Cruze |
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• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
• | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
• | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
Circuit | Short to Ground | High Resistance | Open | Short to Voltage | Signal Performance |
---|---|---|---|---|---|
Battery Supply Voltage - Coil | P0686 00 | P0686 00 | P0686 00 | - | - |
Battery Supply Voltage - Armature | P0689 00 | P0689 00 | P0689 00 | - | - |
Relay Control Circuit | - | P0686 00 | P0686 00 | P0687 00 | - |
Relay Feedback Control Circuit | P0689 00, P0688 00 | P0689 00, P0688 00 | P0689 00, P0688 00 | - | - |
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 under bonnet 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.
• | The ignition is ON or the engine is running. |
• | DTC P0606 00 is not set. |
• | The ignition is ON. |
• | DTC P0686 00 or P0687 00 is not set. |
Shortcut to ground or voltage in the control circuit.
DTCs P0686 00, P0687 00, P0688 00 are Type C DTCs.
• | DTCs P0686 00, P0687 00, P0688 00 are Type C DTCs. |
• | With a DTC set, the engine may crank for an extended period of time during start-up. |
• | This test procedure requires that the vehicle battery has passed a load test and is completely charged. Refer to 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 EL-35616-E GM-Approved Terminal Test Kit for any test that requires probing the under bonnet fuse block terminals, component wire harness terminals, or the ECM wire harness connector terminals. |
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
EL-35616-E GM-Approved Terminal Test Kit
For equivalent regional tools, refer to Special Tools .
⇒ | If the voltage measures less than 11 V, repair the open or high resistance between B+ and KR75 Powertrain Relay socket terminal 2, 3. |
⇒ | If the voltage measures greater than 0.3 V, test the control circuit for a short to voltage between KR75 Powertrain Relay socket terminal 1 and K20 Engine Control Module terminal 21 (X1). If the circuit tests normal, replace the K20 Engine Control Module. |
⇒ | If the test lamp illuminates, test the control circuit for a short to ground between KR75 Powertrain Relay socket terminal 1 and K20 Engine Control Module terminal 21 (X1). If the circuit tests normal, replace the K20 Engine Control Module. |
⇒ | If the test lamp is OFF, test the control circuit for an open/high resistance between KR75 Powertrain Relay socket terminal 1 and K20 Engine Control Module terminal 21 (X1). If the circuit tests normal, replace the K20 Engine Control Module. |
⇒ | If the voltage measures greater than 0.3 V, test the ignition voltage circuit for a short to voltage between KR75 Powertrain Relay socket terminal 5 and K20 Engine Control Module terminal 50 (X1), 6 (X2). If the circuit tests normal, replace the K20 Engine Control Module. |
⇒ | If the resistance measures greater than 5 Ω, repair the open or high resistance between K20 Engine Control Module terminal 50 (X1), 6 (X2) and KR75 Powertrain Relay socket terminal 5. |
⇒ | If the voltage measures less than 11 V, replace the KR75 Powertrain Relay. |
⇒ | If the resistance is not within the specified range, replace 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. |
⇒ | If the resistance measures more than 5 Ω, replace the KR75 Powertrain Relay. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Relay Replacement : Attached to Wire Harness |
• | Control Module References for Engine Control Module replacement, setup, and programming |
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