P2138

DTC P2138: Accelerator Pedal Position Sensor (main and sub) Range/Performance Problem

ACCELERATOR PEDAL POSITION SENSOR (main and sub) RANGE/PERFORMANCE PROBLEM CIRCUIT

Accelerator Pedal Position Sensor (Main) Circuit:

Acceleration Pedal Position Sensor (SUB) Circuit:

CIRCUIT OPERATION

Accelerator Pedal Position Sensor (main) Circuit Low Input
- A 5-volt power supply is applied on the accelerator pedal position sensor (main) power terminal (terminal No. 1) from the ECM (terminal No. 75).
- A voltage that is according to the accelerator opening angle is sent to the ECM (terminal No. 74) from the accelerator pedal position sensor (main) output terminal (terminal No. 3).
- The ground terminal (terminal No. 2) is grounded with ECM (terminal No. 76).

Accelerator Pedal Position Sensor (sub) Circuit Low Input
- A 5-volt power supply is applied on the accelerator pedal position sensor (sub) power terminal (terminal No. 4) from the ECM (terminal No. 78).
- A voltage that is according to the accelerator opening angle is sent to the ECM (terminal No. 77) from the accelerator pedal position sensor (sub) output terminal (terminal No. 6).
- The ground terminal (terminal No. 5) is grounded with ECM (terminal No. 79).

TECHNICAL DESCRIPTION
- ECM checks the accelerator pedal position sensor output signal characteristics for abnormal conditions.

DESCRIPTIONS OF MONITOR METHODS
Detect malfunction if the relation between accelerator pedal position sensor (main) and accelerator pedal position sensor (sub) is wrong.

MONITOR EXECUTION
Continuous

MONITOR EXECUTION CONDITIONS (Other monitor and Sensor)

Other Monitor (There is no temporary DTC stored in memory for the item monitored below)
- Not applicable

Sensor (The sensor below is determined to be normal)
- Not applicable

DTC SET CONDITIONS [Range/Performance problem-relation between main and sub>

Logic Flow Chart:

Check Conditions
- Change of accelerator pedal position sensor (sub) output voltage per 25 milliseconds is lower than 0.06 volt.

Judgement Criterion
- Voltage obtained with the formula given below is 0.4 volt or higher for 0.3 second: [accelerator pedal position sensor (sub) voltage - accelerator pedal position sensor (main) voltage].

NOTE: The accelerator pedal position sensor voltage used for the judgement is converted into the accelerator pedal position sensor voltage for the internal processing by the ECM.

DTC SET CONDITIONS [Range/Performance problem -relation between main and sub>

Logic Flow Chart:

Check Conditions
- Change of accelerator pedal position sensor (sub) output voltage per 25 milliseconds is lower than 0.06 volt.

Judgement Criterion
- Voltage obtained with the formula given below is 0.4 volt or higher for 0.2 second: [accelerator pedal position sensor (main) voltage - accelerator pedal position sensor (sub) voltage].

NOTE: The accelerator pedal position sensor voltage used for the judgement is converted into the accelerator pedal position sensor voltage for the internal processing by the ECM.

FAIL-SAFE AND BACKUP FUNCTION
- Throttle opening degree is restricted.
- Throttle opening degree position is in default position if accelerator pedal position sensor (sub) fails.

OBD-II DRIVE CYCLE PATTERN
None

TROUBLESHOOTING HINTS (The most likely causes for this code to be set are:)
- Accelerator pedal position sensor failed.
- Harness damage in accelerator pedal position sensor circuit or connector damage.
- ECM failed.

DIAGNOSIS

Required Special Tools:
- MB991958: Scan tool (M.U.T.-III Sub Assembly)
- MB991824: V.C.I.
- MB991827: USB Cable
- MB991910: Main Harness A

STEP 1. Check harness connector C-01 at accelerator pedal position sensor for damage.

Q: Is the harness connector in good condition?

YES : Go to Step 2.

NO : Repair or replace it. Refer to General (Electrical), Harness Connector Inspection. Then go to Step 16.

STEP 2. Check the continuity at accelerator pedal position sensor harness side connector C-01.

1. Disconnect the connector C-01 and measure at the harness side.

2. Measure the continuity between terminal No. 2 and ground.
- Continuity (2 ohms or less)

Q: Does continuity exist?

YES : Go to Step 6.

NO : Go to Step 3.

STEP 3. Check harness connector B-10 at ECM for damage.

Q: Is the harness connector in good condition?

YES : Go to Step 4.

NO : Repair or replace it. Refer to General (Electrical), Harness Connector Inspection. Then go to Step 16.

STEP 4. Check for harness damage between accelerator pedal position sensor connector C-01 (terminal No. 2) and ECM connector B-10 (terminal No. 76).

Q: Is the harness wire in good condition?

YES : Go to Step 5.

NO : Repair it. Then go to Step 16.

STEP 5. Using scan tool MB991958, read the diagnostic trouble code (DTC).

2. Measure the continuity between terminal No. 5 and ground.
- Continuity (2 ohms or less)

Q: Does continuity exist?

YES : Go to Step 10.

NO : Go to Step 7.

STEP 7. Check harness connector B-10 at ECM for damage.

Q: Is the harness connector in good condition?

YES : Go to Step 8.

NO : Repair or replace it. Refer to General (Electrical), Harness Connector Inspection. Then go to Step 16.

STEP 8. Check for harness damage between accelerator pedal position sensor connector C-01 (terminal No. 5) and ECM connector B-10 (terminal No. 79).

Q: Is the harness wire in good condition?

YES : Go to Step 9.

NO : Repair it. Then go to Step 16.

STEP 9. Using scan tool MB991958, read the diagnostic trouble code (DTC).

CAUTION: To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.

1. Connect scan tool MB991958 to the data link connector.
2. Turn the ignition switch to the "ON" position.
3. After the DTC has been deleted, read the DTC again.
4. Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is DTC P2138 set?

YES : Replace the ECM. When the ECM is replaced, register the ID code. Refer to Keyless Operation System (KOS), ID Code Registration Necessity Judgment Table [Vehicles with KOS> or Wireless Control Module, ID Codes Registration Judgment Table [Vehicles with WCM>. Then go to Step 16.

NO : It can be assumed that this malfunction is intermittent. Refer to General (Body and Chassis), How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions.

STEP 10. Check harness connector B-10 at ECM for damage.

Q: Is the harness connector in good condition?

YES : Go to Step 11.

NO : Repair or replace it. Refer to General (Electrical), Harness Connector Inspection. Then go to Step 16.

STEP 11. Check for harness damage between accelerator pedal position sensor connector C-01 (terminal No. 1) and ECM connector B-10 (terminal No. 75).

Q: Is the harness wire in good condition?

YES : Go to Step 12.

NO : Repair it. Then go to Step 16.

STEP 12. Check for harness damage between accelerator pedal position sensor connector C-01 (terminal No. 4) and ECM connector B-10 (terminal No. 78).

Q: Is the harness wire in good condition?

YES : Go to Step 13.

NO : Repair it. Then go to Step 16.

STEP 13. Check for harness damage between accelerator pedal position sensor connector C-01 (terminal No. 3) and ECM connector B-10 (terminal No. 74).

Q: Is the harness wire in good condition?

YES : Go to Step 14.

NO : Repair it. Then go to Step 16.

STEP 14. Check for harness damage between accelerator pedal position sensor connector C-01 (terminal No. 6) and ECM connector B-10 (terminal No. 77).

Q: Is the harness wire in good condition?

YES : Go to Step 15.

NO : Repair it. Then go to Step 16.

STEP 15. Replace the accelerator pedal position sensor.

1. Replace the accelerator pedal position sensor.
2. Turn the ignition switch to the "ON" position.
3. After the DTC has been deleted, read the DTC again.
4. Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is DTC P2138 set?

YES : Replace the ECM. When the ECM is replaced, register the ID code. Refer to Keyless Operation System (KOS), ID Code Registration Necessity Judgment Table [Vehicles with KOS> or Wireless Control Module, ID Codes Registration Judgment Table [Vehicles with WCM>. Then go to Step 16.

NO : The inspection is complete.

STEP 16. Using scan tool MB991958, read the diagnostic trouble code (DTC).