Inspection and Verification

WARNING: This page is about a different car, the 2006 Mercury Milan, 2006 Lincoln Zephyr, and 2006 Ford Fusion. However, it is still accessible from the selected car via links, so may be relevant.

Verify the customer concern.

Visually inspect for obvious signs of electrical damage.

VISUAL INSPECTION CHART 5

Electrical
Smart junction box (SJB) fuse 18 (20A) Wiring harness Connections

If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding to the next step.
If the cause is not visually evident, connect the diagnostic tool to the data link connector (DLC) and select the vehicle to be tested from the diagnostic tool menu. If the diagnostic tool does not communicate with the vehicle:
- Check that the program card is correctly installed.
- Check the connections to the vehicle.
- Check the ignition switch position.
If the diagnostic tool still does not communicate with the vehicle, GO to PINPOINT TEST P .
GO to PINPOINT TEST PC .

DIAGNOSTIC TROUBLE CODE (DTC) INDEX

DTC	Description	Source	Action
U0002	High Speed CAN Communication Bus Performance	Instrument Cluster	REPAIR all other DTCs first. CLEAR the DTCs. If DTC U0002 is still present, GO to PINPOINT TEST N .
U0020	Medium Speed CAN Communication Bus Performance	Instrument Cluster	REPAIR all other DTCs first. CLEAR the DTCs. If DTC U0020 is still present, GO to PINPOINT TEST O .
U0073	Control Module Communication Bus Off	Digital Signal Processing Module	REPAIR all other DTCs first. CLEAR the DTCs. If DTC U0073 is still present, GO to PINPOINT TEST O .
U0073	Control Module Communication Bus Off	Electronic Automatic Temperature Control (EATC) Module	REPAIR all other DTCs first. CLEAR the DTCs. If DTC U0073 is still present, GO to PINPOINT TEST O .
U0073	Control Module Communication Bus Off	Smart Junction Box (SJB)	REPAIR all other DTCs first. CLEAR the DTCs. If DTC U0073 is still present, GO to PINPOINT TEST O .
U0073	Control Module Communication Bus Off	Transmission Control Module (TCM) (6-Speed Transmission)	REPAIR all other DTCs first. CLEAR the DTCs. If DTC U0073 is still present, GO to PINPOINT TEST N .
U0073	Control Module Communication Bus Off	TCM (FNR5 Transmission)	REPAIR all other DTCs first. CLEAR the DTCs. If DTC U0073 is still present, GO to PINPOINT TEST N .
U0100	Lost Communication With ECM/PCM A	TCM (6-Speed Transmission)	REPAIR all other DTCs first. CLEAR the DTCs. If DTC U0100 is still present, CHECK voltage and ground circuits to the PCM. REFER to INTRODUCTION - GASOLINE article for additional diagnostics. If the PCM voltage and ground checks are OK, GO to PINPOINT TEST A
U0100	Lost Communication With ECM/PCM A	TCM (FNR5 Transmission)	REPAIR all other DTCs first. CLEAR the DTCs. If DTC U0100 is still present, CHECK voltage and ground circuits to the PCM. REFER to the INTRODUCTION - GASOLINE article for additional diagnostics. If the PCM voltage and ground checks are OK, GO to PINPOINT TEST A
U0121	Lost Communication With ABS Module	TCM (6-Speed Transmission)	REPAIR all other DTCs first. CLEAR the DTCs. If DTC U0121 is still present, CHECK voltage and ground circuits to the ABS module. REFER to VEHICLE DYNAMIC SYSTEMS for additional diagnostics. If the ABS module voltage and ground checks are OK, GO to PINPOINT TEST C
U0140	Lost Communication With Body Control Module	EATC	REPAIR all other DTCs first. CLEAR the DTCs. If DTC U0140 is still present, CHECK voltage and ground circuits to the SJB. REFER to MULTIFUNCTION ELECTRONIC CONTROL MODULES for additional diagnostics. If the SJB voltage and ground checks are OK, GO to PINPOINT TEST G
U0155	Lost Communication With Instrument Cluster	EATC	REPAIR all other DTCs first. CLEAR the DTCs. If DTC U0155 is still present, CHECK voltage and ground circuits to the instrument cluster. REFER to INSTRUMENT CLUSTER for additional diagnostics. If the instrument cluster voltage and ground checks are OK, GO to PINPOINT TEST F
U0246	Lost Communication with DSCM	EATC	REPAIR all other DTCs first. CLEAR the DTCs. If DTC U0246 is still present, CHECK voltage and ground circuits to the climate controlled seat module. REFER to SEATING for additional diagnostics. If the climate controlled seat module voltage and ground checks are OK, GO to PINPOINT TEST J
U1900	CAN Communication Bus Fault	Audio Unit	REPAIR all other DTCs first. CLEAR the DTCs. If DTC U1900 is still present, GO to PINPOINT TEST PC .
U1900	CAN Communication Bus Fault	Anti-Lock Brake System (ABS) Module	REPAIR all other DTCs first. CLEAR the DTCs. If DTC U1900 still present, GO to PINPOINT TEST PC .
U1900	CAN Communication Bus Fault	Driver Seat Module (DSM)	REPAIR all other DTCs first. CLEAR the DTCs. If DTC U1900 is still present, GO to PINPOINT TEST PC .
U1900	CAN Communication Bus Fault	Digital Signal Processing Module	REPAIR all other DTCs first. CLEAR the DTCs. If DTC U1900 is still present, GO to PINPOINT TEST PC .
U1900	CAN Communication Bus Fault	Instrument Cluster	REPAIR all other DTCs first. CLEAR the DTCs. If DTC U1900 is still present, GO to PINPOINT TEST PC .
U1900	CAN Communication Bus Fault	Occupant Classification Sensor	REPAIR all other DTCs first. CLEAR the DTCs. If DTC U1900 is still present, GO to PINPOINT TEST PC .
U1900	CAN Communication Bus Fault	Restraint Control Module (RCM)	REPAIR all other DTCs first. CLEAR the DTCs. If DTC U1900 is still present, GO to PINPOINT TEST PC .
U1900	CAN Communication Bus Fault	SJB	REPAIR all other DTCs first. CLEAR the DTCs. If DTC U1900 is still present, GO to PINPOINT TEST PC .
U1901	CAN Network 2 Communication Bus Fault	ABS Module	REPAIR all other DTCs first. CLEAR the DTCs. If DTC U1901 is still present, GO to PINPOINT TEST PC .
U1901	CAN Network 2 Communication Bus Fault	Instrument Cluster	REPAIR all other DTCs first. CLEAR the DTCs. If DTC U1901 is still present, GO to PINPOINT TEST PC .