2010 Cadillac Truck SRX AWD V6-2.8L Turbo Page 1528

2010 Cadillac Truck SRX AWD V6-2.8L Turbo Page 1528

Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.

Control Module References (See: Testing and Inspection/Programming and Relearning) for control solenoid valve assembly replacement, setup,

and programming

P0685

DTC P0685, P0686, P0687, P0689, or P0690 (LAU)

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic System

Check - Vehicle) prior to using this diagnostic procedure.

* Review Strategy Based Diagnosis (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Strategy Based Diagnosis) for an

overview of the diagnostic approach.

* Diagnostic Procedure Instructions (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/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 1 voltage that is supplied to the ECM through the ETC fuse 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, 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 once the above condition is met.

P0689 and P0690

* The ignition voltage is between 10-18 V.

* The ignition is ON.

* The DTCs runs continuously once the above condition is met.