, FWD
- SEL, 2.0L Eng VIN C, AWD
- SEL, 2.0L Eng VIN C, FWD
- SEL, 3.6L Eng VIN E, AWD
- SEL, 3.6L Eng VIN E, FWD
- SEL Premium
- SEL Premium R-Line
- SEL R-Line, AWD
- SEL R-Line, FWD
- SE R-Line, AWD
- SE R-Line, FWD
-
Jetta
- GLI Autobahn, Automatic DCT Trans
- GLI Autobahn, Standard Trans
- GLI S, Automatic DCT Trans
- GLI S, Standard Trans
- R-Line, 1.4L Eng VIN 5, Automatic Trans
- R-Line, 1.4L Eng VIN 5, Standard Trans
- R-Line, 1.4L Eng VIN B · 1.4L Eng VIN B2020: Jetta R-Line
- S, 1.4L Eng VIN 5, Automatic Trans
- S, 1.4L Eng VIN 5, Standard Trans
- S, 1.4L Eng VIN B · 1.4L Eng VIN B2020: Jetta S
- SE, 1.4L Eng VIN 5 · 1.4L Eng VIN 52020: Jetta SE
- SE, 1.4L Eng VIN B · 1.4L Eng VIN B2020: Jetta SE
- SEL, 1.4L Eng VIN 5 · 1.4L Eng VIN 52020: Jetta SEL
- SEL, 1.4L Eng VIN B · 1.4L Eng VIN B2020: Jetta SEL
- SEL Premium, 1.4L Eng VIN 5 · 1.4L Eng VIN 52020: Jetta SEL Premium
- SEL Premium, 1.4L Eng VIN B · 1.4L Eng VIN B2020: Jetta SEL Premium
