Pinpoint Test F: DTCs B2844 and U2472 - Vehicles With an Ignition Switch

Steering Column Switches

Pinpoint Test F: DTCs B2844 and U2472 - Vehicles With an Ignition Switch

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

Normal Operation

The Battery Junction Box (BJB) receives battery voltage along circuit SDC02 (RD) and distributes this voltage to various fuses. The ignition switch receives fused battery voltage from BJB (Battery Junction Box) fuse 27 (20A) along circuit SBP27 (BU/RD). The ignition switch then sends that voltage out to various systems depending on ignition switch position. The ignition switch has 4 possible states:

- OFF

- ACC- Power on circuit CDC33 (VT/GN) to the Smart Junction Box (SJB)

- RUN- Power on circuit CDC01 (GN/VT) and CDC33 (VT/GN) to the SJB (Smart Junction Box) and BJB (Battery Junction Box)

- START- Power on circuit CDC35 (BU/WH) to the PCM and the One-Touch Integrated Start (OTIS) diode in the BJB (Battery Junction Box). From the OTIS (One-Touch Integrated Start) diode, the voltage is sent to the SJB (Smart Junction Box), the PCM and the starter relay in the BJB (Battery Junction Box) along circuit CE336 (GN/WH).

The SJB (Smart Junction Box) continually monitors the ignition switch position and will set DTCs when certain conditions exist.

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

- DTC U2472 (Unexpected Ignition State)- If during the SJB (Smart Junction Box) on-demand self test, the SJB (Smart Junction Box) does not receive the ignition RUN signal or any ignition switch signal, DTC U2472 is 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 - VEHICLES WITH AN IGNITION SWITCH

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 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 F2.

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

F2 CHECK THE IGNITION ACC CIRCUIT FOR AN OPEN

- Ignition OFF.

- Disconnect: SJB (Smart Junction Box) C2280A.

- Measure the resistance between ignition switch C250-6, circuit CDC33 (VT/GN), harness side and SJB (Smart Junction Box) C2280A-3, circuit CDC33 (VT/GN), harness side.





Is the resistance less than 5 ohms?

Yes
GO to F3.

No
REPAIR circuit CDC33 (VT/GN). CLEAR the DTCs. REPEAT the self-test.

F3 CHECK THE IGNITION ACC CIRCUIT FOR A SHORT TO GROUND

- Measure the resistance between ignition switch C250-6, circuit CDC33 (VT/GN), harness side and ground.





Is the resistance greater than 10,000 ohms?

Yes
GO to F4.

No
REPAIR circuit CDC33 (VT/GN). CLEAR the DTCs. REPEAT the self-test.

F4 CHECK THE IGNITION RUN CIRCUIT FOR AN OPEN

- Disconnect: SJB (Smart Junction Box) C2280B.

- Disconnect: Run/Start Relay.

- Measure the resistance between ignition switch C250-1, circuit CDC01 (GN/VT), harness side and SJB (Smart Junction Box) C2280B-45, circuit CBB36 (BU/BN), harness side.





Is the resistance less than 5 ohms?

Yes
GO to F5.

No
REPAIR circuit CDC01 (GN/VT)/CBB36 (BU/BN). CLEAR the DTCs. REPEAT the self-test.

F5 CHECK THE IGNITION RUN CIRCUIT FOR A SHORT TO GROUND

- Measure the resistance between ignition switch C250-1, circuit CDC01 (GN/VT), harness side and ground.





Is the resistance greater than 10,000 ohms?

Yes
GO to F6.

No
REPAIR circuit CDC01 (GN/VT)/CBB36 (BU/BN). CLEAR the DTCs. REPEAT the self-test.

F6 CHECK THE IGNITION START CIRCUIT FOR AN OPEN

- Disconnect: OTIS (One-Touch Integrated Start) Diode.

- Disconnect: PCM C175B.

- Measure the resistance between ignition switch C250-7, circuit CDC35 (BU/WH), harness side and:
- the OTIS (One-Touch Integrated Start) diode, circuit CDC35 (BU/WH), input side.

- PCM C175B-9, circuit CDC35 (BU/WH), harness side.






Is the resistance less than 5 ohms?

Yes
GO to F7.

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

F7 CHECK THE IGNITION START CIRCUIT FOR A SHORT TO GROUND

- Measure the resistance between ignition switch C250-7, circuit CDC35 (BU/WH), harness side and ground.





Is the resistance greater then 10,000 ohms?

Yes
GO to F8.

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

F8 CHECK THE PCM START CIRCUIT FOR AN OPEN

- Disconnect: SJB (Smart Junction Box) C2280E.

- Measure the resistance between OTIS (One-Touch Integrated Start) diode, circuit CE336 (GN/WH), output side and:
- SJB (Smart Junction Box) C2280E-8, circuit CE336 (GN/WH), harness side.

- PCM C175B-35, circuit CE336 (GN/WH), harness side.






Is the resistance less than 5 ohms?

Yes
GO to F9.

No
REPAIR circuit CE336 (GN/WH). CLEAR the DTCs. REPEAT the self-test.

F9 CHECK THE PCM START CIRCUIT FOR A SHORT TO GROUND

- Measure the resistance between OTIS (One-Touch Integrated Start) diode, circuit CE336 (GN/WH), output side and ground.





Is the resistance greater than 10,000 ohms?

Yes
GO to F10.

No
REPAIR circuit CE336 (GN/WH). CLEAR the DTCs. REPEAT the self-test.

F10 CHECK THE IGNITION ACC CIRCUIT FOR A SHORT TO VOLTAGE

- Connect: SJB (Smart Junction Box) C2280A.

- Connect: SJB (Smart Junction Box) C2280B.

- Connect: Ignition Switch C250.

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

- Measure the voltage between SJB (Smart Junction Box) fuse 45 (5A) input side, circuit CDC33 (VT/GN) and ground.





Is any voltage present?

Yes
REPAIR circuit CDC33 (VT/GN). CLEAR the DTCs. REPEAT the self-test.

No
GO to F11.

F11 CHECK THE IGNITION RUN CIRCUIT FOR A SHORT TO VOLTAGE

- Disconnect: SJB (Smart Junction Box) Fuse 34 (5A).

- Ignition In ACC.

- Measure the voltage between SJB (Smart Junction Box) fuse 34 (5A) input side, circuit CDC34 (WH/OG) and ground.





Is any voltage present?

Yes
REPAIR circuit CDC34 (WH/OG). CLEAR the DTCs. REPEAT the self-test.

No
GO to F12.

F12 CHECK THE IGNITION START CIRCUIT FOR A SHORT TO VOLTAGE

- Ignition ON.

- Measure the voltage between OTIS (One-Touch Integrated Start) diode input side, circuit CDC35 (BU/WH) and ground.





Is any voltage present?

Yes
REPAIR circuit CDC35 (BU/WH). CLEAR the DTCs. REPEAT the self-test.

No
GO to F13.

F13 CHECK THE PCM START CIRCUIT FOR A SHORT TO VOLTAGE

- Measure the voltage between OTIS (One-Touch Integrated Start) diode output side, circuit CE336 (GN/WH) and ground.





Is any voltage present?

Yes
REPAIR circuit CE336 (GN/WH). CLEAR the DTCs. REPEAT the self-test.

No
GO to F14.

F14 CHECK FOR CORRECT SJB (Smart Junction Box) OPERATION

- Disconnect all SJB (Smart Junction Box) connections.

- Check all SJB (Smart Junction Box) connections for:
- corrosion.
- pushed-out pins.
- spread terminals.


- Connect all SJB (Smart Junction Box) connections and make sure they are seated correctly.

- 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 DTCs. TEST the system for normal operation.

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