P2123-ACCELERATOR PEDAL POSITION SENSOR 1 CIRCUIT HIGH
For a complete wiring diagram Refer to Section 8W.
-
When Monitored:
With the ignition on and no other APPS No.1 DTCs present.
-
Set Condition:
When APP Sensor No.1 voltage is too high. Engine will additionally idle if the brake pedal is pressed or has 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
|
(K23) APP SIGNAL 1 CIRCUIT SHORTED TO BATTERY VOLTAGE
|
(K23) APP SIGNAL 1 SHORTED TO THE (F855) 5-VOLT SUPPLY CIRCUIT
|
(K23) APP SIGNAL 1 SHORTED TO THE (F856) 5-VOLT SUPPLY CIRCUIT
|
(K167) APP RETURN 1 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.1 VOLTAGE ABOVE 4.8 VOLTS
NOTE:
When this DTC is Active the engine speed, torque, and vehicle speed are limited to a Limp in mode.
Ignition on, engine not running.
With a scan tool, read the APP Sensor No.1 voltage.
Is the voltage above 4.8 volts?
Yes
No
2.
ACCELERATOR PEDAL POSITION SENSOR
Turn the Ignition off.
Disconnect the APP Sensor harness connector.
Ignition on, engine not running.
With a scan tool, monitor the Accelerator Pedal Position Sensor voltage.
Is the voltage above 0 volts?
Yes
No
-
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.
(K23) APP SIGNAL 1 CIRCUIT SHORTED TO BATTERY VOLTAGE
Turn the ignition off.
Disconnect the C1, C2, and C3 PCM harness connectors.
Ignition on, engine not running.
Measure the voltage on the (K23) APP Signal 1 circuit in the APP Sensor harness connector.
Is the voltage above 0 volts?
Yes
No
4.
(K23) APP SIGNAL 1 CIRCUIT SHORTED TO THE (F855) 5-VOLT SUPPLY CIRCUIT
Turn the ignition off.
Measure the resistance between the (K23) APP Signal 1 circuit and the (F855) 5-volt Supply circuit in the APP Sensor harness connector.
Is the resistance below 100 ohms?
Yes
No
5.
(K23) APP SIGNAL 1 CIRCUIT SHORTED TO THE (F856) 5-VOLT SUPPLY CIRCUIT
Measure the resistance between the (K23) APP Signal 1 circuit and the (F856) 5-volt Supply circuit in the APP Sensor harness connector.
Is the resistance below 100 ohms?
Yes
No
6.
(K167) APP RETURN 1 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.
Measure the resistance of the (K167) APP Return 1 circuit from the APP Sensor harness connector to the appropriate terminal of special tool #8815.
Is the resistance below 5.0 ohms?
Yes
No
7.
PCM
NOTE:
Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal push out. Repair as necessary.
Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and Ground circuits.
Were there any problems found?
Yes
No
8.
APP SENSOR NO.1 SWEEP
Ignition on, engine not running.
With a scan tool, monitor the Accelerator Pedal Position Sensor voltage.
Slowly press the Accelerator Pedal down.
Does voltage start at approximately 0.45 of a volt and go above 4.6 volts with a smooth transition?
Yes
No
-
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)