P0689
DTC P0689
CIRCUIT DESCRIPTION
The powertrain relay is a normally open relay. The relay armature is held in the open position by spring tension. Battery positive voltage is supplied directly to the relay coil and the armature 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 module (ODM). When the ECM commands the powertrain relay ON, ignition 1 voltage is supplied to the ECM through the ECM 2 fuse in the underhood fuse block. This ignition 1 voltage input to the ECM provides the ignition power for the throttle actuator control (TAC) circuitry, and is also used to confirm the powertrain relay contacts have closed. This DTC will set when the ECM detects less than 10 volts on the ignition 1 voltage circuit to the ECM, after the ignition switch is turned ON. DTC P0689 indicates an open, high resistance, or short to ground in the ignition 1 voltage circuit to the ECM.
DTC DESCRIPTOR
This diagnostic procedure supports the following DTC:
DTC P0689 Computers and Control Systems Ignition Relay Feedback Circuit Low Voltage
CONDITIONS FOR RUNNING THE DTC
- The battery voltage is between 9-16 volts.
- The ignition switch is turned ON.
- The powertrain relay has been commanded ON.
CONDITIONS FOR SETTING THE DTC
The ECM detects less than 10 volts on the ECM 2 ignition 1 voltage circuit for 5 seconds.
ACTION TAKEN WHEN THE DTC SETS
- The control module stores the DTC information into memory when the diagnostic runs and fails.
- The malfunction indicator lamp (MIL) will illuminate.
- The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in Failure Records.
- The driver information center, if equipped, may display a message.
CONDITIONS FOR CLEARING THE MIL/DTC
- A current DTC, last test failed clears when the diagnostic runs and passes.
- A history DTC clears 40 consecutive warm-up cycles, if no other failures are reported or any other emission related diagnostic.
- Clear the DTC with a scan tool.
TEST
