2010 Cadillac Truck SRX AWD V6-2.8L Turbo Page 219
Circuit/System Testing
1. Ignition OFF, disconnect the KR73 ignition main relay.
2. Ignition OFF and all vehicle systems OFF. It may take up to 2 minutes for all vehicle systems to power down. Test for less than 10 ohm
between the relay ground circuit and ground.
瀚慖f greater than the specified range, test the ground circuit for an open/high resistance.
3. Ignition ON, verify that a test lamp illuminates between the relay B+ circuit and ground.
瀚慖f the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.
4. Connect a test lamp between the relay control circuit and ground.
5. Cycle the ignition ON and OFF. The test lamp should turn ON and OFF when changing S39 ignition switch positions.
瀚慖f the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the K9 BCM.
瀚慖f the test lamp is always OFF, test the control circuit for a short to ground or open/high resistance. If the circuit tests normal, replace the
K9 BCM.
6. If all circuits test normal, test or replace the KR73 ignition main relay.
Component Testing
1. Ignition OFF, disconnect the KR73 ignition main relay.
2. Test for 70-150 Ohms between terminals 85 and 86.
瀚慖f the resistance is not within the specified range, replace the KR73 ignition main relay.
3. Test for infinite resistance between the following terminals:
* 30 and 86
* 30 and 87
* 30 and 85
* 85 and 87
瀚慖f less than specified, replace the KR73 ignition main relay.
4. Install a 3 A fused jumper wire between relay terminal 86 and 12 V. Install a jumper wire between relay terminal 85and ground. Measure for
less than 5 Ohms between terminals 87 and 30.
瀚慖f greater than specified, replace the KR73 ignition main relay.
Repair Instructions
Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the repair.
* Relay Replacement (Attached to Wire Harness) (See: Power and Ground Distribution/Power Distribution Relay/Service and Repair/Relay
Replacement (Attached to Wire Harness))Relay Replacement (Within an Electrical Center) (See: Power and Ground Distribution/Power
Distribution Relay/Service and Repair/Relay Replacement (Within an Electrical Center))
* Control Module References (See: Testing and Inspection/Programming and Relearning) for BCM replacement, setup, and programming
B144B
DTC B144B
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic System
Check - Vehicle) 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)
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)Diagnostic Procedure Instructions provides an overview of each diagnostic category.
DTC Descriptor
DTC B144B 01
- Run/Start Power Relay Circuit Short to Battery
