DTC P1121: Throttle Position (TP) Sensor: Condition

This code indicates TP signal is inconsistent with MAF sensor signal. Possible causes for this fault are as follows:

• TP sensor not seated correctly.
• Faulty TP sensor.
• Air leak between MAF sensor and throttle body.

Normal range of throttle angle measurement for TP sensor is 0-85 degrees. To pass quick test procedure, range of throttle rotation (in degrees) must be within 3 percent of specification.

1. Check Freeze Frame Data
   
   Ensure freeze frame data is recorded. Go to next step.
2. Rationality Check
   
   Start engine. If engine starts, go to next step. If engine does not start, check for major leaks, cracks, and openings between MAF sensor and throttle body.
3. Check Operation Of TP Sensor
   
   Turn ignition on. Connect scan tool to DLC. Access TP V PID. Move throttle from closed to fully open slowly. If TP V PID changes smoothly, go to next step. If TP V PID drops suddenly during movement, check TP sensor. See appropriate SYSTEM & COMPONENT TESTING article. Repair as necessary.
4. Check TP Sensor High With Engine Under Load
   
   Drive vehicle while accessing TP PID and LOAD PID. If TP PID is 2.44 volts or less and LOAD PID is greater than 25 percent, go to next step. If TP PID is greater than 2.44 volts and LOAD PID is less than 25 percent, check for cracks or openings in air induction system between MAF sensor and throttle body. If air induction system is okay, replace TP sensor.
5. Check TP Sensor Low At Idle
   
   Start engine and allow to idle. Access TP PID and LOAD PID on scan tool. If TP PID is 0.24 volt or more and LOAD PID is less than 60 percent, go to next step. If TP PID is less than 0.24 volts and LOAD PID is 60 percent or more, check TP sensor installation. Tighten as necessary and go to step  7.
6. Check TP Sensor Low With Engine Under Load
   
   Drive vehicle while accessing TP PID and LOAD PID. If TP PID is 0.24 volts or less and LOAD PID is greater than 60 percent, check TP sensor installation. Tighten as necessary and go to next step. If TP PID is greater than 0.24 volts and LOAD PID is less than 60 percent, fault is intermittent and cannot be located at this time. See appropriate TROUBLESHOOTING - NO CODES article.
7. Erase DTC From Memory
   
   Clear PCM memory. Perform test drive utilizing all phases of vehicle operation. Perform QUICK TEST. See SELF-DIAGNOSTICS - INTRODUCTION - 626 article. If sent from step 5)  or 6)  and DTC P1121 is still present, replace MAF sensor. If sent from step 4)  and DTC P1121 is still present, replace PCM. After repair, go to next step.
8. Recheck DTC
   
   If any DTCs are present, go to appropriate test for repair. If no DTCs are present, test is complete.