P2128-ACCELERATOR PEDAL POSITION SENSOR 2 CIRCUIT HIGH

For a complete wiring diagram Refer to Section 8W.

When Monitored:
With the ignition on and no other APPS No.2 DTCs present.
Set Condition:
When APP Sensor No.2 voltage is too high. Idle is additionally forced any time the brake is applied or failed. Acceleration rate and Engine output are limited. One trip fault and the code will set within 5 seconds. ETC light is flashing.

Possible Causes

(K29) APP SENSOR NO.2 SIGNAL CIRCUIT SHORTED TO BATTERY VOLTAGE

(K29) APP SENSOR NO.2 SIGNAL SHORTED TO THE (F856) 5-VOLT SUPPLY CIRCUIT

(K29) APP SENSOR NO.2 SIGNAL SHORTED TO THE (F855) 5-VOLT SUPPLY CIRCUIT

(K400) APP SENSOR NO.2 RETURN CIRCUIT OPEN

APP SENSOR

PCM

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).

Diagnostic Test

1.APPS NO.2 VOLTAGE ABOVE 3.0 VOLTS

NOTE: When this DTC is Active the engine speed, torque, and vehicle speed are limited to a Limp in mode.

NOTE: Diagnose any 5-Volt Supply DTCs before continuing.

Is the voltage above 3.0 volts?

Yes

Go To 2

Go To 8

2.ACCELERATOR PEDAL POSITION SENSOR

Is the voltage above 0 volts?

Yes

Go To 3

Replace the APP Sensor Assembly per Service Information. After installation is complete, use a scan tool and select the ETC RELEARN function to relearn the APPS values.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

3.(K29) APP SENSOR NO.2 SIGNAL CIRCUIT SHORTED TO BATTERY VOLTAGE

Is the voltage above 0 volts?

Yes

Repair the short to battery voltage in the (K29) APP Sensor No.2 Signal circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

Go To 4

4.(K29) APPS NO.2 SIGNAL CIRCUIT SHORTED TO THE (F856) 5-VOLT SUPPLY CIRCUIT

Is the resistance below 10 ohms?

Yes

Repair the short between the (K29) APP Sensor No.2 Signal circuit and the (F856) 5-volt Supply circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

Go To 5

5.(K29) APPS NO.2 SIGNAL CIRCUIT SHORTED TO THE (F855) 5-VOLT SUPPLY CIRCUIT

Is the resistance below 10 ohms?

Yes

Repair the short between the (K29) APP Sensor No.2 Signal circuit and the (F855) 5-volt Supply circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

Go To 6

6.(K400) APP SENSOR NO.2 RETURN CIRCUIT OPEN

CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install Miller Special Tool #8815 to perform diagnosis.

Is the resistance below 5.0 ohms?

Yes

Go To 7

Repair the open in the (K400) APP Sensor No.2 Return circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

7.PCM

NOTE: Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal push out. Repair as necessary.

Were there any problems found?

Yes

Repair as necessary.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

Replace and program the Powertrain Control Module per Service Information.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

8.APP SENSOR NO.2 SWEEP

Does voltage start at approximately 0.22 of a volt and go above 2.31 volts with a smooth transition?

Yes

Refer to the INTERMITTENT CONDITION Diagnostic Procedure.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

Replace the APP Sensor Assembly per Service Information. After installation is complete, use a scan tool and select the ETC RELEARN function to relearn the APPS values.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)