Pinpoint Test F: DTCs B2844 and U2472
Steering Column Switches
Pinpoint Tests
Pinpoint Test F: DTCs B2844 and U2472
Refer to Wiring Diagram Set 13, Power Distribution/SJB for schematic and connector information. Diagrams By Number
Normal Operation
The ignition switch receives fused battery voltage from Smart Junction Box (SJB) fuse 16 (15A) along circuit SBP16 (VT/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 SJB
- RUN - Power on circuit CDC34 (WH/OG) and CDC33 (VT/GN) to the SJB and Battery Junction Box (BJB)
- START - Power on circuit CDC35 (BU/WH) to the PCM and the One-Touch Integrated Start (OTIS) diode in the BJB. From the OTIS diode, the voltage is sent to the SJB, the PCM and the starter relay in the BJB along circuit CE336 (GN/WH).
The SJB continually monitors the ignition switch position and will set DTCs when certain conditions exist.
- DTC B2844 (Ignition Fault) - If the SJB 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 on-demand self test, the SJB 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
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.
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F1 CHECK THE IGNITION SWITCH
- Ignition OFF.
- Carry out the ignition switch component test.
- Is the ignition switch OK?
Yes
INSPECT the connector for corrosion, pushed-out pins or spread terminals. REPAIR if necessary. If the connector is OK, GO to F2.
No
INSTALL a new ignition switch. REFER to Ignition Switch Ignition Switch. CLEAR the DTCs. REPEAT the self-test.
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F2 CHECK THE ACC CIRCUIT FOR AN OPEN
- Ignition OFF.
- Disconnect: SJB C2280A.
- Disconnect: Ignition Switch C250.
- Measure the resistance between ignition switch C250-5, circuit CDC33 (VT/GN), harness side and SJB 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.
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F3 CHECK THE RUN CIRCUIT FOR AN OPEN
- Disconnect: SJB C2280E.
- Measure the resistance between ignition switch C250-1, circuit CDC34 (WH/OG), harness side and SJB C2280E-1, circuit CDC34 (WH/OG), harness side.
- Is the resistance less than 5 ohms?
Yes
GO to F4.
No
REPAIR circuit CDC34 (WH/OG). CLEAR the DTCs. REPEAT the self-test.
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F4 CHECK THE START CIRCUIT FOR AN OPEN
- Disconnect: OTIS Diode.
- Disconnect: PCM C175B.
- Measure the resistance between ignition switch C250-10, circuit CDC35 (BU/WH), harness side and:
- the OTIS diode, circuit CDC35 (BU/WH), input side.
- PCM C175B-16, circuit CDC35 (BU/WH), harness side.
- Is the resistance less than 5 ohms?
Yes
GO to F5.
No
REPAIR circuit CDC35 (BU/WH). CLEAR the DTCs. REPEAT the self-test.
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F5 CHECK THE SJB AND PCM START CIRCUIT FOR AN OPEN
- Disconnect: SJB C2280B.
- Measure the resistance between OTIS diode, circuit CE336 (GN/WH), output side and:
- SJB C2280B-32, circuit CE336 (GN/WH), harness side.
- PCM C175B-37, circuit CE336 (GN/WH), harness side.
- Is the resistance less than 5 ohms?
Yes
GO to F6.
No
REPAIR circuit CE336 (GN/WH). CLEAR the DTCs. REPEAT the self-test.
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F6 CHECK THE ACC CIRCUIT FOR A SHORT TO VOLTAGE
- Connect: SJB C2280A.
- Connect: SJB C2280B.
- Connect: SJB C2280E.
- Connect: Ignition Switch C250.
- Disconnect: SJB Fuse 45 (5A).
- Measure the voltage between SJB 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 F7.
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F7 CHECK THE RUN CIRCUIT FOR A SHORT TO VOLTAGE
- Disconnect: SJB Fuse 34 (5A).
- Ignition In ACC.
- Measure the voltage between SJB 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 F8.
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F8 CHECK THE START CIRCUIT FOR A SHORT TO VOLTAGE
- Ignition ON.
- Measure the voltage between OTIS 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 F9.
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F9 CHECK THE SJB START CIRCUIT FOR A SHORT TO VOLTAGE
- Measure the voltage between OTIS 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 F10.
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F10 CHECK FOR CORRECT SJB OPERATION
- Disconnect all SJB connections.
- Check all SJB connections for:
- corrosion.
- pushed-out pins.
- spread terminals.
- Connect all SJB 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. REFER to Body Control Systems. 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.
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