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Home >> Ford Truck >> 2012 >> Explorer FWD L4-2.0L Turbo >> Repair and Diagnosis >> Starting and Charging >> Charging System >> Testing and Inspection >> Pinpoint Tests >> Diagnostic Routine B

Diagnostic Routine B




Diagnostic Routine B

Diagnostic Overview

System Voltage Low or Battery is Discharged

Refer to Wiring Diagram Set 12 for schematic and connector information Electrical Diagrams.

Normal Operation and Fault Conditions

With the engine running, the charging system supplies voltage to the battery and the electrical system through the high current BJB (Battery Junction Box) and battery B+ cable. The PCM (Powertrain Control Module) monitors this voltage. If voltage drops 1.5 volts or more below the generator voltage desired, these DTCs (Diagnostic Trouble Codes) can set after 30 seconds.

DTC (Diagnostic Trouble Code) Fault Trigger Conditions






Visual Inspection and Diagnostic Pre-checks

- Inspect fusible links.

- Inspect for abnormal ignition-off current drain(s).

- Inspect the radial arm adapter.

- Inspect the battery.

- Inspect the wiring, terminals or connectors.

- Inspect for loose or corroded connections.

- Inspect high current BJB (Battery Junction Box) for loose or corroded connections.

Pinpoint Test

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.

1. CHECK BATTERY CONDITION

1. REFER to Diagnostic Routine A: Battery Condition Test Pinpoint Tests to determine if the battery can hold a charge and is OK for use.

Does the battery pass the condition test?






2. RETRIEVE PCM (Powertrain Control Module) DTCs (Diagnostic Trouble Codes)

1. Using a scan tool, perform PCM (Powertrain Control Module) self test.

Is DTC (Diagnostic Trouble Code) P0620, P0625, P0626 or P065B present?






3. CHECK THE GENERATOR CONNECTIONS

1. Ignition OFF.

2. Disconnect and inspect all generator connectors.

3. 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

4. Connect the generator connectors. Make sure they seat, latch correctly and are tightened to specification. REFER to Torque Specifications .

5. Measure and record battery voltage.

6. Measure:





Is the voltage within 0.5 volt of battery voltage?






4. CHECK THE VOLTAGE DROP IN THE B+ CIRCUIT

1. Start the engine.

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





3. Carry out a wiggle test of the generator wiring and connections while measuring voltage drop.

Is the voltage drop less than 0.5 volt?






5. CHECK THE VOLTAGE DROP IN THE VEHICLE GROUNDS

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





Is the voltage drop less than 0.5 volt?






6. MONITOR THE GENERATOR VOLTAGE DESIRED (GENVDSD) PID (Parameter Identification) WHILE COMMANDED

1. Using a scan tool, view the PCM (Powertrain Control Module) PIDs (Parameter Identifications).

2. Using the active command, set PID (Parameter Identification) GENVDSD to 14 volts.

3. Monitor the PCM (Powertrain Control Module) PID (Parameter Identification) GENVDSD.

4. With the engine still running at idle, measure and record the battery voltage at the battery.

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






7. COMPARE THE SUPPLY VOLTAGE (VPWR) PID (Parameter Identification) TO BATTERY VOLTAGE

1. With the engine still running at idle, headlamps on and blower on high, measure and record the battery voltage at the battery.

2. Using a scan tool, view the PCM (Powertrain Control Module) PIDs (Parameter Identifications).

3. Monitor the PCM (Powertrain Control Module) PID (Parameter Identification) VPWR.

Does the PID (Parameter Identification) accurately display battery voltage within± 0.5 volt of the recorded battery voltage?






8. CHECK PCM (Powertrain Control Module) GROUND FOR HIGH RESISTANCE

1. Monitor PCM (Powertrain Control Module) PID (Parameter Identification) VPWR.

2. With the engine still running at idle, turn off all accessory loads, measure the battery voltage at the battery and note the PCM (Powertrain Control Module) PID (Parameter Identification) VPWR.

3. With the engine still running at idle, turn headlamps on and blower on high, measure the battery voltage at the battery and monitor the PCM (Powertrain Control Module) PID (Parameter Identification) VPWR.

Does the PID (Parameter Identification) read within± 0.5 volt with accessory loads on as compared to accessory loads off?






9. MONITOR THE SUPPLY VOLTAGE (VPWR) PID (Parameter Identification)

1. With the engine still running at idle, turn off all accessory loads, measure and record the battery voltage at the battery and monitor the PCM (Powertrain Control Module) PID (Parameter Identification) VPWR.

2. Monitor the PID (Parameter Identification) VPWR and momentarily accelerate the engine to WOT (Wide Open Throttle) and release. Repeat this step 4-5 times while continuing to monitor the PID (Parameter Identification).

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






10. CHECK FOR CORRECT PCM (Powertrain Control Module) OPERATION

1. Ignition OFF.

2. Disconnect and inspect all PCM (Powertrain Control Module) connectors.

3. 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

4. Reconnect the PCM (Powertrain Control Module) and generator connectors. Make sure they seat and latch correctly.

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

Is the concern still present?





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