Note. Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ).
- Check for vacuum leaks in these parts: PCV valve PCV hose EVAP canister purge valve Throttle body Brake booster and hose Are there any vacuum leaks? YES- Repair or replace leaking parts, 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 5 seconds? YES- Go to step 7 . NO- Go to step 4 .
- Clear the DTC with the HDS.
- Test-drive under these conditions: ECT SENSOR above 158°F (70°C) Engine speed between 1,400 and 5,700 RPM A/T in D position (M/T in 5th gear) Maintain a vehicle speed of 55-75 mph (88 - 121 km/h) for 10 seconds Decelate 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»(ref-220570-S17955277902006022000000) ).
- 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»(ref-220572-S08440202922006022000000) ).
- 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: ECT SENSOR above 158°F (70°C) Engine speed between 1,400 and 5,700 RPM A/T in D position (M/T in 5th gear) Maintain a vehicle speed of 55-75 mph (88-121 km/h) for 10 seconds Decelate 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? YES- Troubleshooting is complete. NO- If the screen indicates FAILED, check for poor connections or loose terminals at the MAP sensor and the ECM/PCM, then go to step 1 . If the screen indicates NOT COMPLETED, go to step 12 and recheck.