Checking Charging System Operation - Diesel

Test 1:

Tests 2 - 5:

Tests 6 - 9:

Tests 10 - 11:

SYMPTOM
CHECKING THE CHARGING SYSTEM OPERATION - DIESEL

TEST NOTE:
This symptom is diagnosed using the test P1682-CHARGING SYSTEM VOLTAGE TOO LOW - DIESEL.

WHEN MONITORED
With the engine running.

SET CONDITION
The voltage at PCM cavity C1-22 is 0.5 volt or more below the target charging voltage for at least 3 seconds.

POSSIBLE CAUSES
- Check for cycling voltage on the generator field driver circuit
- Intermittent condition
- Generator belt condition or tension
- High resistance in the fused B+ circuit to the PCM
- Generator field driver circuit shorted to voltage
- Generator fused B+ circuit high resistance
- ASD relay output circuit open
- Generator ground circuit high resistance
- Generator field driver circuit open
- Powertrain control module