Pinpoint Test A: No Power in All Ignition Switch Positions

Steering Column Switches

Pinpoint Test A: No Power in All Ignition Switch Positions



Normal Operation - Vehicles not equipped with a Circuit Deactivation Ignition Module (CDIM)

The ignition switch receives fused battery voltage from Body Control Module (BCM) permanent voltage bus through fuse 28 (15A). The ignition switch distributes the voltage to the BCM (Body Control Module) internal logic, PCM and Brake Shift Interlock Actuator (BSIA).

Normal Operation - Vehicles equipped with a CDIM (Circuit Deactivation Ignition Module)

The ignition switch and the CDIM (Circuit Deactivation Ignition Module) work together to distribute fused battery voltage to the BCM (Body Control Module) internal logic, PCM and BSIA (Brake Shift Interlock Actuator). When the ignition switch is placed in the ACC position, the CDIM (Circuit Deactivation Ignition Module) is in a passive state allowing the voltage to pass through the module using normally closed relays. When the ignition switch is placed in the RUN position the CDIM (Circuit Deactivation Ignition Module) becomes active. While active, the CDIM (Circuit Deactivation Ignition Module) allows ignition voltage to pass through the internal relays, but it also monitors the Medium Speed Controller Area Network (MS-CAN) for messages. Voltage is supplied to the BCM (Body Control Module) through the CDIM (Circuit Deactivation Ignition Module), when the ignition switch is placed in the ACC, RUN and START positions.

This pinpoint test is intended to diagnose the following:

- Fuse(s)

- Wiring, terminals or connectors

- Ignition switch

- BCM (Body Control Module)

PINPOINT TEST A : NO POWER IN ALL IGNITION SWITCH POSITIONS

NOTICE: Use the Flex Probe Kit for all test connections to prevent damage to the wiring terminals. Do not use standard multi-meter probes.

A1 CHECK THE VOLTAGE TO THE IGNITION SWITCH

- Disconnect: Ignition Switch C250.

- Measure the voltage between ignition switch C250-4, circuit SBP28 (GN/RD or BU/RD), harness side and ground.





Is the voltage greater than 10 volts?

Yes
GO to A2.

No
VERIFY BCM (Body Control Module) fuse 28 (15A) is OK. If OK, GO to A3.

If not OK, REFER to the Wiring Diagrams to identify the possible causes of the short circuit. REPAIR as necessary. TEST the system for normal operation. [1][2]Diagrams By Number

A2 CHECK THE ELECTRICAL IGNITION SWITCH CONNECTOR

- Check the electrical connector for:
- corrosion

- damaged pins

- pushed-out pins


- Repair any identified concerns.

- Connect the ignition switch connector and make sure it seats correctly.

- Operate the system and verify the concern is still present.

Is the concern still present?

Yes
INSTALL a new ignition switch. REFER to Ignition Switch . TEST the system for normal operation.

No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.

A3 CHECK THE IGNITION SWITCH SUPPLY CIRCUIT FOR AN OPEN

- Disconnect: BCM (Body Control Module) C2280A.

- Measure the resistance between BCM (Body Control Module) C2280A-6, circuit SBP28 (GN/RD or BU/RD), harness side and ignition switch C250-4, circuit SBP28 (GN/RD or BU/RD, harness side.





Is the resistance less than 5 ohms?

Yes
GO to A4.

No
REPAIR circuit SBP28 (GN/RD or BU/RD) for an open. TEST the system for normal operation.

A4 CHECK THE BCM (Body Control Module) SUPPLY CIRCUIT

- Disconnect: BCM (Body Control Module) C2280G.

- Measure the voltage between C2280G-1, circuit SBF03 (RD), harness side and ground.





Is the voltage greater than 10 volts?

Yes
GO to A5.

No
VERIFY MEGA fuse (125A) is OK. If OK, REPAIR circuit SBF03 (RD). TEST the system for normal operation. If not OK, REFER to the Wiring Diagrams to identify the possible cause of the short circuit. TEST the system for normal operation. [1][2]Diagrams By Number

A5 CHECK THE BCM (Body Control Module) ELECTRICAL CONNECTORS

- Check the BCM (Body Control Module) electrical connectors C2280A and C2280G for:
- corrosion

- damaged pins

- pushed-out pins


- Repair any identified concerns.

- Connect the BCM (Body Control Module) connectors and make sure they are seated correctly.

- Operate the system and verify the concern is still present.

Is the concern still present?

Yes
INSTALL a new BCM (Body Control Module). TEST the system for normal operation.

No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.