Charging System - 5.0L 32V Ti-VCT — 2016 workshop reference 4039

B5 CHECK THE VOLTAGE DROP IN THE VEHICLE GROUNDS

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

Positive Lead	Measurement / Action	Negative Lead
Generator case Charging System - 5.0L 32V Ti-VCT — original illustration 1, reference 4039Original colors & callouts · Select to enlarge		Charging System - 5.0L 32V Ti-VCT — original illustration 2, reference 4039Original colors & callouts · Select to enlarge

Positive Lead

Measurement /

Action

Negative Lead

Generator case

Charging System - 5.0L 32V Ti-VCT — original illustration 1, reference 4039Original colors & callouts · Select to enlarge

Charging System - 5.0L 32V Ti-VCT — original illustration 2, reference 4039Original colors & callouts · Select to enlarge

Is the voltage drop less than 0.5 volt?

Yes	GO to B6
No	INSPECT and REPAIR the engine ground, generator ground or the battery ground for corrosion.

B6 MONITOR THE 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 PCM PID GENVDSD to 14 volts. With the engine running at idle, measure battery and record:

Positive Lead	Measurement / Action	Negative Lead
Charging System - 5.0L 32V Ti-VCT — original illustration 3, reference 4039Original colors & callouts · Select to enlarge		Charging System - 5.0L 32V Ti-VCT — original illustration 4, reference 4039Original colors & callouts · Select to enlarge

Positive Lead

Measurement /

Action

Negative Lead

Charging System - 5.0L 32V Ti-VCT — original illustration 3, reference 4039Original colors & callouts · Select to enlarge

Charging System - 5.0L 32V Ti-VCT — original illustration 4, reference 4039Original colors & callouts · Select to enlarge

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

Yes	GO to B7
No	With automatic transmission, INSTALL a new generator. REFER to: Generator - 5.0L 32V Ti-VCT (414-02 Generator and Regulator, Removal and Installation). With manual transmission, GO to B11

Yes

GO to B7

With automatic transmission, INSTALL a new generator. REFER to: Generator - 5.0L 32V Ti-VCT (414-02 Generator and Regulator, Removal and Installation).

With manual transmission, GO to B11

B7 COMPARE THE PCM (POWERTRAIN CONTROL MODULE) SUPPLY VOLTAGE (VPWR) PID (PARAMETER IDENTIFICATION) TO BATTERY VOLTAGE

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

Positive Lead

Measurement /

Action

Negative Lead

Source reference 4039

2016 Mustang workshop publication supplied to Mustang Atlas. Original technical text and illustrations; HTML formatting by Mustang Atlas. Source page numbering is retained for traceability. Follow the configuration, revision, warnings, and cross-references in the material. About this edition.