2010 Cadillac CTS Sedan AWD V6-3.6L Page 1225
Scan Tool Reference
Control Module References (See: Testing and Inspection/Programming and Relearning) for scan tool information
Circuit/System Verification
1. Verify that a vacuum leak is not present, refer to Brake System Vacuum Source Test (See: Brakes and Traction Control/Hydraulic
System/Testing and Inspection/Component Tests and General Diagnostics/Brake System Vacuum Source Test)
2. Ignition ON, command the relay ON and OFF with a scan tool. Observe to verify that the vacuum relay and motor turns ON and OFF with
each command.
Circuit/System Testing
1. Ignition OFF, disconnect the vacuum pump relay.
2. Ignition ON, verify that a test lamp does not illuminate between the control circuit terminal 87 and ground.
瀚慖f the test lamp illuminates, test the control circuit for a short to voltage.
3. Verify that a test lamp illuminates between the B+ circuit terminals listed below and ground.
* Terminal 30
* Terminal 86
瀚慖f the test lamp does not illuminate, test the B+ 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 relay.
4. Verify that a test lamp does not illuminate between the control circuit terminal 85 and ground.
瀚慖f the test lamp illuminates, test the control circuit for a short to voltage.
5. Disconnect the harness connector at the vacuum pump.
6. Test for less than 2 ohms between the vacuum pump ground circuit terminal 2 and ground.
瀚慖f greater than the specified range, test the ground circuit for an open/high resistance.
7. Connect the harness connector at the vacuum pump.
8. Connect a 20A fused jumper wire between the B+ circuit terminal 30 and the control circuit terminal 87. Verify the vacuum pump is
activated.
瀚慖f the vacuum pump does not activate, test the control circuit for a short ground or an open/high resistance. If the circuit tests normal, test
or replace the vacuum pump.
9. Ignition OFF, test for infinite resistance between the control circuit terminal 85 and ground.
瀚慖f less than the specified value, test the control circuit for a short to ground. If the circuit tests normal, replace the ECM.
10. Disconnect the X1 harness connector at the ECM.
11. Test for less than 2 ohms between the control circuit terminal 85 at the relay cavity and terminal 18 at the ECM harness connector.
瀚慖f greater than the specified range, test the control circuit for an open/high resistance.
12. If all circuits test normal, replace the brake booster pump relay. If the DTC resets, replace the power brake booster vacuum pump.
Component Testing
1. Ignition OFF, disconnect the vacuum pump relay.
2. Test for 60-180 ohms between terminals 85 and 86.
瀚慖f the resistance is not within the specified range, replace the relay.
3. Test for infinite resistance between the following terminals:
* 30 and 85
* 30 and 87
* 30 and 86
* 86 and 87
瀚慖f not the specified value, replace the relay.
4. Install a 30A fused jumper wire between relay terminal 86 and B+. Install a jumper wire between relay terminal 85 and ground.
