P0123
P0123-THROTTLE POSITION SENSOR 1 CIRCUIT HIGH
- When Monitored:
With the ignition on. Battery voltage greater than 10 volts.
- Set Condition:
Throttle Position Sensor No.1 voltage is greater than maximum acceptable value. One Trip Fault. ETC light will flash.
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Pre-Diagnostic Troubleshooting Procedure.
1. ACTIVE DTC
NOTE: Diagnose and repair any Throttle Body circuit, system voltage, or sensor supply voltage DTCs before continuing with this test.
1. Start the engine and allow it to reach operating temperature.
WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury.
2. With the scan tool select View DTCs.
NOTE: If the DTC does not reset it may be necessary to test drive the vehicle.
Is the DTC Active at this time?
Yes
- Go To 2
No
- Go To 8
2. THROTTLE POSITION SENSOR
1. Turn the ignition off.
2. Disconnect the Throttle Body 1 harness connector.
3. Connect a jumper wire between the (K22) TP 1 Signal 1 circuit and the (K922) TP 1 Sensor Ground circuit in the Throttle Body harness connector.
4. With a scan tool, monitor the TP Sensor 1 voltage.
5. Ignition on, engine not running.
NOTE: The sensor voltage should be approximately 0.0 volts (plus or minus.1 volt) with the jumper wire in place.
Does the scan tool display the voltage as described above?
Yes
- 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.
- Perform the PCM Verification Test. PCM Verification Test.
No
- Go To 3 NOTE: Remove the jumper wire before continuing.
3. (K22) TP 1 SIGNAL 1 CIRCUIT SHORTED TO VOLTAGE
1. Turn the ignition off.
2. Disconnect the C2 PCM harness connector.
3. Ignition on, engine not running.
4. Measure the voltage on the (K22) TP 1 Signal 1 circuit in the Throttle Body 1 harness connector.
Is there any voltage present?
Yes
- Repair the short to voltage in the (K22) TP 1 Signal 1 circuit.
- Perform the PCM Verification Test. PCM Verification Test.
No
- Go To 4
4. (K22) TP 1 SIGNAL 1 CIRCUIT OPEN
1. Turn the ignition off.
2. Measure the resistance of the (K22) TP 1 Signal 1 circuit from the Throttle Body 1 harness connector to the C2 PCM harness connector.
Is the resistance below 5.0 ohms?
Yes
- Go To 5
No
- Repair the open in the (K22) TP 1 Signal 1 circuit.
- Perform the PCM Verification Test. PCM Verification Test.
5. (K22) TP 1 SIGNAL 1 CIRCUIT SHORTED TO THE (F855) 5-VOLT SUPPLY CIRCUIT
1. Measure the resistance between the (K22) TP 1 Signal 1 circuit and the (F855) 5-volt Supply circuit in the Throttle Body 1 harness connector.
Is the resistance below 100 ohms?
Yes
- Repair the short between the (F855) 5-volt Supply circuit and the (K22) TP 1 Signal 1 circuit.
- Perform the PCM Verification Test. PCM Verification Test.
No
- Go To 6
6. (K922) TP 1 SENSOR GROUND CIRCUIT OPEN
1. Measure the resistance of the (K922) TP 1 Sensor Ground circuit from the Throttle Body 1 harness connector to the C2 PCM harness connector.
Is the resistance below 5.0 ohms?
Yes
- Go To 7
No
- Repair the open in the (K922) TP 1 Sensor Ground circuit.
- Perform the PCM Verification Test. PCM Verification Test.
7. POWERTRAIN CONTROL MODULE (PCM)
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Throttle Body and the Powertrain Control Module (PCM).
2. Look for any chafed, pierced, pinched, or partially broken wires.
3. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the Throttle Body and Powertrain Control Module connectors.
4. Search for any Technical Service Bulletins that may apply.
Were there any problems found?
Yes
- Repair as necessary.
- Perform the PCM Verification Test. PCM Verification Test.
No
- Replace and program the Powertrain Control Module.
- Perform the PCM Verification Test. PCM Verification Test.
8. THROTTLE FOLLOWER TEST
1. Ignition on, engine not running.
2. With a scan tool, perform the ETC Throttle Follower Test.
3. Monitor the TP Sensor 1 voltage while slowly pressing the accelerator pedal down.
Does the voltage transition smoothly between the approximate range of 0.55V and 4.3V?
Yes
- Refer to the INTERMITTENT CONDITION Diagnostic Procedure. Checking for an Intermittent DTC.
No
- 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.
- Perform the PCM Verification Test. PCM Verification Test.