Ford DTC P1129 – Heated Oxygen Sensor Signals reversed
DTC P1129 meaning on Ford
DTC P1129 on a Ford vehicle indicates that the heated oxygen sensor (HO2S) signals are reversed. This means that the oxygen sensor is sending incorrect signals to the engine control module (ECM), causing potential issues with fuel mixture control.
Ford DTC P1129 symptoms
- Check Engine Light (CEL) illuminated
- Decreased fuel efficiency
- Engine running rough or misfiring
- Increased emissions
Ford DTC P1129 causes
- Faulty heated oxygen sensor (HO2S)
- Wiring issues or short circuits in the oxygen sensor circuit
- ECM malfunction
Ford DTC P1129 seriousness
The seriousness of DTC P1129 on a Ford vehicle lies in its impact on fuel efficiency, emissions, and overall engine performance. Ignoring this issue can lead to further damage to the engine and catalytic converter.
How to diagnose DTC P1129 on Ford
- Use an OBD-II scanner to retrieve the trouble codes
- Inspect the wiring and connectors of the heated oxygen sensor
- Check the HO2S for proper operation
- Perform a visual inspection for any visible damage
How to fix DTC P1129 on Ford
- Replace the faulty heated oxygen sensor (HO2S)
- Repair any damaged wiring or connectors in the oxygen sensor circuit
- If necessary, replace the ECM
How to erase DTC P1129 on Ford
- Use an OBD-II scanner to clear the trouble codes
- Ensure the issue has been resolved before clearing the codes
- Drive the vehicle to allow the ECM to relearn the sensor signals
Recommended tools for Ford diagnostics
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