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
Microprocessors in the Smart Junction Box (SJB) continuously monitor the ignition switch state.
If DTC U2472 was set immediately following an SJB on-demand self test. Clear the SJB DTCs and repeat the self-test making sure that the ignition is in RUN. If DTC U2472 returns again, continue with Pinpoint Test F.
- DTC B2844 (Ignition Fault) - If the SJB receives an invalid ignition state (one or more ignition signals at the same time) during normal operation, DTC B2844 will be set.
- DTC U2472 (Unexpected Ignition State) - If the SJB does not receive the ignition RUN signal or cannot detect the ignition switch state during the SJB self-test, DTC U2472 will be 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 multimeter probes.
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F1 REVIEW THE SJB DTCs
- Review the DTCs retrieved during Inspection and Verification.
- Is DTC B2A20 present?
Yes
GO to Pinpoint Test E. Pinpoint Test E: DTC B2A20
No
For DTCs B2844 and U2472, GO to F2.
For all other SJB DTCs, REFER to Body Control Systems.
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F2 CHECK THE IGNITION SWITCH
- Ignition OFF.
- 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 Ignition Switch. CLEAR the DTC. REPEAT the self-test.
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F3 CHECK THE IGNITION SWITCH PIDs
- Connect: Ignition Switch C250.
- Connect the scan tool.
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: DataLogger - SJB.
- With the ignition in RUN, monitor the following PIDs:
- ECU Derived Ignition State-ACC (IGN_A_ECU)
- ECU Derived Ignition State-RUN (IGN_R_ECU)
- ECU Derived Ignition State-START (IGN_S_ECU)
- Does the IGN_R_ECU PID display Yes and do the other PIDs display No?
Yes
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. CLEAR the DTC(s). REPEAT the self-test and TEST the system for normal operation.
No
If IGN_R_ECU displays No, GO to F4.
If IGN_A_ECU displays Yes, GO to F5.
If IGN_S_ECU displays Yes, GO to Pinpoint Test E. Pinpoint Test E: DTC B2A20
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F4 CHECK THE IGNITION RUN CIRCUIT FOR AN OPEN
- Disconnect: Ignition Switch C250.
- Disconnect: SJB C2280B.
- Measure the resistance between ignition switch C250-1, circuit CE612 (GY/VT), harness side and SJB C2280B-45, circuit CE612 (GY/VT), harness side.
- Is the resistance less than 5 ohms?
Yes
GO to F6.
No
REPAIR circuit CE612 (GY/VT). CLEAR the DTC. REPEAT the self-test.
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F5 CHECK THE IGNITION ACCESSORY CIRCUITS FOR A SHORT TO VOLTAGE
- Disconnect: SJB Fuse 45 (5A).
- Using the scan tool, monitor the IGN_A_ECU PIDs:
- Does the PID display No?
Yes
Refer to the Wiring Diagrams to identify the cause of the circuit short. Diagrams By Number
No
REPAIR circuit CDC33 (VT/GN). CLEAR the DTC. TEST the system for normal operation.
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F6 CHECK THE SJB CONNECTORS
- Ignition OFF.
- Disconnect: SJB C2280A.
- Disconnect: SJB C2280B (if not previously disconnected).
- Disconnect: SJB C2280E.
- Check the connectors for:
- corrosion.
- pushed-out pins.
- spread terminal.
- Connect: All Disconnected Connectors and/or Fuses.
- 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. REFER to Body Control Systems. REPEAT the self-test, then 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.
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