P1682
DTC P1682
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions Diagnostic Procedure Instructionsprovides an overview of each 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 voltage circuits supplied to the engine control module (ECM). The first ignition circuit is provided by the powertrain relay, through a fuse. This ignition voltage circuit supplies power to all the internal ECM circuits associated with the throttle actuator control (TAC) operation. The second ignition voltage circuit is supplied by the run/crank relay through a fuse, and is used to power the remaining internal ECM circuits.
Conditions for Running the DTC
* The ignition is ON.
* System voltage is greater than 5.5 V.
* The powertrain relay is commanded ON.
* DTC P1682 runs continuously when the above conditions are met.
Conditions for Setting the DTC
The ECM detects that the voltage level difference is greater than 3 V between the two ignition voltage circuits for less than 1 s.
Action Taken When the DTC Sets
DTC P1682 is a Type A DTC.
Conditions for Clearing the DTC
DTC P1682 is a Type A 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 [1][2]Electrical Diagrams
* Power Distribution Schematics Power Distribution Schematics
Connector End View Reference
Component Connector End Views Connector End Views By Name
Electrical Information Reference
* Circuit Testing Circuit Testing
* Connector Repairs Connector Repairs
* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs Wiring Repairs
* Electrical Center Identification Views Fuse Block - Auxiliary Label
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References Programming and Relearning for scan tool information
Circuit/System Verification
1. Ignition OFF, open the hood to disable the Auto-Stop function. Refer to Hybrid Modes of Operation Description Hybrid Modes of Operation.
2. Ignition ON, verify the scan tool hood position parameter displays Open.
• If the hood position does not display Open, refer to Diagnostic Trouble Code (DTC) List - Vehicle Diagnostic Trouble Code (DTC) List - Vehicle for DTC P254F.
Note: On the scan tool, the powertrain relay is referred to as the EC ignition relay.
3. Ignition ON, observe the scan tool DTC information. Verify DTC P0685 or P0690 is not set.
• If a DTC is set, refer to Diagnostic Trouble Code (DTC) List - Vehicle Diagnostic Trouble Code (DTC) List - Vehicle for further diagnosis.
4. Ignition ON, engine OFF, observe the scan tool Ignition 1 Voltage signal and the EC Ignition Relay Feedback signal parameters. There should be no greater than 3 V difference between the 2 parameters.
5. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
Circuit/System Testing
Note: You must perform the Circuit/System Verification before proceeding with Circuit/System Testing.
Note:
* The ignition 1 signal is supplied by the Run/Crank relay. The EC ignition relay feedback signal is supplied by the powertrain relay.
* High resistance in the ignition 1 signal or EC ignition relay feedback circuit/underhood fuse block will cause the DTC to set.
1. Ignition OFF, disconnect the KR75 powertrain relay.
2. Verify a test lamp illuminates between both of the following relay battery voltage circuit terminals and ground:
* Terminal 85
* Terminal 30
• If the test lamp does not illuminate, test the relay battery voltage circuit for an open/high resistance or a short to ground.
3. Ignition OFF, verify that a test lamp does not illuminate between the ignition voltage circuit terminal 87 and ground.
• If the test lamp illuminates, test the ignition voltage circuit for a short to voltage.
4. Connect a 20 A fused jumper wire between the relay switch B+ circuit terminal 30 and the relay switch ignition voltage circuit terminal 87.
5. Ignition ON, observe the scan tool EC Ignition Relay Feedback Signal parameter. The ECM should communicate, and the parameter should display B+.
• If not the specified value, or the ECM does not communicate, test the ignition voltage circuit between the powertrain relay and the ECM for a short to ground or an open/high resistance. If the circuit/connections test normal, replace the K20 ECM.
6. Ignition OFF, verify that a test lamp does not illuminate between the control circuit terminal 86 and B+.
• If the test lamp illuminates, test the control circuit for a short to ground. If the circuit tests normal, replace the K20 ECM.
7. Connect a DMM set to the diode setting between the control circuit terminal 86 and ground.
8. Ignition ON, verify the DMM does not display OL.
• If the DMM displays OL, test the control circuit for a short to voltage or open/high resistance. If the circuit tests normal, replace the K20 ECM.
9. If all circuits test normal, replace the KR75 powertrain relay.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.
* Relay Replacement
* Control Module References Programming and Relearningfor ECM replacement, setup, and programming