P1121 FORD F150 Possible Causes
- Air leak between the mass air flow sensor and throttle body
- Faulty throttle position sensor
- Throttle position sensor harness is open or shorted
- Poor electrical connection in throttle position sensor circuit
- Damaged mass air flow sensor
How to Fix P1121 FORD F150 Code?
Start by checking the “possible causes” listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector pins.
When is the Code Detected?
The sensor signal output is not consistent with engine load measurement
Possible Symptoms
Check engine light on (or service engine soon warning light)
P1121 FORD F150 Meaning
The Powertrain Control Module (PCM) monitors a vehicle operation rationality check by comparing detected throttle position to mass air flow readings. If during engine running self-test, the comparison of TP sensor and MAF sensor readings is not consistent with calibrated load values, the test fails and a diagnostic code is stored in keep alive memory.