P0690
DTC P0685, P0686, P0687, P0689, or P0690
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 Instructions) provides an overview of each diagnostic category.
DTC Descriptors
DTC P0685
- Engine Controls Ignition Relay Control Circuit
DTC P0686
- Engine Controls Ignition Relay Control Circuit Low Voltage
DTC P0687
- Engine Controls Ignition Relay Control Circuit High Voltage
DTC P0689
- Engine Controls Ignition Relay Feedback Circuit Low Voltage
DTC P0690
- Engine Controls Ignition Relay Feedback Circuit High Voltage
Diagnostic Fault Information
Typical Scan Tool Data
Circuit/System Description
The powertrain/engine controls ignition relay is a normally open relay. The relay switch is held in the open position by spring tension. Battery positive voltage is supplied directly to the relay coil and the relay switch contact at all times. The engine control module (ECM) supplies the ground path to the relay coil control circuit through an output driver module. The output driver module for the relay also incorporates a fault detection circuit, which is continuously monitored by the ECM. When the ECM commands the relay ON, ignition 1 voltage is supplied to fuses in the underhood fuse block.
The ignition 1 voltage that is supplied to the ECM, provides power to the internal ECM circuits associated with the throttle actuator control (TAC) operation. The ECM also monitors the voltage level on the ignition 1 voltage circuit to confirm that the powertrain relay contacts have closed.
Conditions for Running the DTC
P0685 and P0686
* The battery voltage is between 10.5-18 V.
* The ignition is ON.
* The relay has been commanded ON.
* These DTCs run continuously when the above conditions have been met.
P0687, P0689, and P0690
* The battery voltage is between 10.5-18 V.
* The ignition is OFF.
* The powertrain relay has been commanded OFF.
* These DTCs run continuously when the above conditions have been met.
Conditions for Setting the DTC
* The commanded state of the output driver module and the actual state of the control circuit do not match.
OR
* The ECM detects that the feedback voltage is not within a predicted range when the relay is commanded ON and OFF.
* Either condition is present for more than 2 seconds.
Action Taken When the DTC Sets
DTCs P0685, P0686, P0687, P0689, and P0690 are Type C DTCs.
Conditions for Clearing the DTC
DTCs P0685, P0686, P0687, P0689, and P0690 are Type C DTCs.
Diagnostic Aids
* This test procedure assumes that the vehicle battery has passed a load test and is completely charged. Refer to Battery Inspection/Test (Battery Inspection/Test).
* When disconnecting electrical connectors or removing fuses and relays from a fuse block, always inspect the component electrical terminals for corrosion and the mating electrical terminals for correct tension.
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 Views)
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)
* Probing Electrical Connectors (Probing Electrical Connectors)
* Electrical Center Identification Views (Application and ID)
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
Note: If you were sent here from Engine Cranks But Does Not Run, proceed to Circuit/System Testing.
1. Engine running, command the engine controls ignition relay ON and OFF with a scan tool while observing the following Engine Controls Ignition Relay Control Circuit Status parameters:
* Engine Controls Ignition Relay Control Circuit Low Voltage Test Status
* Engine Controls Ignition Relay Control Circuit Open Test Status
* Engine Controls Ignition Relay Control Circuit High Voltage Test Status
Each parameter should display OK or Not Run.
2. Ignition ON, you should be able to communicate with the ECM using a scan tool.
3. Ignition ON, view the DTC information with a scan tool. DTC P0685, P0686, P0687, P0689, or P0690 should not set.
4. 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
1. Ignition OFF, disconnect the KR75 powertrain relay.
2. Verify that a test lamp illuminates between the both of the following relay battery voltage circuit terminals and ground:
* Terminal 85
* Terminal 87
• If the test lamp does not illuminate, test the relay battery voltage circuit for an open/high resistance or a short to ground.
Note: The ignition voltage circuit is between the powertrain relay and the ECM. The ignition voltage circuit is a feedback circuit.
3. Ignition OFF, verify that a test lamp does not illuminate between the ignition voltage circuit terminal 30 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 87 and the relay switch ignition voltage circuit terminal 30.
5. Ignition ON, observe the scan tool Engine Control Ignition Relay Feedback Signal parameter. The ECM should communicate, and the parameter should display 9-14 V.
• If not the specified range, or the ECM does not communicate, test the ignition voltage circuit between the powertrain relay and the ECM for a short to ground or for 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 an open/high resistance. If the circuit tests normal, replace the K20 ECM.
9. If all circuits test normal, replace the KR75 powertrain relay.
Component Testing
1. Measure for 70-110 ohms between terminals 85 and 86 of the KR75 powertrain relay.
• If the resistance is not within the specified range, replace the KR75 powertrain relay.
2. Measure for infinite resistance between following terminals and the KR75 powertrain relay:
* Terminals 30 and 86
* Terminals 30 and 87
* Terminals 30 and 85
* Terminals 85 and 87
• If continuity is detected, replace the KR75 powertrain relay.
3. Connect a 20 A fused jumper wire from the positive terminal of the battery to relay terminal 85. Connect a jumper wire from the negative terminal of the battery to relay terminal 86. Measure for less than 2 ohms between terminals 30 and 87 of the relay.
• If the resistance measures more than 2 ohms, replace the KR75 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