P0689
DTC P0685, P0689, or P0690 (LUW)
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 Descriptor
DTC P0685
- Engine Controls Ignition Relay Control Circuit
DTC P0689
- Engine Controls Ignition Relay Feedback Circuit Low Voltage
DTC P0690
- Engine Controls Ignition Relay Feedback Circuit High Voltage
Circuit/System Description
The powertrain relay is an electrical switch that opens and closes under the control of the engine control module. The powertrain 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 ignition main relay also incorporates a fault detection circuit, which is continuously monitored by the ECM. When the ECM commands the powertrain relay ON, switched battery voltage is supplied to fuses in the underhood fuse block. The switched battery 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 switched battery circuit to confirm that the powertrain relay contacts have closed.
Conditions for Running the DTC
* The ignition is ON, or the engine is running.
* The ignition voltage is between 11-32 V.
* These DTCs run continuously once the above conditions are met.
Conditions for Setting the DTC
P0685
The ECM detects that the commanded state of the driver and the actual state of the control circuit do not match for greater than 2 s.
P0689
The ECM detects the engine controls powertrain relay feedback circuit is less than 5 V when the relay is commanded ON for 5 s.
P0690
* The ECM detects the engine controls powertrain relay feedback circuit is greater than 2 V when the relay is commanded OFF.
* The ECM detects the engine controls powertrain relay feedback circuit is greater than 18 V when the relay is commanded ON.
Action Taken When the DTC Sets
DTCs P0685, P0689, and P0690 are Type B DTCs.
Conditions for Clearing the DTC
DTCs P0685, P0689, and P0690 are Type B DTCs.
Reference Information
Schematic Reference
Engine Controls Schematics (LUW) [1][2]Electrical Diagrams
Connector End View Reference
Component Connector End Views Sunshade - Left (D6I)
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
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References Control Module References 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. Ignition OFF, allow the ECM to completely power down. Probe both test points of F9, F10, and F11 fuses supplied with voltage by the KR75 Engine Controls Ignition Relay. The test lamp should not illuminate on any test point of any fuse.
2. Ignition ON, probe both test points of F8, F9, F10, F11, F46, and F47 fuses supplied with voltage by the KR75 Engine Controls Ignition Relay. The test lamp should illuminate on at lease one test point of each fuse.
3. 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 Engine Controls Ignition Relay.
2. Verify that a test lamp illuminates between the KR75 Engine Controls Ignition Relay coil B+ socket circuit terminal 2 and ground.
• If the test lamp does not illuminate, repair the KR75 Engine Controls Ignition Relay coil B+ circuit for a short to ground or an open/high resistance.
3. Wait for 120 s to allow the ECM to completely power down, connect a test lamp between the KR75 Engine Controls Ignition Relay coil control socket circuit terminal 1 and the relay coil B+ socket circuit terminal 2.
• If the test lamp is always ON, test the KR75 Engine Controls Ignition Relay coil control circuit for a short to ground. If the circuit tests normal, replace the K20 Engine Control Module.
4. Ignition ON. The test lamp should turn ON.
• If the test lamp is always OFF, test the KR75 Engine Controls Ignition Relay coil control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the K20 Engine Control Module.
Note: The ignition voltage circuit is between the KR75 Engine Controls Ignition Relay circuit 5 and the ECM through fuse F10. The ignition voltage is a feedback circuit.
5. Install a 15 A fused jumper wire between the KR75 Engine Controls Ignition Relay switch B+ socket circuit terminal 3 and the KR75 Engine Controls Ignition Relay switch ignition voltage socket circuit terminal 5.
6. Attempt to start the engine. The engine should start.
7. If the engine does not start, test the KR75 Engine Controls Ignition Relay switch ignition voltage circuit between the KR75 Engine Controls Ignition Relay circuit terminal 5 and the ECM connector X1 terminals 3 for a short to ground or for an open/high resistance. If the circuit tests normal, replace the K20 Engine Control Module.
8. If all circuits test normal, test or replace the KR75 Engine Controls Ignition Relay.
Component Testing
Relay Test
1. Ignition OFF, disconnect the KR75 Engine Controls Ignition Relay.
2. Measure for 70-110 ohm between terminals 1 and 2 of the KR75 Engine Controls Ignition Relay.
• If the resistance is not within the specified range, replace the KR75 Engine Controls Ignition Relay.
3. Measure for infinite resistance between following terminals of the KR75 Engine Controls Ignition Relay:
* Terminals 3 and 1
* Terminals 3 and 5
* Terminals 3 and 2
* Terminals 2 and 5
• If continuity is detected, replace the KR75 Engine Controls Ignition Relay.
4. Connect a 20 A fused jumper wire from the positive terminal of the battery to KR75 Engine Controls Ignition Relay terminal 2. Connect a jumper wire from the negative terminal of the battery to KR75 Engine Controls Ignition Relay 1. Measure for less than 5 ohm between KR75 Engine Controls Ignition Relay 3 and KR75 Engine Controls Ignition Relay socket terminal 5.
• If the resistance measures more than 5 ohm, replace the KR75 Engine Controls Ignition 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 Control Module References for Engine Control Module replacement, programming and setup.