Pinpoint Test J: P2D57

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Refer to Charging System for schematic and connector information.

Normal Operation and Fault Conditions

With the engine running, the charging system supplies voltage to the battery and the vehicle electrical system through the high current BJB and battery B+ cable. The PCM monitors this B+ voltage through PCM VPWR circuits. If the charging system voltage drops 1.5 volts or more below the generator voltage desired (GENVDSD), the DTC sets and the charging system MIL illuminates after 30 seconds.

The PCM monitors the generator output via the generator monitor (GENMON2) circuit. The PCM uses the generator command (GENCOM2) circuit to command the generator to either increase or decrease output. If the GENCOM2 circuit (generator control circuit) or the "A" sense circuit are open or shorted to ground, the PCM will not be able to control the generator output. When the engine speed is greater than 2, 000 rpm, the generator defaults to a steady voltage output of 13.5 volts and the PCM sends a request to the IPC to illuminate the charging system warning indicator. A GENCOM circuit fault can be confirmed by viewing the PCMPID generator command line fault (GENCMD_LF2) (YES status indicator fault).

DTC Fault Trigger Conditions

DTC	Description	Fault Trigger Condition
PCM P2D57:00	Generator 'B' Control Circuit Range/Performance: No Sub Type Information	The PCM sets this DTC if the secondary generator GENCOM circuit, "B" sense circuit, or B+ circuit is open or shorted to ground.

Possible Causes

Fuses
Secondary Generator
Generator
PCM
Wiring, terminals or connectors

Visual Inspection and Pre-checks

Inspect the FEAD system. REFER to: ACCESSORY DRIVE - 3.5L DURATEC (202KW 275PS) or Refer to: ACCESSORY DRIVE - 3.5L ECOBOOST (235KW 320PS)
Inspect for abnormal ignition-off current drain(s).
Inspect the battery.
Inspect the high current BJB for loose, damaged or corroded connections.
Verify high current BJB fuse 11 (250A).

J1 PERFORM INSPECTION AND VERIFICATION
- Perform Inspection and Verification procedure in this article.
Was an obvious cause for an observed or reported concern found?

Yes CORRECT the cause as necessary.

No GO to J2

J2 RETRIEVE DIAGNOSTIC TROUBLE CODES (DTCS)

Using a diagnostic scan tool, perform the PCM self-test.

Is DTC P065B, P065C, U012D or U042E present?

Yes	If P065B and P065C are present, GO to Pinpoint Test B If P065B is present without P065C, INSTALL a new generator. REFER to: Generator - 3.5L Duratec (202kW/275PS) . If U012D or U042E is present, GO to Pinpoint Test F

GO to J3

J3 CHECK THE GENERATOR CONNECTIONS

Ignition OFF.

Disconnect all of the generator connectors and inspect for:
- 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 generator connectors. Make sure they seat and latch correctly.

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:

Positive Lead	Measurement / Action	Negative Lead
C1251A Pin 1	Courtesy of FORD MOTOR COMPANY	Ground

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

Yes

GO to J4

TIGHTEN or INSTALL a new generator B+ nut as needed. REFER to: Generator - 3.5L Duratec (202kW/275PS)
(414-02 Generator and Regulator, Removal and Installation). VERIFY high current BJB fuse 11 (250A) is OK. If OK, REPAIR the circuit. If not OK, REFER to the appropriate Wiring Diagrams article to identify the possible causes of the circuit short.

J4 CHECK THE VOLTAGE DROP IN THE GENERATOR B+ CIRCUIT

Start the engine.

With the engine running at idle, headlamps on and blower on high, measure:

Positive Lead	Measurement / Action	Negative Lead
C1251A Pin 1	Courtesy of FORD MOTOR COMPANY	Courtesy of FORD MOTOR COMPANY

Perform a wiggle test of the generator wiring and connections while measuring voltage drop.

Is the voltage drop less than 0.5 volt?

Yes

GO to J5

No	INSPECT and REPAIR any corrosion in the generator B+ circuit or positive battery cable connections.

J5 CHECK THE VOLTAGE DROP IN THE VEHICLE GROUNDS

With the engine still running at idle, headlamps on and heater blower on high, measure:

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

Is the voltage drop less than 0.5 volt?

Yes

GO to J6

No	INSPECT and REPAIR the engine ground, generator ground or the battery ground for corrosion.

J6 MONITOR THE SECONDARY GENERATOR VOLTAGE DESIRED (GENVDSD) PID (PARAMETER IDENTIFICATION) WHILE COMMANDED

Using a diagnostic scan tool, view the PCM GENVDSD PID.

Using a diagnostic scan tool active command, set the PCMPID GENVDSD to 14 volts.

With the engine still running at idle, measure battery and record:

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

Is the recorded battery voltage within +/-0.5 volt of the PID '

Yes

GO to J7

GO to J11

J7 COMPARE THE SUPPLY VOLTAGE (VPWR) PID (PARAMETER IDENTIFICATION) TO BATTERY VOLTAGE

With the engine still running at idle, headlamps on and blower on high, measure and record:

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

Access the PCM and monitor the VPWR (V) PID.

Does the PID accurately display battery voltage within +/-0.5 volt of the recorded battery voltage?

Yes

GO to J8

No	REPAIR high resistance or loose connections in the affected PCM power circuit(s).

J8 CHECK PCM (POWERTRAIN CONTROL MODULE) VOLTAGE SUPPLY CIRCUITS

Ignition OFF.

Disconnect PCM C1551B.

Ignition OFF.

Measure and record:

Ignition ON.

Measure and record:

Positive Lead	Measurement / Action	Negative Lead
C1551B Pin 1	Courtesy of FORD MOTOR COMPANY	Ground
C1551B Pin 2	Courtesy of FORD MOTOR COMPANY	Ground
C1551B Pin 16	Courtesy of FORD MOTOR COMPANY	Ground

Are the voltages within 0.5 volt of the recorded battery voltage?

Yes	REMOVE the fused jumper wire and INSTALL BJBPCM power relay GO to J9

No	REPAIR the affected circuit(s).

J9 CHECK PCM (POWERTRAIN CONTROL MODULE) GROUND FOR HIGH RESISTANCE

NOTE: Measure battery voltage at the battery.

With the engine still running at idle, turn off all accessory loads, measure and record:

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

Access the PCM and monitor the VPWR (V) PIDand record.

With the engine still running at idle, turn headlamps ON and blower on HIGH.

Measure and record:

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

Using a diagnostic scan tool, view PCMPID VPWR and record.

Does the PID read within +/-0.5 volt of battery voltage with accessory loads on and off?

Yes

GO to J10

No	REPAIR the affected PCM ground circuit(s).

J10 MONITOR THE SUPPLY VOLTAGE (VPWR) PID (PARAMETER IDENTIFICATION)

NOTE: Measure battery voltage at the battery.

With the engine still running at idle, turn off all accessory loads.

Measure and record:

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

Access the PCM and monitor the VPWR (V) PIDand record.

Momentarily accelerate the engine to Wide Open Throttle (WOT) and release. Repeat this step 4-5 times while continuing to monitor the PID.

Does the PID stay within 0.5 volt of the recorded battery voltage when the engine Revolutions Per Minute (RPM) are increased?

Yes	The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. INSPECT and REPAIR any connector or pin issues found. If no connector or pin issues are found, PERFORM the battery drain test. REFER to: Battery Drain Check .

GO to J11

J11 CHECK GENERATOR CLUTCH OPERATION
- Ignition OFF.
- Perform the generator clutch component test. GO to Pinpoint Test H
Is the generator clutch OK?

Yes INSTALL a new generator. REFER to: Generator - 3.5L Duratec (202kW/275PS) .

No INSTALL a new generator clutch. REFER to: Generator - 3.5L Duratec (202kW/275PS) .

J12 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 TSB address this concern, REFER to: Engine .

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