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 Intake manifold Brake booster Brake booster hose Are there any vacuum leaks? YES - Repair or replace parts with vacuum leaks, 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 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 (ECT SENSOR 1) above 158°F (70°C) A/T in D position (M/T in 5th gear) Drive at a steady speed between 55-75 mph (88-120 km/h) for 10 seconds During the drive, decelerate (with the 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, the 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 (ECT SENSOR 1) above 158°F (70°C) A/T in D position (M/T in 5th gear) Drive at a steady speed between 55-75 mph (88-120 km/h) for 10 seconds During the drive, decelerate (with the throttle fully closed) for at least 2 seconds
- Check for Temporary DTCs or DTCs with the HDS. Is DTC P1129 indicated? YES - Check for poor connections or loose terminals at the MAP sensor and the ECM/PCM, then go to step 1 . 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. If any other Temporary DTCs or DTCs were indicated in step 14, go to the indicated DTCs troubleshooting. 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 .