Pinpoint Test D: No Power in START
Steering Column Switches
Pinpoint Tests
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
- Ignition switch
PINPOINT TEST D: NO POWER IN START
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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 Ignition Switch. TEST the system for normal operation.
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D2 CHECK THE SJB START INPUTS FOR AN OPEN
- Disconnect: Ignition Switch C250.
- Disconnect: SJB C2280B.
- For all vehicles, measure the resistance between ignition switch C250-1, circuit CDC34 (WH/OG), harness side and SJB
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 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.
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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.
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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 or Starting System to diagnose the starting system.
No
REPAIR circuit CDC35 (BU/WH). TEST the system for normal operation.
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