DTC Troubleshooting: P2127 (37)
DTC P2127:
 APP Sensor B (Throttle Position Sensor E) Circuit Low Voltage
NOTE: Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information.
  1. Turn the ignition switch ON (II).
  1. Check APP SENSOR B in the DATA LIST with the HDS.
Is there about 0.2 V or less?
YES -
Go to Step 3 .
NO -
Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at APP sensor B and the ECM.■
  1. Turn the ignition switch OFF.
  1. Disconnect the APP sensor 6P connector.
  1. Turn the ignition switch ON (II).
  1. Measure voltage between APP sensor 6P connector terminals No. 5 and No. 6.
Is there about 5 V?
YES -
Go to Step 7 .
NO -
Go to Step 18 .
  1. Turn the ignition switch OFF.
  1. Jump the SCS line with the HDS.
  1. Disconnect ECM connector A (44P).
  1. Check for continuity between APP sensor 6P connector terminal No. 4 and body ground.
Is there continuity?
YES -
Repair short in the wire between the ECM (A18) and APP sensor B, then go to Step 25 .
NO -
Go to Step 11 .
  1. Connect APP sensor 6P connector terminal No. 4 to body ground with a jumper wire.
  1. Check for continuity between ECM connector terminal A18 and body ground.
Is there continuity?
YES -
Go to Step 13 .
NO -
Repair open in the wire between the ECM (A18) and APP sensor B, then go to Step 25 .
  1. Reconnect ECM connector A (44P).
  1. Connect a battery.
  1. Connect APP sensor 6P connector terminals No. 4 and No. 6 with a jumper wire.
  1. Turn the ignition switch ON (II).
  1. Check APP SENSOR B in the DATA LIST with the HDS.
Is there about 0.2 V or less?
YES -
Go to Step 30 .
NO -
Go to Step 23 .
  1. Turn the ignition switch OFF.
  1. Jump the SCS line with the HDS.
  1. Disconnect ECM connector A (44P).
  1. Connect APP sensor 6P connector terminal No. 6 to body ground with a jumper wire.
  1. Check for continuity between ECM connector terminal A24 and body ground.
Is there continuity?
YES -
Go to Step 30 .
NO -
Repair open in the wire between the ECM (A24) and APP sensor B, then go to Step 25 .
  1. Turn the ignition switch OFF.
  1. Reconnect all connectors and the battery.
  1. Turn the ignition switch ON (II).
  1. Reset the ECM with the HDS.
  1. Check for Temporary DTCs or DTCs with the HDS.
Is DTC P2127 indicated?
YES -
Check for poor connections or loose terminals at APP sensor B and the ECM, then go to Step 1 .
NO -
Troubleshooting is complete. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.■
  1. Reconnect all connectors.
  1. Check for Temporary DTCs or DTCs with the HDS.
Is DTC P2127 indicated?
YES -
Check for poor connections or loose terminals at APP sensor B and the ECM. If the ECM was updated, substitute a known-good ECM, then recheck. If the ECM was substituted, go to Step 1 .
NO -
If the ECM was updated, troubleshooting is complete. If the ECM was substituted, replace the original ECM. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.■