Pinpoint Test H : DTC P0625, P0626

WARNING: This page is about a different car, the 2018 Lincoln Navigator. However, it is still accessible from the selected car via links, so may be relevant.

H1 PERFORM INSPECTION AND VERIFICATION
- Perform Inspection and Verification procedure in this information.
Was an obvious cause for an observed or reported concern found?

Yes REPAIR as necessary.

No GO to H2

H2 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
C102B-1	Courtesy of FORD MOTOR COMPANY	Ground

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

Yes

GO to H3

No	TIGHTEN or INSTALL a new generator B+ nut as needed. REFER to: Generator . VERIFY high current BJB MEGA fuse (300A) is OK. If OK, REPAIR the circuit. If not OK, Refer to the Wiring Diagram Information to identify the possible causes of the circuit short.

H3 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
C102B-1	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	For DTC P0625, GO to H4For DTC P0626, GO to H5

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

H4 "A" SENSE CIRCUIT LOAD TEST

NOTE: The following step uses a test light to simulate normal circuit loads. Use only the test light recommended in the Special Tools table at the beginning of this article. To avoid connector terminal damage, use the Flex Probe Kit for the test light probe connection to the vehicle. Do not use the test light probe directly on any connector.

NOTE: This step puts a load on the "A" sense circuit. If there are corroded or loose connections, loading the circuit may help show the fault. A 250-350 mA incandescent 12-volt test lamp is required for this step. This circuit cannot be loaded correctly using an LED-style test lamp.

Ignition OFF.

Disconnect Generator C102A .

Ignition ON.

Measure and record:

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

Connect the load to each circuit and measure:

Positive Lead	Measurement / Action	Negative Lead
C102A-3	Courtesy of FORD MOTOR COMPANY	Ground

Is the "A" sense voltage within ±0.5 volt of the recorded battery voltage?

Yes

GO to H5

No	VERIFY high current BJB fuse 23 (10A) is OK. If OK, REPAIR the circuit. If not OK, Refer to the Wiring Diagram Information to identify the possible causes of the circuit short.

H5 CHECK THE GENERATOR MONITOR CIRCUIT FOR A SHORT TO VOLTAGE

Ignition OFF.

Disconnect PCM C1915B .

Ignition ON.

Measure:

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

Is any voltage present?

Yes	REPAIR the circuit.

GO to H6

H6 CHECK THE GENERATOR MONITOR CIRCUIT FOR A SHORT TO GROUND

Ignition OFF.

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 H7

No	REPAIR the circuit.

H7 CHECK THE GENERATOR MONITOR CIRCUIT FOR AN OPEN

Measure:

Positive Lead	Measurement / Action	Negative Lead
C1915B-26	Courtesy of FORD MOTOR COMPANY	C102A-1

Is the resistance less than 3 ohms?

Yes

GO to H8

No	REPAIR the circuit.

H8 CHECK THE GENERATOR B+ INTERNAL RESISTANCE

Disconnect Generator C102A .

Disconnect Generator C102B .

Measure generator component side:

Positive Lead	Measurement / Action	Negative Lead
Generator B+ (Component side)	Courtesy of FORD MOTOR COMPANY	Generator case

Is the resistance greater than 25K ohms?

Yes

GO to H9

No	INSTALL a new generator. REFER to: Generator .

H9 CHECK THE COMPONENT SIDE RESISTANCE OF THE VOLTAGE REGULATOR INTERNAL CIRCUITS TO GROUND

Measure generator component side:

Positive Lead	Measurement / Action	Negative Lead
C102A-1 (Component Side)	Courtesy of FORD MOTOR COMPANY	Generator case
C102A-2 (Component Side)	Courtesy of FORD MOTOR COMPANY	Generator case
C102A-3 (Component Side)	Courtesy of FORD MOTOR COMPANY	Generator case

Are the resistances greater than 10, 000 ohms?

Yes

GO to H10

No	INSTALL a new generator. REFER to: Generator .

H10 COMPARE THE GENMON PID (PARAMETER IDENTIFICATION) AND THE GENCMD PID (PARAMETER IDENTIFICATION)

Connect PCM C1915B .

Connect:

Positive Lead	Measurement / Action	Negative Lead
C102A-1	Courtesy of FORD MOTOR COMPANY	C102A-2

Start the engine.

Using a diagnostic scan tool, view PCM Parameter Identifications (PIDs).

Using the active command, set the PID GENVDSD to 14-volts.

Monitor the PCM Parameter Identifications (PIDs) GENMON and GENCMD.

Perform a wiggle test of the generator wiring and connections.

Do the Parameter Identifications (PIDs) read within 5% of each other?

Yes	REMOVE the fused jumper wire. INSTALL a new generator. REFER to: Generator .

No	REMOVE the fused jumper wire. GO to H11

H11 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 -- NAVIGATOR . .

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.