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

The ignition switch RUN circuit provides fused battery voltage along circuits CDC34 (WH/OG), CDC32 (BN/YE) and CDC33 (VT/GN) to the Smart Junction Box (SJB) when the key is in the RUN position.

- DTC B1555 (Ignition RUN/START Circuit Failure) - If, during normal operation the SJB detects an open or a short to ground in the RUN or START circuit, DTC B1555 will be set. The DTC will also be set if the SJB does not detect the RUN signal during the on-demand self test.

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.

-------------------------------------------------
C1 CHECK THE IGNITION SWITCH

- Carry out the Ignition Switch Component Test.

Refer to Ignition Switch for component testing.

- Is the ignition switch OK?

Yes
GO to C2.

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

-------------------------------------------------
C2 CHECK THE VOLTAGE SUPPLY TO THE SJB

- Disconnect: SJB C2280b.
- Disconnect: SJB C2280c.
- Connect: Ignition Switch C250.
- Ignition ON.
- Measure the voltage between ground and:
- SJB C2280b-17, circuit CDC32 (BN/YE), harness side.
- SJB C2280b-29, circuit CDC34 (WH/OG), harness side.
- SJB C2280c-32, circuit CDC33 (VT/GN), harness side.




- Are the voltages greater than 10 volts?

Yes
GO to C3.

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

-------------------------------------------------
C3 CHECK FOR CORRECT SJB OPERATION

- Ignition OFF.
- 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 Multifunction Electronic Modules Service and Repair. 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. CLEAR the DTCs. TEST the system for normal operation.

-------------------------------------------------