Pinpoint Tests BH: DTC U300A:62 Or U300A:64
Instrumentation, Message Center and Warning Chimes
Pinpoint Tests
Pinpoint Test BH: DTC U300A:62 Or U300A:64
Refer to Wiring Diagram Set 60, Instrument Cluster for schematic and connector information. Diagrams By Number
Normal Operation
With the ignition in the START or RUN mode, the Instrument Panel Cluster (IPC) receives its hardwired voltage from the Smart Junction Box (SJB). The IPC also receives a networked ignition status from the SJB over the Medium Speed Controller Area Network (MS-CAN) communication bus.
- DTC U300A:62 (Ignition Switch: Signal Compare Failure) - the IPC compares the networked input with the hardwired input and sets DTC U300A:62 in continuous memory and on-demand if a discrepancy is detected.
- DTC U300A:64 (Ignition Switch: Signal Plausibility Failure) - the IPC monitors the messaged START status and sets DTC U300A:64 in continuous memory and on-demand if the IPC detects a START input for 15 seconds. Once the fault condition is detected, the IPC retains limited functionality for 15 seconds then returns to full functionality.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- SJB
PINPOINT TEST BH: DTC U300A:62 OR U300A:64
NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.
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BH1 CHECK THE IPC RUN/START VOLTAGE SUPPLY
- Ignition OFF.
- Disconnect: IPC C220.
- Measure the voltage between the IPC C220-20, circuit CBP29 (WH/VT), harness side and ground.
- Ignition ON.
- Measure the voltage between the IPC C220-20, circuit CBP29 (WH/VT), harness side and ground.
- Place the ignition in the START mode.
- Measure the voltage between the IPC C220-20, circuit CBP29 (WH/VT), harness side and ground.
- Is the voltage 0 volts in the OFF position and greater than 10 volts in the RUN and START modes?
Yes
GO to BH2.
No
VERIFY the SJB fuse 29 (5A) is OK. If OK, REPAIR the circuit for an open. TEST the system for normal operation. If not OK, REFER to the Wiring Diagrams to identify the possible causes for the circuit short. Diagrams By Number
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BH2 CHECK THE SJB INPUT PIDs FROM THE IGNITION SWITCH
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: SJB DataLogger.
- Select the SJB PIDs ignition ACC (IGN_A_ECU), ignition OFF (IGN_O_ECU), ignition RUN (IGN_R_ECU), and ignition START (IGN_S_ECU). Monitor the ignition PIDs while switching the ignition from ACC, OFF, RUN and START.
- Do the SJB PIDs match the ignition mode?
Yes
GO to BH3.
No
REFER to Steering Column to diagnose the ignition outputs to the SJB.
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BH3 CHECK THE IPC DTCs
- Enter the following diagnostic mode on the scan tool: IPC Self-Test.
- Repeat the IPC self-test. Clear the DTCs.
- Is DTC U300A:62 or U300A:64 still present?
Yes
INSTALL a new SJB. REFER to Body Control Systems. CLEAR the DTCs. REPEAT the self-test.
If the DTC is still present, INSTALL a new IPC. REFER to Instrument Panel Cluster (IPC) Instrument Panel Cluster (IPC). TEST the system for normal operation.
No
The system is operating correctly at this time. The DTC may have been set due to high network traffic or an intermittent fault condition.
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