P1790

DTC P1790: Problem in Throttle Position Sensor Circuit
ULEV Model

NOTE: Record all freeze data and review General Troubleshooting Information before you troubleshoot.

1. Check whether the scan tool or the HDS indicates a code for the throttle position (TP) sensor in the fuel and emissions system.
Does the scan tool or the HDS indicate a code for TP sensor?
YES- Do the DTC Troubleshooting for the TP sensor circuit. Recheck for DTC P1790 after troubleshooting.
NO- Go to step 2.
2. Turn the ignition switch OFF.
3. Disconnect TCM connectors A (31P) and C (17P).
4. Turn the ignition switch ON (II).





5. Measure the voltage between TCM connector terminals C14 and A23 or A24.
Is there about 5 V?
YES- Go to step 6.
NO- Repair open or short in VREF wire between TCM connector terminal C14 and the ECM.
6. Close the throttle fully.





7. Measure the voltage between TCM connector terminals C9 and A23 or A24.
Is there 0.44 - 0.56 V?
YES- Check the terminal fit at TCM connector terminal C9. If the connection is OK, update the TCM if it does not have the latest software, or substitute a known-good TCM, then recheck. If the symptom/indication goes away with a known-good TCM, replace the original TCM.
NO- Repair open in the wire between TCM connector terminal C9 and the TP sensor.