Gas
P0122-THROTTLE POSITION SENSOR 1 CIRCUIT LOW
For complete wiring diagrams refer to Diagrams/Electrical.
- When Monitored:
With the ignition on. Battery voltage greater than 10 volts.
- Set Condition:
Throttle Position Sensor voltage at the PCM is less than 0.16 of a volt for 0.7 of a second. One Trip Fault. Three good trips to turn off the MIL. ETC light will illuminate.
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding.
Diagnostic Test
1. ACTIVE DTC
NOTE: If a 5-Volt Supply DTC has also set, diagnose the 5-Volt DTC before continuing.
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, select View DTCs.
Is the DTC Active at this time?
Yes
- Go To 2
No
- Go To 10
2. P0222 ALSO SET
Was the P0222-TP SENSOR NO.2 VOLTAGE LOW DTC set along with the P0122?
Yes
- Go To 3
No
- Go To 4
3. (F855) 5-VOLT SUPPLY CIRCUIT
Turn the ignition off.
Disconnect the Throttle Body harness connector.
Ignition on, engine not running.
Measure the voltage on the (F855) 5-volt Supply circuit in the Throttle Body harness connector.
Is the voltage between 4.8 to 5.2 volts?
Yes
- Go To 4
No
- Go To 7
4. THROTTLE POSITION SENSOR
With a scan tool, monitor the TP Sensor No.1 voltage with the Sensor harness connector disconnected.
Is the voltage above 4.5 volts?
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 POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
No
- Go To 5
5. (K22) TP SIGNAL 1 CIRCUIT SHORTED TO GROUND
Turn the ignition off.
Disconnect the C2 PCM harness connector.
Measure the resistance between ground and the (K22) TP Signal 1 circuit in the Throttle Body harness connector.
Is the resistance below 100 ohms?
Yes
- Repair the short to ground in the (K22) TP Signal 1 circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
No
- Go To 6
6. (K22) TP SIGNAL 1 CIRCUIT SHORTED TO THE (K922) TP RETURN CIRCUIT
Measure the resistance between the (K22) TP Signal 1 circuit and the (K922) TP Return circuit in the Throttle Body harness connector.
Is the resistance below 100 ohms?
Yes
- Repair the short between the (K922) TP Return circuit and the (K22) TP Signal 1 circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
No
- Go To 9
7. (F855) 5-VOLT SUPPLY CIRCUIT OPEN
Turn the ignition off.
Disconnect the C2 PCM harness connector.
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 diagnostics.
Measure the resistance of the (F855) 5-volt Supply circuit from the Throttle Body harness connector to the appropriate terminal of special tool #8815.
Is the resistance below 5.0 ohms?
Yes
- Go To 8
No
- Repair the open in the (F855) 5-volt Supply circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
8. (F855) 5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND
Measure the resistance between ground and the (F855) 5-volt Supply circuit in the Throttle Body harness connector.
Is the resistance below 100 ohms?
Yes
- Repair the short to ground in the (F855) 5-volt Supply circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
No
- Go To 9
9. 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
- Repair as necessary.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
No
- Replace and program the Powertrain Control Module.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
10. THROTTLE FOLLOWER TEST
With a scan tool, perform the Throttle Follower Test.
Monitor the TP Sensor No.1 voltage.
Does voltage start at approximately 0.8 of a volt and go above 3.5 volts with a smooth transition?
Yes
- Refer to the INTERMITTENT CONDITION Diagnostic Procedure. Intermittent Condition
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
No
- Disconnect the Battery when replacing the Throttle Body Assembly. Replace the Throttle Body Assembly. After installation is complete, using a scan tool select ETC RELEARN function.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test