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 Smart Junction Box (SJB) contains several microprocessors that monitor the voltage outputs from the ignition switch. The SJB use these inputs to determine ignition switch position and then send that information to various modules over the High Speed Controller Area Network (HS-CAN) bus. The ignition switch is designed so that only one output (ACC, RUN or START) is sent to the SJB at a time.
- DTC B2844 (Ignition Fault) - If the SJB receives an invalid ignition RUN input or cannot receive the ignition RUN input during normal operation, DTC B2844 is set.
- DTC U2472 (Unexpected Ignition State) - If the SJB does not receive the ignition RUN signal or receives conflicting ignition switch signals while performing an on-demand self test, 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.
NOTE: Verify that battery voltage is 10 volts or greater.
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F1 CHECK THE SJB DTCs
- Review the DTCs recorded during Inspection and Verification.
- Is DTC B2A20 present?
Yes
GO to Pinpoint Test E. Pinpoint Test E: DTC B2A20
No
GO to F2.
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F2 CHECK THE IGNITION SWITCH PIDs
- Connect the scan tool.
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: DataLogger - SJB.
- Monitor the following ignition switch PIDs while cycling the ignition switch through each position:
- ECU Derived Ignition State-OFF (IGN_O_ECU)
- 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 each PID display YES when the ignition switch is moved into the corresponding position and NO when the switch is moved to another position?
Yes
The condition is not present at this time. INSPECT SJB connectors C2280A and C2280B for corrosion, spread terminals and/or pushed-out pins. REPAIR as necessary. CLEAR the DTCs. REPEAT the self-test.
No
If IGN_O_ECU displayed YES at all times, GO to Pinpoint Test A. Pinpoint Test A: No Power in All Ignition Switch Positions
If IGN_A_ECU and/or IGN_R_ECU displayed YES at all times, GO to F3.
If IGN_S_ECU displayed YES at all times, GO to Pinpoint Test E. Pinpoint Test E: DTC B2A20
If IGN_A_ECU displayed NO at all times, GO to Pinpoint Test B. Pinpoint Test B: No Power In ACC
If IGN_R_ECU displayed NO at all times, GO to Pinpoint Test C. Pinpoint Test C: No Power In RUN
If IGN_S_ECU displayed NO at all times, GO to Pinpoint Test D. Pinpoint Test D: No Power in START
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F3 ISOLATE THE SJB AND IGNITION CIRCUITS
- Disconnect: SJB C2280D.
- Disconnect: SJB C2280E.
- Measure the voltage between SJB C2280D-22, circuit CBP43 (GY) and ground.
- Measure the voltage between SJB C2280E-10, circuit CBP45 (YE) and ground.
- Is any voltage present?
Yes
REPAIR the affected circuit(s). CLEAR the DTCs. REPEAT the self-test.
No
GO to F4.
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F4 CHECK THE SJB RUN/ACC INPUTS FOR A SHORT TO VOLTAGE
- Disconnect: SJB C2280A.
- Disconnect: SJB C2280B.
- Measure the voltage between SJB C2280A-3, circuit CDC33 (VT/GN) and ground.
- Measure the voltage between SJB C2280B-45, circuit CDC34 (WH/OG) and ground.
- Is any voltage present?
Yes
GO to F5.
No
GO to F6.
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F5 CHECK THE IGNITION SWITCH FOR A SHORT TO VOLTAGE
- Disconnect: Ignition Switch C250.
- Measure the voltage between SJB C2280A-3, circuit CDC33 (VT/GN) and ground.
- Measure the voltage between SJB C2280B-45, circuit CDC34 (WH/OG) and ground.
- Is any voltage present?
Yes
REPAIR the affected circuit(s). CLEAR the DTC. REPEAT the self-test.
No
INSTALL a new ignition switch. REFER to Ignition Switch Ignition Switch. CLEAR the DTCs. REPEAT the self-test.
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F6 CHECK FOR CORRECT SJB OPERATION
- Check SJB connectors C2280A, C2280B, C2280D and C2280E for:
- corrosion.
- pushed-out pins.
- spread terminal.
- Connect: SJB C2280A.
- Connect: SJB C2280B.
- Connect: SJB C2280D.
- Connect: SJB C2280E.
- 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 Multifunction Electronic Modules Service and Repair. 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.
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