DTC Troubleshooting: P2127 (37-12)

DTC P2127:  APP Sensor B Circuit Low Voltage

1.Turn the ignition switch ON (II).

2.Check APP SENSOR B in the DATA LIST with the HDS.

Is there about 0.097 V or less?


YES - Go to 3.


NO - Intermittent failure, system is OK at this time. Check for poor connections or loose terminals at the APP sensor and the ECM.n


3.Turn the ignition switch OFF.

4.Disconnect the APP sensor 6P connector.

5.Turn the ignition switch ON (II).

6.Measure voltage between APP sensor 6P connector terminals No. 1 and No. 2.

 

Is there about 5 V?


YES - Go to 7.


NO - Go to 14.

7.Turn the ignition switch OFF.

8.At sensor side, measure resistance between APP sensor 6P connector terminals No. 2 and No. 3 with the throttle fully closed.

 

Is there about 0.35-0.45 kW at room temperature?


YES - Go to 9.


NO - Go to 18.


9.At sensor side, measure resistance between APP sensor 6P connector terminals No. 1 and No. 3 with the throttle fully closed.

 

Is there about 5.6-6.8 kW at room temperature?


YES - Go to 10.


NO - Go to 18.

10.Disconnect ECM connector No. 2 (58P).

11.Check for continuity between ECM connector No. 2 terminal No. 9 and body ground.

 

Is there continuity?


YES - Repair short in the wire between the APP sensor and ECM connector No. 2 terminal No. 9, then go to 20.


NO - Go to 12.


12.Connect APP sensor 6P connector terminal No. 3 to body ground with a jumper wire.

 

13.Check for continuity between ECM connector No. 2 terminal No. 9 and body ground.

 

Is there continuity?


YES - Go to 24.


NO - Repair open in the wire between the APP sensor and ECM connector No. 2 terminal No. 9, then go to 20.


14.Turn the ignition switch OFF, and wait 30 seconds.

15.Disconnect ECM connector No. 2 (58P).

16.Connect APP sensor 6P connector terminal No. 1 to body ground with a jumper wire.

 

17.Check for continuity between ECM connector No. 2 terminal No. 13 and body ground.

 

Is there continuity?


YES - Go to 24.


NO - Repair open in the wire between the APP sensor and ECM connector No. 2 terminal No. 13, then go to 20.


18.Turn the ignition switch OFF.

19.Replace the APP sensor.

20.Reconnect all connectors.

21.Turn the ignition switch ON (II).

22.Reset the ECM with the HDS.

23.Check for Temporary DTCs or DTCs with the HDS.

Are any Temporary DTCs or DTCs indicated?


YES - If DTC P2127 is indicated, check for poor connections or loose terminals at the APP sensor and the ECM, then go to 1. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.


NO - Troubleshooting is complete.n

24.Update the ECM if it does not have the latest software, or substitute a known-good ECM.

25.Check for Temporary DTCs or DTCs with the HDS.

Are any Temporary DTCs or DTCs indicated?


YES - If DTC P2127 is indicated, check for poor connections or loose terminals at the APP sensor and the ECM, then go to 1. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.


NO - If the ECM was updated, troubleshooting is complete. If the ECM was substituted, replace the original ECM.n