P1682

DTC P1682

DTC DESCRIPTOR

DTC P1682
Ignition 1 Switch Circuit 2

DIAGNOSTIC FAULT INFORMATION

IMPORTANT: Always perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Testing and Inspection






CIRCUIT/SYSTEM DESCRIPTION
The Throttle Actuator Control (TAC) System uses an ignition voltage supply separate from the engine control module (ECM) supply.

CONDITIONS FOR RUNNING THE DTC
- The ignition is ON.
- DTC P1682 runs continuously when the ignition is ON.

CONDITIONS FOR SETTING THE DTC
The ignition 1 voltage is less than 10 volts for more than 2 seconds.

ACTION TAKEN WHEN THE DTC SETS
- The control module illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails.
- The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Freeze Frame and/or the Failure Records.
- The control module commands the TAC system to operate in the Reduced Engine Power mode.
- A message center or an indicator displays Reduced Engine Power.
- Under certain conditions the control module commands the engine OFF.

CONDITIONS FOR CLEARING THE MIL/DTC
- The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
- A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
- A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
- Clear the MIL and the DTC with a scan tool.

CIRCUIT/SYSTEM VERIFICATION
Ignition ON, observe the Ignition 1 Voltage parameter. Voltage should be more than 10 volts.

CIRCUIT/SYSTEM TESTING
1. Ignition ON, observe the Ignition 1 Voltage parameter. Voltage should be more than 10 volts.
- If less than 10 volts, test the ignition 1 voltage circuit that powers the ETC fuse for an open or a faulty ECM.
2. Ignition ON, probe both sides of the ETC fuse with a test lamp. The test lamp should illuminate on both sides of the fuse.
- If the test lamp illuminates on only one side of the fuse, test the ignition 1 voltage circuit that powers the ETC fuse for a short to ground or a faulty ECM.
3. Ignition OFF, probe both sides of the ETC fuse. The test lamp should not illuminate on either side of the fuse.
- If the test lamp illuminates on at least one side of the fuse, test the ignition 1 voltage circuit that powers the ETC fuse for a short to voltage or a faulty ECM.
4. Ignition ON, probe both sides of the PCM IGN 1 fuse. The test lamp should illuminate on both sides of the fuse.
- If the test lamp illuminates on only one side of the fuse test the ignition 1 voltage circuit that powers the PCM IGN 1 fuse for a short to ground or a faulty ECM.
- If the test lamp does not illuminate on both sides of the fuse, test the ignition 1 voltage circuit that powers the PCM IGN 1 fuse for an open or faulty ECM.
5. Ignition OFF, probe both sides of the PCM IGN 1 fuse. The test lamp should not illuminate on either side of the fuse.
- If the test lamp illuminates on at least one side of the fuse, test the ignition 1 voltage circuit that powers the PCM IGN 1 fuse for a short to voltage or a faulty ECM.

REPAIR INSTRUCTIONS

IMPORTANT: Always perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for ECM replacement, setup, and programming