2010 Cadillac Truck SRX AWD V6-2.8L Turbo Page 1933

2010 Cadillac Truck SRX AWD V6-2.8L Turbo Page 1933

4. Test for greater than 2 ohm between UBEC B+ supply cable and the Afterboil PUMP Fuse 4.

瀚慖f less than the specified range, replace the X50A UBEC.

5. Connect a 10 A fused jumper wire from the positive terminal of the battery to the powertrain relay switched output circuit terminal 87.

Connect a jumper wire from the negative terminal of the battery to the auxiliary coolant pump relay control circuit at UBEC terminal X2-21.

Test for less than 2 ohm between UBEC B+ supply cable and the Afterboil PUMP Fuse 4.

瀚慖f greater than the specified range, replace the X50A UBEC.

Repair Instructions

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

* Fuse Block Replacement (See: Maintenance/Fuses and Circuit Breakers/Fuse Block/Service and Repair/Removal and Replacement/Fuse

Block Replacement)

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

P2602

DTC P2600-P2603

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 P2600

- Auxiliary Coolant Pump Relay Control Circuit

DTC P2601

- Auxiliary Coolant Pump Performance

DTC P2602

- Auxiliary Coolant Pump Relay Control Circuit Low Voltage

DTC P2603

- Auxiliary Coolant Pump Relay Control Circuit High Voltage

Diagnostic Fault Information

Circuit/System Description

The auxiliary coolant pump and cooling fan system provides a measure of prevention against fuel vaporization due to excessive engine

temperatures. The engine control module (ECM) commands the auxiliary or after boil coolant pump ON when the engine coolant temperature

exceeds a calibrated value after engine shut down. The ECM applies ground to the coil side of the auxiliary pump printed circuit board (PCB) relay.

This energizes the coil and applies voltage directly to the pump motor through the switch side of the relay.

Conditions for Running the DTC

P2600, P2602, or P2603

* The engine speed is greater than 80 RPM.

* The ignition voltage is between 10-18 V.

* The ECM has commanded the pump ON and OFF at least once during the ignition cycle.

* The DTCs run continuously once the above conditions are met.