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 voltage supplies power to the TAC processor independent of the ECM processor. The ECM compares the reported voltage from the TAC processor to the ignition voltage supplied to the ECM processor. If the voltages are not within a specified range of each other the ECM will set this DTC.

CONDITIONS FOR RUNNING THE DTC
- The ignition is in the Run, or Crank.
- DTC P1682 runs continuously when the ignition is in Run or Crank.

CONDITIONS FOR SETTING THE DTC
The ignition 1voltage from the Run/Crank relay is more than 3 volts different from the ignition 1voltage from the powertrain relay 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. 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 illuminates 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
Control Module References for ECM replacement, setup, and programming.

REPAIR VERIFICATION
Always perform the Diagnostic Repair Verification after completing the diagnostic procedure. Verification Tests