Pinpoint Test D: No Power in START

Steering Column Switches

Pinpoint Test D: No Power in START

Normal Operation

When placed in the START position, the ignition switch provides fused ignition voltage to the Smart Junction Box (SJB) through circuits CDC34 (WH/OG) and CDC35 (BU/WH).

This pinpoint test is intended to diagnose the following:

- Wiring, terminals or connectors

- SJB (Smart Junction Box)

- Ignition switch

PINPOINT TEST D : NO POWER IN START

D1 CHECK THE IGNITION SWITCH

- Carry out the Ignition Switch- Electrical Component Test.

Does the ignition switch test OK?

Yes
GO to D2.

No
INSTALL a new ignition switch. REFER to Ignition Switch Service and Repair. TEST the system for normal operation.

D2 CHECK THE SJB (Smart Junction Box) START INPUTS FOR AN OPEN

- Disconnect: Ignition Switch C250.

- Disconnect: SJB (Smart Junction Box) C2280B.

- For all vehicles, measure the resistance between ignition switch C250-1, circuit CDC34 (WH/OG), harness side and SJB (Smart Junction Box) C2280B-45, circuit CDC34 (WH/OG), harness side.





- For diesel engine vehicles only, measure the resistance between ignition switch C250-5, circuit CDC35 (BU/WH), harness side and SJB (Smart Junction Box) C2280B-32, circuit CE336 (GN/WH), harness side.





Is the resistance less than 5 ohms?

Yes
GO to D3.

No
REPAIR the affected circuit(s). TEST the system for normal operation.

D3 CHECK THE RUN/START RELAY INPUT FOR AN OPEN

- Disconnect: Run/Start Relay.

- For all vehicles except stripped chassis, measure the resistance between ignition switch C250-1, circuit CDC34 (WH/OG), harness side and run/start relay cavity 1, circuit CDC34 (WH/OG).





- For stripped chassis vehicles, measure the resistance between ignition switch C250-1, circuit CDC34 (WH/OG), harness side and run/start relay cavity 1, circuit CDC34 (WH/OG).





Is the resistance less than 5 ohms?

Yes
GO to D4
No
REPAIR circuit CDC34 (WH/OG). TEST the system for normal operation.

D4 CHECK THE START CIRCUITS FOR AN OPEN

- Disconnect: PCM C1551B (6.8L engine).

- Disconnect: PCM C175B (All other engines).

- Disconnect: Starter Diode.

- For vehicles with a 6.8L engine, measure the resistance between ignition switch C250-5, circuit CDC35 (BU/WH), harness side and:
- PCM C1551B-20, circuit CDC35 (BU/WH), harness side.

- starter diode, circuit CDC35 (BU/WH), input side.






- For all other vehicles, measure the resistance between ignition switch C250-5, circuit CDC35 (BU/WH), harness side and:
- PCM C175B-16, circuit CDC35 (BU/WH), harness side.

- starter diode, circuit CDC35 (BU/WH), input side.






Are the resistances less than 5 ohms?

Yes
REFER to Starting System to diagnose the starting system.

No
REPAIR circuit CDC35 (BU/WH). TEST the system for normal operation.