Pinpoint Test G: U012D, U042E

WARNING: This page is about a different car, the 2021 Ford F-150. However, it is still accessible from the selected car via links, so may be relevant.

Refer to Wiring Diagrams Charging System for schematic and connector information.

Normal Operation and Fault Conditions

The charging system supplies voltage to the battery and the vehicle electrical system through the battery B+ cable. The PCM monitors the generator output through a LIN communication circuit shared with the automatic grill shutters (AGS). The PCM uses this LIN circuit to communicate the desired voltage setpoint to the generator internal voltage regulator. The generator also uses this to communicate the generator load and error conditions to the PCM.

DTC Fault Trigger Conditions

DTC	Description	Fault Trigger Condition
PCM U012D:00	Lost Communication With Generator "A" Control Module: No Sub Type Information	Sets if the PCM does not detect communication through the LIN circuit. This can be a result of an open or short in the LIN circuit. This DTC also sets if the generator B+ circuit is open.
PCM U042E:00	Invalid Data Received From Generator "A" Control Module: No Sub Type Information	Sets when the PCM receives invalid data from the generator.

Possible Sources

Battery monitoring sensor
Generator
PCM
Active Grille Shutter
Wiring, terminals or connectors

Visual Inspection and Pre-checks

Inspect high current BJB for loose, damaged or corroded connections.
Inspect the BJB fuse 201 (300A).
Inspect the BJB fuse 25 (10A).
Inspect the FEAD belt.
Inspect the battery monitoring sensor.

NOTE: Make sure battery voltage is greater than 12.2 volts prior to and during this pinpoint test.
NOTE: Do not have a battery charger attached during vehicle testing.

G1 CHECK VEHICLE FOR PRESENCE OF GRILLE SHUTTERS
- U012D:00 and U042:00 are usually caused by wiring or water intrusion in inline connectors.
- Clear DTC's.
- Start engine.
- Run for 2 minutes.
- check for DTC's.
Did DTC's return?

Yes GO to G2

No check Connector 6L3T-14A624-AB under fuse pannel in engine compartment for signs of water intrusion.

G2 RETRIEVE PCM (POWERTRAIN CONTROL MODULE) DIAGNOSTIC TROUBLE CODES (DTCS) WITH GRILLE SHUTTER ACTUATOR DISCONNECTED
- Ignition OFF.
- Disconnect Grille Shutter Actuator C1765 and C1766.
- Ignition ON.
- Clear the DTC codes.
- Start the engine.
- Wait two mimutes, Codes will not set unless engine is running.
- Using a diagnostic scan tool, scan for DTC's.
Is DTC U0284 or U0046 present?

Yes REFER to: Active Grille Shutter .

No GO to G3

G3 COMPARE THE GENERATOR B+ CIRCUIT TO BATTERY VOLTAGE

Measure and record:

Positive Lead	Measurement / Action	Negative Lead
Courtesy of FORD MOTOR COMPANY	Courtesy of FORD MOTOR COMPANY	Courtesy of FORD MOTOR COMPANY

Measure: for (2.7L and 3.5L engines)

Positive Lead	Measurement / Action	Negative Lead
C102B-1	Courtesy of FORD MOTOR COMPANY	Ground

Is the voltage within 0.5 volt of the recorded battery voltage?

Yes

GO to G4

TIGHTEN or INSTALL a new generator B+ nut as needed. REFER to: Generator - 2.7L EcoBoost (238kW/324PS) . REFER to: Generator - 3.5L EcoBoost (BM) . VERIFY high current BJB fuse 201 (300A) is OK. If OK, REPAIR the circuit. If not OK, REFER to the OEM ELECTRICAL WIRING DIAGRAM INTRODUCTION to identify the possible causes of the circuit short.

G4 CHECK THE GENERATOR LIN (LOCAL INTERCONNECT NETWORK) CIRCUIT FOR A SHORT TO VOLTAGE

Ignition OFF.

Disconnect Generator (2.7L and 3.5L engines) C102A.

Disconnect PCM (2.7L engine) C1232B.

Disconnect PCM (3.5L engine) C175B.

Ignition ON.

Measure: for (2.7L and 3.5L engines)

Positive Lead	Measurement / Action	Negative Lead
C102A-1	Courtesy of FORD MOTOR COMPANY	Ground

Is any voltage present?

Yes	REPAIR the circuit.

GO to G5

G5 CHECK THE GENERATOR LIN (LOCAL INTERCONNECT NETWORK) CIRCUIT FOR A SHORT TO GROUND

Ignition OFF.

For 2.7L and 3.5L engines, Measure:

Positive Lead	Measurement / Action	Negative Lead
C102A-1	Courtesy of FORD MOTOR COMPANY	Ground

Is the resistance greater than 10, 000 ohms?

Yes

GO to G6

No	REPAIR the circuit.

G6 CHECK THE GENERATOR LIN (LOCAL INTERCONNECT NETWORK) CIRCUIT FOR AN OPEN

For 2.7L engine, Measure:

Positive Lead	Measurement / Action	Negative Lead
C102A-1	Courtesy of FORD MOTOR COMPANY	C1232B-49
C102A-1	Courtesy of FORD MOTOR COMPANY	Upper active grille shutter actuatorC1766-2
C102A-1	Courtesy of FORD MOTOR COMPANY	Lower active grille shutter actuatorC1765-2

For 3.5L engine, Measure:

Positive Lead	Measurement / Action	Negative Lead
C102A-1	Courtesy of FORD MOTOR COMPANY	C175B-49
C102A-1	Courtesy of FORD MOTOR COMPANY	Upper active grille shutter actuatorC1766-2
C102A-1	Courtesy of FORD MOTOR COMPANY	Lower active grille shutter actuatorC1765-2

Is the resistance less than 3 ohms?

Yes	INSTALL a new generator. REFER to: Generator - 2.7L EcoBoost (238kW/324PS) . REFER to: Generator - 3.5L EcoBoost (BM) . REPEAT the PCM self-test. If DTC U012D is retrieved again, GO to G7

No	REPAIR the affected circuit.

G7 CHECK FOR CORRECT PCM (POWERTRAIN CONTROL MODULE) OPERATION

Ignition OFF.

Disconnect and inspect all PCM connectors.

Repair:
- corrosion (install new connector or terminals - clean module pins)
- damaged or bent pins - install new terminals/pins
- pushed-out pins - install new pins as necessary

Reconnect the PCM connectors. Make sure they seat and latch correctly.

Operate the system and determine if the concern is still present.

Is the concern still present?

Yes

CHECK OASIS for any applicable Technical Service Bulletins (TSBs). If a TSB exists for this concern, DISCONTINUE this test and FOLLOW the TSB instructions. If no Technical Service Bulletins (TSBs) address this concern, Refer to PCM GUIDED ROUTINE TESTING
Internet Explorer version 11 or greater is required to perform this Pinpoint Test.

No	The system is operating correctly at this time. The concern may have been caused by module connections. ADDRESS the root cause of any connector or pin issues.