2010 Cadillac Truck SRX AWD V6-2.8L Turbo Page 1387

2010 Cadillac Truck SRX AWD V6-2.8L Turbo Page 1387

DTCs P0480, P0691, and P0692 are Type B DTCs.

Diagnostic Aids

The ECM has the capability of providing command to the fan module even when a scan tool output control is being used. Always refer to the fan

control command parameters on the scan tool to know when the fan is being commanded ON by the ECM.

Reference Information

Schematic Reference

Engine Cooling Schematics (See: Engine, Cooling and Exhaust/Cooling System/Diagrams)

Connector End View Reference

Component Connector End Views (See: Diagrams/Connector Views/Connector End Views By Name)

Description and Operation

Cooling Fan Description and Operation (LAU) (See: Engine, Cooling and Exhaust/Cooling System/Description and Operation/Cooling Fan

Description and Operation)Cooling Fan Description and Operation (LF1) (See: Engine, Cooling and Exhaust/Cooling System/Description and

Operation/Cooling Fan Description and Operation)

Electrical Information Reference

* Circuit Testing (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/Circuit

Testing/Circuit Testing)

* Connector Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic

Procedures/Connector Repairs/Connector Repairs)

* Testing for Intermittent Conditions and Poor Connections (See: Testing and Inspection/Component Tests and General Diagnostics/General

Electrical Diagnostic Procedures/Circuit Testing/Testing for Intermittent Conditions and Poor Connections)

* Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/Wiring

Repairs/Wiring Repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions (See: Diagnostic Trouble Code Descriptions/Powertrain Diagnostic Trouble Code

(DTC) Type Definitions)

Scan Tool Reference

Control Module References (See: Testing and Inspection/Programming and Relearning) for scan tool information

Circuit/System Verification

Note: There is a slight delay before the cooling fans activate.

1. Ignition ON, command the cooling fan ON and OFF with a scan tool. The cooling fan should respond to the commanded states.

2. Observe the DTC information with a scan tool. DTC P0480, P0691, or P0692 should not set.

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 harness connector at the K22 cooling fan control module.

2. Verify that a test lamp illuminates between the ground circuit terminal 2 and B+.

瀚慖f the test lamp does not illuminate, test the ground circuit for an open/high resistance.

3. Ignition ON, verify that a test lamp illuminates between the B+ supply circuit terminal 1 and ground.

瀚慖f the test lamp does not illuminate, test the circuit for a short to ground or an open/high resistance. If the circuit tests normal and the B+

circuit fuse is open, test or replace the K22 cooling fan control module.

Note: The cooling fan speed control circuit is pulled-up to a voltage within the ECM, 3-4 volts on the control circuit is normal.

4. Test for 3-4 V between the control circuit terminal 4 and ground.

瀚慖f less than the specified range, test the control circuit for an open or a short to ground. If the circuit tests normal, replace the K20 ECM.

瀚慖f greater than the specified range, test the control circuit for a short to voltage. If the circuit tests normal, replace the K20 ECM.

5. Command the cooling fan ON and OFF with a scan tool. The DMM should transition from 3-4 V when commanded OFF to less than 1 V,

when commanded ON to greater than 70 %.

2010 Cadillac Truck SRX AWD V6-2.8L Turbo Page 1765

2010 Cadillac Truck SRX AWD V6-2.8L Turbo Page 1765

1. If DTC P0480, P0481, P0691, P0692, P0693, or P0694 is set, diagnose that DTC first.

2. Observe the engine coolant level. The engine coolant level should be within the operating range. Refer to Capacities - Approximate Fluid,

and Engine Coolant in the Owner's Manual.

3. Ensure that the vehicle has the correct engine coolant with correct concentration and is not old, contaminated, or contains additives. Refer to

Recommended Fluids and Lubricants in the Owner's Manual.

4. Inspect the cooling system for the following:

* Leaks

* Kinked or pinched hoses, especially at the radiator

* Loose, missing, or damaged radiator air seals or deflectors

* Air flow obstructions or bent fins at the radiator or the A/C condenser-Refer to Symptoms - Engine Cooling (See: Engine, Cooling and

Exhaust/Cooling System/Testing and Inspection/Symptom Related Diagnostic Procedures/Symptoms - Engine Cooling).

Note: A small delay occurs before the ECM changes the cooling fan speed.

5. Command the cooling fans ON and OFF, low and high speed. The engine cooling fans should turn ON and OFF with each command.

瀚慖f the cooling fans do not function as indicated, refer to Cooling Fan Inoperative (LAU) (See: Engine, Cooling and Exhaust/Cooling

System/Testing and Inspection/Symptom Related Diagnostic Procedures/Cooling Fan Inoperative)Cooling Fan Inoperative (LF1) (See:

Engine, Cooling and Exhaust/Cooling System/Testing and Inspection/Symptom Related Diagnostic Procedures/Cooling Fan Inoperative).

Circuit/System Testing

1. Test the thermostat for correct operation. Refer to Thermostat Diagnosis (See: Engine, Cooling and Exhaust/Cooling System/Testing and

Inspection/Symptom Related Diagnostic Procedures/Thermostat Diagnosis).

2. Test the engine cooling system for overheating. Refer to Engine Overheating (See: Engine, Cooling and Exhaust/Cooling System/Testing

and Inspection/Symptom Related Diagnostic Procedures/Engine Overheating).

3. Inspect the water pump and coolant flow for correct operation. Refer to Water Pump Cleaning and Inspection (See: Engine, Cooling and

Exhaust/Engine/Service and Repair/Overhaul/100. Water Pump Cleaning and Inspection).

4. Inspect the engine mechanical for worn, leaking, cracked cylinder heads or engine block. Refer to Coolant in Engine Oil (See: Engine,

Cooling and Exhaust/Engine/Testing and Inspection/Symptom Related Diagnostic Procedures/Coolant in Engine Oil).

Repair Instructions

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

P1551

DTC P1551

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 Descriptor

DTC P1551

- Throttle Valve Rest Position Not Reached During Learn

Circuit/System Description

The engine control module (ECM) controls the throttle valve by applying a varying voltage to the control circuits of the throttle actuator control

(TAC) motor. The ECM monitors the duty cycle that is required to actuate the throttle valve. The ECM monitors the throttle position sensors 1 and

2 to determine the actual throttle valve position.

Conditions for Running the DTC

* The vehicle speed is 0 km/h (0 mph).

* The engine speed is less than 40 RPM.

* The engine coolant temperature (ECT) is between 5-100掳C (41-212掳F).

* The intake air temperature (IAT) is between 5-143掳C (41-290掳F).

* The ignition voltage is greater than 10 volts.

* The accelerator pedal position (APP) is less than 15 percent.