P1129

DTC P1129: MAP Sensor Signal Higher Than Expected

1. Check for vacuum leaks in these parts.
- PCV valve
- PCV hose
- EVAP canister purge valve
- Throttle body
- Brake booster hose

Are the parts OK?

YES - Go to step 2.

NO - Repair or replace leaking parts, then go to step 9.

2. Start the engine. Hold the engine speed at 3,000 rpm with no load (in Park or neutral) until the radiator fan comes on, then let it idle.
3. Check the MAP SENSOR in the DATA LIST with the HDS.

Is more than 36.9 kPa (277 mmHg, 11.0 in.Hg) or 1.1 V held for more than for 5 seconds?

YES - Go to step 7.

NO - Go to step 4.

4. Clear the DTC with the HDS.
5. Test-drive under the following conditions.
- Engine coolant temperature more than 158 °F (70 °C).
- Engine speed between 1,400 and 6,500 rpm
- A/T in D position (M/T in 5th gear).
- Vehicle speed decelerated from more than 50 mph (80 km/h) with the throttle fully closed for at least 5 seconds.

6. 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. If the screen indicates NOT COMPLETED, go to step 5 and recheck.

7. Turn the ignition switch OFF.
8. Replace the MAP sensor.
9. Turn the ignition switch ON (II).
10. Reset the ECM/PCM with the HDS.
11. Do the ECM/PCM idle learn procedure.
12. Start the engine. Hold the engine speed at 3,000 rpm with no load (in Park or neutral) until the radiator fan comes on, then let it idle.
13. Test-drive under the following conditions.
- Engine coolant temperature more than 158 °F (70 °C).
- Engine speed between 1,400 and 6,500 rpm
- A/T in D position (M/T in 5th gear)
- Vehicle speed decelerated from more than 50 mph (80 km/h) with the throttle fully closed for at least 5 seconds.

14. Check for Temporary DTCs or DTC in the DTCs MENU 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 troubleshooting.

NO - Go to step 15.

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.