Pinpoint Test A: No Power in All Ignition Switch Positions

Steering Column Switches

Pinpoint Test A: No Power in All Ignition Switch Positions

Refer to Wiring Diagram Set 13, Power Distribution/SJB for schematic and connector information [1][2]Diagrams By Number.

Normal Operation

The ignition switch receives fused battery voltage from Smart Junction Box (SJB) fuse 27 (20A) along circuit SPB27 (BU/RD), this voltage is then sent to the SJB (Smart Junction Box) and the Battery Junction Box (BJB) for various systems depending on the ignition switch position. The ignition switch has 4 possible positions:

- OFF, voltage is sent to the SJB (Smart Junction Box) for the key-in ignition system. to diagnose any key-in ignition concerns.

- ACC, voltage is sent to the SJB (Smart Junction Box) run/accessory bus along circuit CDC33 (VT/GN).

- RUN, voltage is sent along circuit CE612 (GY/VT) to the:
- SJB (Smart Junction Box) run/start bus

- SJB (Smart Junction Box) internal microprocessor

- start diode

- BJB (Battery Junction Box) fuse 39 (5A)

- BJB (Battery Junction Box) fuse 45 (5A)


- START, voltage is sent to the SJB (Smart Junction Box) start bus along circuit CDC35 (BU/WH).

This pinpoint test is intended to diagnose the following:

- Fuse(s)

- Wiring, terminals or connectors

- Ignition switch

- SJB (Smart Junction Box)

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 multimeter probes.

A1 CHECK THE VOLTAGE AT THE IGNITION SWITCH

- Ignition OFF.

- Disconnect: Ignition Switch C250.

- Measure the voltage between ignition switch C250-4, circuit SBP27 (BU/RD), harness side and ground.





Is the voltage greater than 10 volts?

Yes
GO to A3.

No
VERIFY Smart Junction Box (SJB) fuse 27 (20A) is OK. If not OK, REFER to the Wiring Diagrams to identify the possible causes of the circuit short [1][2]Diagrams By Number. If OK, GO to A2.

A2 CHECK THE IGNITION SWITCH INPUT CIRCUIT FOR AN OPEN

- Disconnect: SJB (Smart Junction Box) C2280A.

- Measure the resistance between ignition switch C250-4, circuit SBP27 (BU/RD), harness side and SJB (Smart Junction Box) C2280A-14, circuit SBP27 (BU/RD), harness side.





Is the resistance less than 5 ohms?

Yes
GO to A3.

No
REPAIR circuit SBP27 (BU/RD). TEST the system for normal operation.

A3 CHECK THE IGNITION SWITCH

- Carry out the Ignition Switch Component Test.

Is the ignition switch OK?

Yes
GO to A4.

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

A4 CHECK FOR CORRECT SJB (Smart Junction Box) OPERATION

- Check SJB (Smart Junction Box) C2280A for:
- corrosion.

- pushed-out pins.

- spread terminals.


- Connect: Ignition Switch C250.

- Connect: SJB (Smart Junction Box) C2280A.

- Make sure the connectors seat correctly, then operate the system and verify the concern is still present.

Is the concern still present?

Yes
INSTALL a new SJB (Smart Junction Box). REPEAT the self-test.

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