16505
From Ross-Tech Wiki
16505/P0121 - Throttle Position Sensor (G69): Implausible Signal
Possible Symptoms
- MIL on
- Poor engine performance
Possible Causes
- Wiring Harness issue
- Failed Throttle Body
- Failed ECM
Possible Solutions
- Test wiring as per Factory Repair Manual
Special Notes
- For some vehicles, there may be a TPI with instructions on replacing the terminals for the throttle body.
- Some ECMs may have a firmware update to address this issue during cold weather.
- The component identifier G69 may be G187 per the wiring diagrams for the vehicle in question.