P2138

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

ACCELERATOR PEDAL POSITION SENSOR (MAIN AND SUB) RANGE/PERFORMANCE CIRCUIT

Accelerator Pedal Position Sensor (Main) Circuit (Part 1):

Accelerator Pedal Position Sensor (Main) Circuit (Part 2):

Accelerator 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 0.2 second: [accelerator pedal position sensor (main) output voltage-accelerator pedal position sensor (sub) output 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.

OBD-II DRIVE CYCLE PATTERN
None.

TROUBLESHOOTING HINTS (The most likely causes for this code to be set are:)
- Accelerator pedal position sensor failed.
- Connector damage.
- Harness 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-123 at accelerator pedal position sensor and harness connector B-11 at ECM 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 4.

STEP 2. Check for harness damage between accelerator pedal position sensor connector C-123 and ECM connector B-11.

1. Disconnect the connector C-123 and B-11 measure at the harness side.
2. Measure the resistance between connector C-123 and connector B-11.
a. Connector C-123 (terminal No. 1) and connector B-11 (terminal No. 75).
b. Connector C-123 (terminal No. 2) and connector B-11 (terminal No. 76).
c. Connector C-123 (terminal No. 3) and connector B-11 (terminal No. 74).
d. Connector C-123 (terminal No. 4) and connector B-11 (terminal No. 78).
e. Connector C-123 (terminal No. 5) and connector B-11 (terminal No. 79).
f. Connector C-123 (terminal No. 6) and connector B-11 (terminal No. 77).
- Should be less than 2 ohms.

Q: Is the measured resistance less than 2 ohms?

YES : Go to Step 3.

NO : Repair it. Then go to Step 4.

STEP 3. Using scan tool MB991958, check data list.

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. Check the following items in the data list. Refer to MFI Data List Reference Table. Datal List Reference Table
a. Item 11: Accelerator Pedal Position Sensor (main).
b. Item 12: Accelerator Pedal Position Sensor (sub).

4. Turn the ignition switch to the "LOCK" (OFF) position.

Q: Are they operating properly?

YES : Go to Step 4.

NO : Repair or replace it. Then go to Step 4.

STEP 4. Using scan tool MB991958, read the diagnostic trouble code (DTC).

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

Q: Is DTC P2138 set?

YES : Retry the troubleshooting.

NO : The inspection is complete.