P0689
DTC P0685, P0686, P0687, P0689, or P0690 (LE0/LLT/LY7)
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
Circuit/System Description
The engine controls (EC) ignition relay, or powertrain 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 switch contact at all times. The engine control module (ECM) supplies the ground path to the relay coil control circuit via an internal integrated circuit called an output driver. When the ECM commands the powertrain relay ON, ignition voltage is supplied to several fuses in the underhood fuse block.
The ignition voltage that is supplied to the ECM, by the powertrain relay, 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 voltage circuit to confirm that the powertrain relay contacts have closed.
Conditions for Running the DTC
P0685, P0686, and P0687
* The ignition voltage is between 10-18 V.
* The engine speed is greater than 80 RPM.
* The powertrain relay has been commanded ON and OFF.
* The DTCs run continuously when the above conditions are met.
P0689 and P0690
* The ignition voltage is between 10-18 V.
* The ignition is ON.
* The DTCs runs continuously when the above conditions are met.
Conditions for Setting the DTC
P0685, P0686, and P0687
The commanded state of the driver and the actual state of the control circuit do not match for greater than 4 s or for a cumulative of 30 s.
P0689 and P0690
The ECM detects that powertrain relay feedback voltage is less than 6 V for greater than 1 s, when the powertrain relay is commanded ON or OFF. The condition exists for 4 s, or for a cumulative of 30 s.
Action Taken When the DTC Sets
DTCs P0685, P0686, P0687, P0689, and P0690 are Type C DTCs.
Conditions for Clearing the MIL/DTC
DTCs P0685, P0686, P0687, P0689, and P0690 are Type C DTCs.
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).
* An open in the relay control circuit will cause no communication with the ECM when the ignition switch is cycled OFF and then ON after the initial failure. The malfunction indicator lamp (MIL) will flash rapidly and other relays can be heard turning on and off with the ignition ON.
* 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 tightness.
* Use the J 35616 Connector Test Adapter Kit for any test that requires probing the underhood fuse block terminals, component wire harness terminals, or the ECM wire harness connector terminals.
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)
* Electrical Center Identification Views (Application and ID)
* Testing for Intermittent Conditions and Poor Connections (Testing For Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)
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
Special Tools
J 35616 Connector Test Adapter Kit
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 (EC) Ignition Relay ON and OFF with a scan tool while observing the following EC 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 in each commanded state.
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
Note: You must perform the Circuit/System Verification first.
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 a short to ground or an open/high resistance.
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 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 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
Note: Depending on the application, the relay coil resistance will be within one of the following ranges.
1. Test for one of the following resistance specifications between terminals 85 and 86 of the KR75 powertrain relay:
* 70-110 ohm
* 200-250 ohm
• If not within the specified range, replace the KR75 powertrain relay.
2. Measure for infinite resistance between the following terminals of the KR75 powertrain relay:
* 30 and 86
* 30 and 87
* 30 and 85
* 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 greater than the specified value, 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 engine control module replacement, setup, and programming