2010 Cadillac CTS Sedan AWD V6-3.6L Page 1581
* Connector Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/Connector Repairs/Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (See: Testing and Inspection/Component Tests and General Diagnostics/Circuit
Testing/Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/Wiring Repairs/Wiring Repairs)
Description and Operation
* Electronic Component Description (See: Transmission and Drivetrain/Automatic Transmission/Transaxle/Description and
Operation/Electronic Component Description)
* Transmission General Description (See: Transmission and Drivetrain/Automatic Transmission/Transaxle/Description and
Operation/Transmission General Description)
* Transmission Component and System Description (See: Transmission and Drivetrain/Automatic Transmission/Transaxle/Description and
Operation/Transmission Component and System Description)
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions (See: Diagnostic Trouble Code Descriptions/Powertrain Diagnostic Trouble Code
(DTC) Type Definitions)
Circuit/System Verification
1. Engine idling at normal operating temperature, verify the scan tool TCM Temperature parameter is between -247 and +247掳C (-412 and
+477掳F).
瀚慖f not within the specified range, replace the Q8 control solenoid valve assembly.
2. Operate the vehicle at 64 km/h (40 mph) for 10 minutes. Monitor the TCM Temperature parameter and the Transmission Fluid Temperature
parameter with a scan tool. The TCM Temperature parameter should increase by more than 2掳C (3.5掳F). Also, the TCM Temperature
parameter and the Transmission Fluid Temperature parameter should be within 10掳C (18掳F) of each other.
瀚慖f the TCM Temperature parameter does not increase by more than 2掳C (3.5掳F) or the TCM Temperature parameter value is not within 10
掳C (18掳F) of the Transmission Fluid Temperature parameter, then replace the Q8 control solenoid valve assembly.
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.
Repair Instructions
Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.
* Control solenoid valve assembly replacement. Refer to Control Module References (See: Testing and Inspection/Programming and
Relearning) for replacement, setup, and programming.
* Perform the Service Fast Learn Adapts (See: Transmission and Drivetrain/Automatic Transmission/Transaxle/Testing and
Inspection/Programming and Relearning/Service Fast Learn Adapts) following all transmission related repairs.
P0685
DTC P0685, P0686, P0687, P0689, or P0690
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
