P1682
DTC P1682
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) provides an overview of each of the diagnostic category.
DTC Descriptor
DTC P1682
- Ignition 1 Switch Circuit 2
Diagnostic Fault Information
Typical Scan Tool Data
Circuit/System Description
There are 2 ignition 1 voltage circuits supplied to the engine control module (ECM). The first ignition 1 voltage circuit is provided by the powertrain relay, through a fuse. This ignition 1 voltage circuit supplies power to all the internal ECM circuits associated with the throttle actuator control (TAC) operation. The run/crank relay provides the second ignition 1 voltage circuit to the ECM, through a fuse. This ignition 1 voltage provides power to other internal ECM circuits, except those associated with TAC operation. The ECM continuously monitors the voltage level difference between the two circuits.
Conditions for Running the DTC
* The ignition is in the Unlock/Accessory, Run, or Crank position.
* System voltage is more than 5.23V.
* Powertrain relay is commanded ON
* DTC P1682 runs continuously when the above conditions are met.
Conditions for Setting the DTC
The ignition 1 voltage of the Run/Crank relay is more than 3 volts different than the ignition 1 voltage of the powertrain relay for more than 2 seconds.
Action Taken When the DTC Sets
DTC P1682 is a Type B DTC.
Engine may operate in a reduced engine power mode.
Conditions for Clearing the DTC
DTC P1682 is a Type B DTC.
Diagnostic Aids
This test procedure requires that the vehicle battery has passed a load test and is completely charged. Refer to Battery Inspection/Test (Battery Inspection/Test).
Reference Information
Schematic Reference
* Engine Controls Schematics (2.2L) (Electrical Diagrams)
* Power Distribution Schematics (Power Distribution Diagrams)
Connector End View Reference
Component Connector End Views (Connector Views)
Electrical Information Reference
* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions (Diagnostic Trouble Code Descriptions)
Scan Tool Reference
Control Module References (Programming and Relearning)for scan tool information
Circuit/System Verification
1. If DTCs P0685, P0689, P0690, or B1380 are set, diagnose those DTCs first.
2. Ignition ON, engine OFF, observe the Ignition 1 Voltage Signal, and the EC Ignition Relay Feedback Signal parameters, on the scan tool. Both parameter values should display no more than 3 volts difference, between the two parameters.
3. Ignition OFF, observe the Ignition 1 Voltage Signal parameter on the scan tool. The parameter value should be 0V, before the ECM powers down.
Circuit/System Testing
1. Ignition OFF, disconnect the Powertrain Relay.
2. Ignition ON, verify that a test lamp does not illuminate between the powertrain relay controlled output circuit terminal and ground.
• If the test lamp illuminates, test the powertrain relay controlled output circuit for a short to voltage.
3. Ignition OFF, verify that a test lamp illuminates between the powertrain relay coil voltage supply circuit terminal and ground.
• If the test lamp does not illuminate, test the powertrain relay coil voltage supply circuit for a short to ground or an open/high resistance.
4. Verify that a test lamp illuminates between the powertrain relay switch voltage supply circuit terminal and ground.
• If the test lamp does not illuminate, test the powertrain relay switch voltage supply circuit for an open/high resistance.
5. Disconnect the ECM.
6. Ignition ON, verify that a test lamp illuminates between ECM connector terminal 19 X1 and ground.
• If the test lamp does not illuminate, test the RUN/CRNK Relay controlled output circuit for a short to ground or open/high resistance. If the circuit tests normal and its fuse is open, replace the ECM.
7. Ignition OFF, connect the harness connector at the ECM.
8. Ignition ON, connect a 3A fused jumper wire between the powertrain relay voltage supply circuit terminal and the powertrain relay controlled output circuit terminal. Verify the EC Ignition Relay Feedback parameter indicates battery positive voltage.
• If not the specified value, test the powertrain relay controlled output circuit for a short to ground or an open/high resistance. If the circuit tests normal and its fuse is open, replace the ECM.
9. If all circuits test normal, replace the Powertrain Relay.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Relay Replacement (Attached to Wire Harness) (Relay Replacement (Attached to Wire Harness))Relay Replacement (Within an Electrical Center) (Relay Replacement (Within an Electrical Center))
* Control Module References (Programming and Relearning)for ECM replacement, setup, and programming