2010 Cadillac Truck SRX FWD V6-3.0L Page 2066

2010 Cadillac Truck SRX FWD V6-3.0L Page 2066

conditions that you observed from the Freeze Frame/Failure Records data.

Circuit/System Testing

Caution: Use the connector test adapter kit J 35616-A for any test that requires probing the following items:

* The control module harness connectors

* The electrical center fuse/relay cavities

* The component terminals

* The component harness connector

Using this kit will prevent damage caused by the improper probing of connector terminals.

Note: Refer to Diagnostic Aids before performing the Circuit/System Testing.

1. Ignition OFF, disconnect harness connector X2 at the K20 ECM.

2. Connect a test lamp between terminal X2-45 and ground.

Note:

* A DMM connected between the test lamp probe and ground will measure 5-6 V if the test lamp illuminates with low intensity. The

voltage will measure near B+ if the test lamp illuminates with bright intensity.

* The values listed above are based on the use of the J-35616-210 test lamp, or a comparable test lamp that has approximately 30 ohm of

internal resistance.

3. Ignition ON, connect a fused jumper wire between the powertrain relay control circuit terminal X2-58 and ground. The test lamp should

illuminate with low intensity.

瀚慖f the test lamp does not illuminate, test the auxiliary coolant pump relay control circuit for a short to ground or an open/high resistance.

If the circuit tests normal, test or replace the X50A underhood fuse block (UBEC).

瀚慖f the test lamp illuminates with bright intensity, test the auxiliary coolant pump relay control circuit for a short to voltage. If the circuit

tests normal, test or replace the X50A UBEC.

4. If all circuits/connections test normal, replace the K20 ECM.

Component Testing

1. Ignition OFF, disconnect and remove the X50A UBEC.

2. Remove the KR75 powertrain relay.

3. Test for 170-210 ohm between the powertrain relay switched output circuit terminal 87 and the auxiliary coolant pump relay control circuit at

UBEC terminal X2-21.

瀚慖f not within the specified range, replace the X50A UBEC.

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.