Pinpoint Tests BZ: DTC U300A:62 Or U300A:64
Instrumentation, Message Center and Warning Chimes
Pinpoint Test BZ: DTC U300A:62 Or U300A:64
Refer to Wiring Diagram Set 60 (Fusion/Milan/MKZ, Fusion Hybrid, Milan Hybrid, MKZ Hybrid), Instrument Cluster for schematic and connector information. Diagrams By Number
Normal Operation
With the ignition switch in the START or RUN position, the Instrument Panel Cluster (IPC) receives a RUN/START voltage input 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
- IPC
PINPOINT TEST BZ: 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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BZ1 RETRIEVE THE RECORDED DTCs FROM THE IPC SELF-TEST
- Check for recorded DTCs from the IPC self-test.
- Is DTC U300A:62 recorded?
Yes
GO to BZ2.
No
GO to BZ3.
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BZ2 CHECK THE IPC VOLTAGE SUPPLY
- Ignition OFF.
- Disconnect: IPC C220 .
- Measure the voltage between the IPC C220-20, circuit CBP29 (WH/VT), harness side and the IPC C220-5, circuit GD116 (BK/VT), harness side.
- Ignition ON.
- Measure the voltage between the IPC C220-20, circuit CBP29 (WH/VT), harness side and the IPC C220-5, circuit GD116 (BK/VT), harness side.
- Place the ignition in the START position.
- Measure the voltage between the IPC C220-20, circuit CBP29 (WH/VT), harness side and the IPC C220-5, circuit GD116 (BK/VT), harness side.
- Is the voltage 0 volts in the OFF position and greater than 10 volts in the RUN and START positions?
Yes
GO to BZ3.
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 of the circuit short. Diagrams By Number
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BZ3 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 BZ4.
No
REFER to Steering Column Switches Testing and Inspection to diagnose the ignition outputs to the SJB.
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BZ4 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 DTC U300A:64 still present?
Yes
INSTALL a new SJB. REFER to Multifunction Electronic Modules Service and Repair. 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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