DTC P0121 [MZR-CD (RF Turbo)]

BME010200100W30

DTC P0121

Accelerator position sensor No.1 circuit performance problem

DETECTION CONDITION

• PCM monitors input voltage from accelerator position sensor No.1 while engine is running. If input voltage from accelerator position sensor No.1 is above 1.3 V when accelerator pedal is depressed, PCM determines accelerator position sensor No.1 circuit performance problem.

POSSIBLE CAUSE

• Accelerator position sensor No.1 malfunction
• Connector or terminal malfunction
• Voltage drops in GND circuit
• Accelerator position sensor misadjustment
• PCM malfunction

Diagnostic procedure

STEP

INSPECTION

ACTION

1
VERIFY RELATED REPAIR INFORMATION AVAILABILITY
• Check for related Service Information availability.
• Is any related repair information available?
Yes
Perform repair or diagnosis according to available Service Information.
• If vehicle is not repaired, go to next step.
No
Go to next step.
2
INSPECT POOR CONNECTION OF ACCELERATOR POSITION SENSOR NO.1 CONNECTOR
• Turn engine switch to OFF.
• Inspect for poor connection (damaged, pulled-out terminals, corrosion, etc.).
• Is there any malfunction?
Yes
Repair or replace suspected terminal, go to Step 6.
No
Go to next step.
3
INSPECT ACCELERATOR POSITION SENSOR NO.1 GND CIRCUIT FOR VOLTAGE DROP
• Turn engine switch to OFF.
• Inspect resistance between accelerator position sensor terminal D and body GND.
• Is resistance approx. 0 ohm?
Yes
Go to next step.
No
Repair or replace suspected terminal, go to Step 6.
4
INSPECT ACCELERATOR POSITION SENSOR NO.1
• Inspect accelerator position sensor No.1.
• Is there any malfunction?
Yes
Adjust or replace accelerator position sensor, go to Step 6.
No
Go to next step.
5
INSPECT POOR CONNECTION OF PCM CONNECTOR
• Turn engine switch to OFF.
• Inspect for poor connection (damaged, pulled-out terminals, corrosion, etc.).
• Is there any malfunction?
Yes
Repair or replace suspected terminal, go to next step.
No
Go to next step.
6
VERIFY TROUBLESHOOTING OF DTC P0121 COMPLETED
• Make sure to reconnect all disconnected connectors.
• Clear DTC from PCM memory using WDS or equivalent.
• Start engine.
• Is same DTC present?
Yes
Replace PCM, go to next step.
No
Go to next step.
7
VERIFY AFTER REPAIR PROCEDURE
• Perform "After Repair Procedure".
• Is there any DTC present?
Yes
Go to applicable DTC inspection.
No
Troubleshooting completed.