DTC P1129: MAP Sensor Circuit Higher Than Expected
- Check for vacuum leaks in these parts:
- PCV valve
- PCV hose
- EVAP canister purge valve
- Intake manifold
- Throttle body
- Brake booster and hose
Are these any vacuum leaks?
- YES - Repair or replace the leaking part(s), then go to step 9.
- NO - Go to step 2.
- Start the engine. Hold the engine speed at 3,000 rpm without load (in Park or neutral) until the radiator fan comes on, then let it idle.
- Check the MAP SENSOR in the DATA LIST with the HDS.
Is there more than 36.9 kPa (11.0 in.Hg, 277 mmHg) or 1.1 V held for more than for 5 seconds?
- YES - Go to step 7.
- NO - Go to step 4.
- Clear the DTC with the HDS.
- Test-drive under these conditions:
- Engine coolant temperature above 158 °F (70 °C)
- A/T in D position (M/T in 5th gear)
- Maintain a vehicle speed between 55 mph (88 km/h) and 75 mph (121 km/h) for 10 seconds
- Decelerate with throttle fully closed for at least 2 seconds
- Monitor the OBD STATUS for DTC P1129 in the DTCs MENU with the HDS.
Does the screen indicate FAILED?
- YES - Go to step 7.
- NO - If the screen indicates PASSED, intermittent failure, system is OK at this time. Check for poor connections or loose terminals at the MAP sensor and the ECM/PCM. If the screen indicates NOT COMPLETED, go to step 5 and recheck.
- Turn the ignition switch OFF.
- Replace the MAP sensor (see MAP SENSOR REPLACEMENT ).
- Turn the ignition switch ON (II).
- Reset the ECM/PCM with the HDS.
- Do the ECM/PCM idle learn procedure (see ECM/PCM IDLE LEARN PROCEDURE ).
- Start the engine. Hold the engine speed at 3,000 rpm without load (in Park or neutral) until the radiator fan comes on, then let it idle.
- Test-drive under these conditions:
- Engine coolant temperature above 158 °F (70 °C)
- A/T in D position (M/T in 5th gear)
- Maintain a vehicle speed between 55 mph (88 km/h) and 75 mph (121 km/h) for 10 seconds
- Decelerate with throttle fully closed for at least 2 seconds
- Check for Temporary DTCs or DTC with the HDS.
Are any Temporary DTCs or DTCs indicated?
- YES - If DTC P1129 is indicated, check for poor connections or loose terminals at the MAP sensor and the ECM/PCM, then go to step 1. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.
- NO - Go to step 15.
- Monitor the OBD STATUS for DTC P1129 in the DTCs MENU with the HDS.
Does the screen indicate PASSED?