2010 Cadillac Truck SRX FWD V6-3.0L Page 1138

2010 Cadillac Truck SRX FWD V6-3.0L Page 1138

Circuit/System Verification

1. Verify that DTC P0117, P0118, or P0119 is not set.

瀚慖f any of the DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle (See: Diagnostic Trouble Code

Descriptions/Diagnostic Trouble Code (DTC) List - Vehicle).

2. Inspect the engine coolant level. Verify that the cooling system is operating correctly.

瀚慖f you suspect a condition with engine cooling system, refer to Loss of Coolant (See: Engine, Cooling and Exhaust/Cooling

System/Testing and Inspection/Symptom Related Diagnostic Procedures/Loss of Coolant).

3. Ignition ON, verify the P0116 Freeze Frame Start Up ECT and the Start Up IAT parameters are within 14掳C (25掳F).

4. 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 B34 ECT sensor.

Caution: Do NOT use a test lamp to test the continuity of the circuit. Damage to the control module may occur due to excessive current

draw.

Note: The control module or the sensor may be damaged if the circuit is shorted to battery positive voltage.

2. Test for less than 5 ohm between the low reference circuit terminal A and ground.

瀚慖f greater than the specified range, test the low reference circuit for an open/high resistance, or for a short to voltage. If the circuit tests

normal, replace the K20 ECM.

3. Ignition ON, verify that the scan tool ECT sensor parameter is at -40掳C (-40掳F).

瀚慖f warmer than the specified value, test the signal circuit for a short to ground. If the circuit tests normal, replace the K20 ECM.

Note: If the fuse in the jumper wire opens, the signal circuit is shorted to a voltage and the sensor may be damaged.

4. Ignition ON, install a 3 A fused jumper wire between the signal circuit terminal A and the low reference circuit terminal B. Verify the ECT

sensor parameter is warmer than 142掳C (288掳F).

瀚慖f colder than the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace

the K20 ECM.

5. If all circuits test normal, test or replace the B34 ECT sensor.

Component Testing

1. Ignition OFF, disconnect the harness connector at the B34 engine coolant temperature (ECT) sensor.

Note: A thermometer can be used to test the sensor off the vehicle.

2. Test the ECT sensor by varying the sensor temperature while monitoring the sensor resistance. Compare the readings with the Temperature

Versus Resistance - Engine Coolant Temperature Sensor (See: Powertrain Management/Computers and Control

Systems/Specifications/Temperature Versus Resistance - Engine Coolant Temperature Sensor) table and verify that the resistance is within 5

% of the specification.

瀚慖f not within the specified range, replace the B34 ECT sensor.

Repair Instructions

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

* Engine Coolant Temperature Sensor Replacement (LF1) (See: Engine, Cooling and Exhaust/Cooling System/Engine - Coolant Temperature

Sensor/Switch/Coolant Temperature Sensor/Switch (For Computer)/Service and Repair)Engine Coolant Temperature Sensor Replacement

(LAU) (See: Engine, Cooling and Exhaust/Cooling System/Engine - Coolant Temperature Sensor/Switch/Coolant Temperature

Sensor/Switch (For Computer)/Service and Repair)

* Control Module References (See: Testing and Inspection/Programming and Relearning) for ECM replacement, setup, and programming