B2844

Steering Column Switches

Pinpoint Test F: DTCs B2844 and U2472

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

Normal Operation

The Smart Junction Box (SJB) contains several inputs that monitor the voltage outputs from the ignition switch. The SJB (Smart Junction Box) uses these inputs to determine the ignition switch position and then sends that information to various modules over the Medium Speed Controller Area Network (MS-CAN).

- DTC B2844 (Ignition Fault)- If the SJB (Smart Junction Box) receives an invalid ignition state or cannot detect the ignition switch state during normal operation, DTC B2844 will be set.

- DTC U2472 (Unexpected Ignition State)- If the SJB (Smart Junction Box) does not receive the ignition RUN signal or any ignition switch signal during the SJB (Smart Junction Box) self-test, DTC U2472 will be set.

This pinpoint test is intended to diagnose the following:

- Wiring, terminals or connectors

- Ignition switch

- SJB (Smart Junction Box)

PINPOINT TEST F : DTCs B2844 AND U2472

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

F1 RETRIEVE THE DTCs

- Connect the scan tool.

- Ignition ON.

- Carry out the on-demand self test for the SJB (Smart Junction Box). Retrieve and record any DTCs.

Is DTC U2472 present?

Yes
GO to F2.

No
For DTC B2844, GO to Pinpoint Test C. Pinpoint Test C: No Power in RUN

For DTC B2A20, GO to Pinpoint Test E. Pinpoint Test E: DTC B2A20

For all other SJB (Smart Junction Box) DTCs, REFER to Body Control Systems.

F2 CHECK THE IGNITION SWITCH

- Ignition OFF.

- Disconnect: Ignition Switch C250.

- Carry out the Ignition Switch Component Test.

Is the ignition switch OK?

Yes
GO to F3.

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

F3 CHECK THE IGNITION ACC/RUN CIRCUITS FOR A SHORT TO VOLTAGE

- Disconnect: SJB (Smart Junction Box) Fuse 43 (10A).

- Disconnect: SJB (Smart Junction Box) Fuse 45 (5A).

- Disconnect: SJB (Smart Junction Box) C2280B.

- Disconnect: Run/Start Relay.

- Measure the voltage between ground and SJB (Smart Junction Box) :
- SJB (Smart Junction Box) fuse 43 (10A), circuit CDC33 (VT/GN), input side.

- SJB (Smart Junction Box) fuse 45 (5A), circuit CDC33 (VT/GN), input side.

- C2280B-45, circuit CDC34 (WH/OG), harness side.






Is any voltage present?

Yes
REPAIR the affected circuit(s). CLEAR the DTC. REPEAT the self-test.

No
GO to F4.

F4 CHECK THE SJB (Smart Junction Box) FOR NORMAL OPERATION

- Check SJB (Smart Junction Box) connectors C2280A and C2280B for:
- corrosion.
- pushed-out pins.
- spread terminal.


- Connect: SJB (Smart Junction Box) C2280A.

- Connect: SJB (Smart Junction Box) C2280B.

- Make sure the connectors are seated 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). CLEAR the DTC. REPEAT the self-test.

No
The system is operating correctly at this time. Concern may have been caused by a loose or corroded connector.