DTC Troubleshooting

DTC Troubleshooting: P1129 (5)

DTC P1129:

MAP Sensor Signal Higher Than Expected

NOTE: Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information Initial Inspection and Diagnostic Overview.

1. Check for vacuum or air leaks in these parts:

- PCV valve
- PCV hose
- EVAP canister purge valve
- Throttle body
- Air bypass outlet pipe
- Intake manifold
- Brake booster
- Brake booster hose
- Fuel pressure regulator
- Turbocharger
- Charge air cooler
- Intake air duct (turbocharger inlet tube and pipe)
- Intake air duct (turbocharger outlet pipe)
- Intake air duct (charge air cooler inlet hose)
- Intake air duct (charge air cooler outlet tube)
- Turbocharger bypass control solenoid valve

Are there any vacuum or air leaks?

YES -

Repair or replace part(s) with vacuum or air leaks, then go to step 9.

NO -

Go to step 2.

2. Turn the ignition switch to ON (II).

3. Compare the value of the MAP SENSOR and the TURBOCHARGER BOOST SENSOR in the DATA LIST with the HDS.

Does the value differ more than 26.7 kPa (7.9 inHg, 200 mmHg)?

YES -

Go to step 11.

NO -

Go to step 4.

4. Note the value of MAP SENSOR in the DATA LIST with the HDS.

5. Start the engine, and let it idle.

6. Check the MAP SENSOR in the DATA LIST with the HDS.

Does the MAP SENSOR change 0.67 kPa (0.2 inHg, 5 mmHg) or more?

YES -

Go to step 7.

NO -

Go to step 11.

7. Clear the DTC with the HDS.

8. Start the engine. Hold the engine speed at 3,000 rpm without load (in P or N) until the radiator fan comes on, then let it idle.

9. Test-drive under these conditions:

- Engine speed above 1,750 rpm
- Transmission in D
- REL TP SENSOR above 22 deg
- Drive 5 seconds or more

10. Monitor the OBD STATUS for DTC P1129 in the DTCs MENU with the HDS.

Does the HDS indicate FAILED?

YES -

Go to step 1.

NO -

If the HDS indicates PASSED, intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the MAP sensor and the PCM. If the HDS indicates NOT COMPLETED, go to step 8 and recheck.

11. Turn the ignition switch to LOCK (0).

12. Replace the MAP sensor Service and Repair.

13. Turn the ignition switch to ON (II).

14. Reset the PCM with the HDS.

15. Do the PCM idle learn procedure PCM Idle Learn Procedure.

16. Start the engine. Hold the engine speed at 3,000 rpm without load (in P or N) until the radiator fan comes on, then let it idle.

17. Test-drive under these conditions:

- Engine speed above 1,750 rpm
- Transmission in D
- REL TP SENSOR above 22 deg
- Drive 5 seconds or more

18. Check for Pending or Confirmed DTCs with the HDS.

Is DTC P1129 indicated?

YES -

Check for poor connections or loose terminals at the MAP sensor and the PCM, then go to step 1.

NO -

Go to step 19.

19. Monitor the OBD STATUS for DTC P1129 in the DTCs MENU with the HDS.

Does the HDS indicate PASSED?

YES -

Troubleshooting is complete. If any other Pending or Confirmed DTCs were indicated in step 18, go to the indicated DTC's troubleshooting.

NO -

If the HDS indicates FAILED, check for poor connections or loose terminals at the MAP sensor and the PCM, then go to step 1. If the HDS indicates NOT COMPLETED, go to step 16.