Pinpoint Test C: DTC B1555

Steering Column Switches

Pinpoint Tests

Pinpoint Test C: DTC B1555

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

Normal Operation

When placed in RUN, the ignition switch provides voltage to the Smart Junction Box (SJB) and the instrument cluster on circuit CDC34 (WH/OG). When placed in START, the ignition switch provides voltage to the SJB on circuit CDC35 (BU/WH).

- DTC B1555 (Ignition RUN/START Circuit Failure) - If the SJB detects an open circuit, a short to voltage or a short to ground on the RUN/START circuit, DTC B1555 will be set.

This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Ignition switch
- SJB



PINPOINT TEST C: DTC B1555

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

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C1 RETRIEVE DTCs


- Connect the scan tool.
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: SJB Self Test.
- Record DTCs.
- Is DTC B1363 or B1555 present?

Yes
If only DTC B1363 is present, GO to C2 .
If only DTC B1555 is present, GO to C3 .
If both DTCs are present, GO to C4 .

No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the self-test.

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C2 CHECK CIRCUIT CDC35 (BU/WH) FOR AN OPEN OR A SHORT TO GROUND


- Ignition OFF.
- Disconnect: SJB C2280c.
- Disconnect: Ignition Switch C250.
- Measure the resistance between:
- ignition switch C250-7, circuit CDC35 (BU/WH), harness side and SJB C2280c-19, circuit CDC35 (BU/WH), harness side.
- ignition switch C250-7, circuit CDC35 (BU/WH), harness side and ground.




- Are the resistances less than 5 ohms between the components and greater than 10,000 ohms to ground?

Yes
GO to C4.

No
REPAIR circuit CDC35 (BU/WH). CLEAR the DTCs. REPEAT the self-test.

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C3 CHECK CIRCUIT CDC34 (WH/OG) FOR AN OPEN OR A SHORT TO GROUND


- Ignition OFF.
- Disconnect: SJB C2280c.
- Disconnect: Ignition Switch C250.
- Measure resistance between:
- ignition switch C250-1, circuit CDC34 (WH/OG), harness side and SJB C2280c-26, circuit CDC34 (WH/OG), harness side.
- ignition switch C250-1, circuit CDC34 (WH/OG), harness side and ground.




- Are the resistances less than 5 ohms between the components and greater than 10,000 ohms to ground?

Yes
GO to C4.

No
REPAIR circuit CDC34 (WH/OG). CLEAR the DTCs. REPEAT the self-test.

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C4 CHECK THE IGNITION SWITCH


- Carry out the Ignition Switch Component Test.

- Is the ignition switch OK?

Yes
GO to C5.

No
INSTALL a new ignition switch. REFER to Ignition Switch Ignition Switch. CLEAR the DTCs. REPEAT the self-test.

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C5 CHECK FOR CORRECT SJB OPERATION


- Disconnect all the SJB connectors.
- Check for:
- corrosion.
- pushed-out pins.
- spread terminals.
- Connect all the SJB connectors and make sure they seat correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?

Yes
INSTALL a new SJB. REFER to Body Control Systems.

No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the self-test.

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