P2128
DTC P2128: Accelerator Pedal Position Sensor (Sub) Circuit High InputCAUTION: If DTC P2128 has been set, TCL related DTC U1120 is also set. After P2128 has been diagnosed, don't forget to erase DTC U1120.
Accelerator Pedal Position Sensor (Sub) Circuit:
CIRCUIT OPERATION
- A 5-volt power supply is applied on the accelerator pedal position sensor (sub) power terminal (terminal No. 4) from the PCM (terminal No. 21). The ground terminal (terminal No. 5) is grounded with PCM (terminal No. 22).
TECHNICAL DESCRIPTION
- The accelerator pedal position sensor (sub) outputs voltage which corresponds to the accelerator pedal depression.
- The PCM checks whether the voltage is within a specified range.
DESCRIPTIONS OF MONITOR METHODS
Accelerator pedal position sensor (sub) output voltage is out of specified range.
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
Logic Flow Chart:
Logic Flow Chart
Check Condition
- Ignition switch is "ON" position.
Judgement Criterion
- Accelerator pedal position sensor (sub) output voltage is 4.8 volts or higher for 0.3 second.
OBD-II DRIVE CYCLE PATTERN
None.
TROUBLESHOOTING HINTS (The most likely causes for this code to be set are:)
- Accelerator pedal position sensor failed.
- Open accelerator pedal position sensor (sub) circuit, harness damage, or connector damage.
- PCM 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. Using scan tool MB991958, check data list item 12: Accelerator Pedal Position Sensor (sub).
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. Set scan tool MB991958 to the data reading mode for item 12, Accelerator Pedal Position Sensor (sub).
- Output voltage is between 435 and 1,035 millivolts when foot is released from accelerator pedal.
- Output voltage is 3,600 millivolts or more when accelerator pedal is fully depressed.
4. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the sensor operating properly?
YES: It can be assumed that this malfunction is intermittent. Refer to How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions.
NO: Go to Step 2.
STEP 2. Check harness connector C-28 at accelerator pedal position sensor for damage.
Q: Is the harness connector in good condition?
YES: Go to Step 3.
NO: Repair or replace it. Then go to Step 8.
STEP 3. Check for continuity at accelerator pedal position sensor harness side connector C-28.
1. Disconnect the connector C-28 and measure at the harness side.
2. Measure the continuity between terminal No. 5 and ground.
- Continuity (2 Ohms or less).
Q: Does continuity exist?
YES: Go to Step 6.
NO: Go to Step 4.
STEP 4. Check harness connector B-19 at PCM for damage.
Q: Is the harness connector in good condition?
YES: Go to Step 5.
NO: Repair or replace it. Then go to Step 8.
STEP 5. Check for open circuit and harness damage between accelerator pedal position sensor connector C-28 (terminal No. 5) and PCM connector B-19 (terminal No. 22).
Q: Is the harness wire in good condition?
YES: Go to Step 7.
NO: Repair it. Then go to Step 8.
STEP 6. 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 P2128 set?
YES: Replace the PCM. When the PCM is replaced, register the encrypted code. Refer to Encrypted Code Registration Criteria Table. Then go to Step 8.
NO: The inspection is complete.
STEP 7. Using scan tool MB991958, check data list item 12: Accelerator Pedal Position Sensor (sub).
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. Set scan tool MB991958 to the data reading mode for item 12, Accelerator Pedal Position Sensor (sub).
- Output voltage is between 435 and 1,035 millivolts when foot is released from accelerator pedal.
- Output voltage is 3,600 millivolts or more when accelerator pedal is fully depressed.
4. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the sensor operating properly?
YES: It can be assumed that this malfunction is intermittent. Refer to How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions.
NO: Replace the PCM. When the PCM is replaced, register the encrypted code. Refer to Encrypted Code Registration Criteria Table. Then go to Step 8.
STEP 8. Using scan tool MB991958, read the diagnostic trouble code (DTC).
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 P2128 set?
YES: Retry the troubleshooting.
NO: The inspection is complete.