Diagnostic Test

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

NOTE: Make sure the throttle is fully closed and free from binding or carbon build up.

NOTE: If a 5-Volt Supply DTC has also set, diagnose the 5-Volt DTC before continuing.

NOTE: If P2101 is also set, then make sure that the blade moves freely and does not hang up near Wide Open Throttle before trying to repair P0123.

Start the engine and allow it to reach operating temperature.

With the scan tool select View DTCs.

NOTE: If the DTC does not reset it may be necessary to test drive the vehicle.

NOTE: If the P2123-APP Sensor 1 Circuit High DTC is also Active, diagnose the P2123 before continuing with the P0123 diagnostic procedure.

Is the DTC Active at this time?

Yes
1. Go to 2).
No
1. Go to 8).
2) THROTTLE POSITION SENSOR

Fig 1: Connecting Jumper Wire Between Sensor Return Circuit And TP Sensor No. 1 Signal Circuit
Courtesy of CHRYSLER LLC

Turn the ignition off.

Disconnect the Throttle Body harness connector.

Connect a jumper wire between the (K22) TP Sensor No. 1 Signal circuit and the (K922) Sensor Return circuit in the Throttle Body harness connector.

With a scan tool, monitor the TP Sensor No. 1 voltage.

Ignition on, engine not running.

Is the voltage below 0.5 of a volt with the jumper wire installed?

Yes
1. Disconnect the Battery when replacing the Throttle Body Assembly. Replace the Throttle Body Assembly. After installation is complete, using a scan tool, select the ETC RELEARN function.
2. Perform POWERTRAIN VERIFICATION TEST .
No
1. Go to 3).
  NOTE: Remove the jumper wire before continuing.
3) (K22) TP SENSOR NO. 1 SIGNAL CIRCUIT SHORTED TO BATTERY VOLTAGE

Fig 2: Checking TP Sensor No. 1 Signal Circuit For Short To Voltage
Courtesy of CHRYSLER LLC

Turn the ignition off.

Disconnect the C2 PCM harness connector.

Ignition on, engine not running.

Measure the voltage on the (K22) TP Sensor No. 1 Signal circuit in the Throttle Body harness connector.

Is the voltage above 0 volts?

Yes
1. Repair the short to battery voltage in the (K22) TP Sensor No. 1 Signal circuit.
2. Perform POWERTRAIN VERIFICATION TEST .
No
1. Go to 4).
4) (K22) TP SENSOR NO. 1 SIGNAL CIRCUIT OPEN

Fig 3: Checking TP Sensor No. 1 Signal Circuit For Open Or Excessive Resistance
Courtesy of CHRYSLER LLC

Turn the ignition off.

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 (K22) TP Sensor No. 1 Signal circuit from the Throttle Body harness connector to the appropriate terminal of special tool #8815.

Is the resistance below 5.0 ohms?

Yes
1. Go to 5).
No
1. Repair the open in the (K22) TP Sensor No. 1 Signal circuit.
2. Perform POWERTRAIN VERIFICATION TEST .
5) (K22) TP SENSOR NO. 1 SIGNAL CIRCUIT SHORTED TO THE (F855) 5-VOLT SUPPLY CIRCUIT

Fig 4: Checking TP Sensor No. 1 Signal Circuit For Short To 5-Volt Supply Circuit
Courtesy of CHRYSLER LLC

Measure the resistance between the (K22) TP Sensor No. 1 Signal circuit and the (F855) 5-volt Supply circuit in the Throttle Body harness connector.

Is the resistance below 100 ohms?

Yes
1. Repair the short between the (F855) 5-volt Supply circuit and the (K22) TP Sensor No. 1 Signal circuit.
2. Perform POWERTRAIN VERIFICATION TEST .
No
1. Go to 6).
6) (K922) SENSOR RETURN CIRCUIT OPEN

Fig 5: Checking Sensor Return Circuit For Open
Courtesy of CHRYSLER LLC

Measure the resistance of the (K922) Sensor Return circuit from the Throttle Body harness connector to the appropriate terminal of special tool #8815.

Is the resistance below 5.0 ohms?

Yes
1. Go to 7).
No
1. Repair the open in the (K922) Sensor Return circuit.
2. Perform POWERTRAIN VERIFICATION TEST .
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
1. Repair as necessary.
2. Perform POWERTRAIN VERIFICATION TEST .
No
1. Replace and program the Powertrain Control Module per Service Information.
2. Perform POWERTRAIN VERIFICATION TEST .
8) THROTTLE FOLLOWER TEST
With a scan tool, perform the Throttle Follower Test.

Monitor the TP Sensor No. 1 voltage.

Does voltage start at approximately 0.3 of a volt and go above 4.7 volts with a smooth transition?

Yes
1. Refer to INTERMITTENT CONDITION Diagnostic Procedure.
No
1. Disconnect the Battery when replacing the Throttle Body Assembly. Replace the Throttle Body Assembly. After installation is complete, using a scan tool select the ETC RELEARN function.
2. Perform POWERTRAIN VERIFICATION TEST .