DaimlerChrysler Jeep Grand Cherokee 2002, Service Manual

Page: 140 / 284

P0620-GENERATOR FIELD CONTROL MALF CHARGING VOLTS TOO LOW
When Monitored: With the engine running.
Set Condition: The ECM senses battery voltage that is 1volt or more below desired
charging voltage.
P0620-GENERATOR FIELD CONTROL MALF HIGH GENERATOR CURRENT
When Monitored: With the engine running.
Set Condition: The ECM detects a higher current than should be.
P0620-GENERATOR FIELD CONTROL MALF OPEN CIRCUIT
When Monitored: With the ignition on.
Set Condition: The ECM detects an open or short to ground on the Generator Field
Control circuit.
P0620-GENERATOR FIELD CONTROL MALF SHORT CIRCUIT
When Monitored: With the ignition on.
Set Condition: The ECM detects excessive current on the Generator Field Control circuit.
POSSIBLE CAUSES
INTERMITTENT CONDITION
GENERATOR BELT CONDITION OR TENSION
GENERATOR FIELD
GENERATOR FIELD CONTROL CIRCUIT SHORTED TO VOLTAGE
GENERATOR FIELD CONTROL CIRCUIT SHORTED TO GROUND
GENERATOR FIELD CONTROL CIRCUIT OPEN
HIGH RESISTANCE ON THE B) SENSE CIRCUIT
HIGH RESISTANCE ON THE BATTERY(-) SENSE CIRCUIT
ENGINE CONTROL MODULE
TEST ACTION APPLICABILITY
1 NOTE: If there are any Battery Sense DTCs (P1511 or P1512) present with
this DTC, diagnose the Battery Sense DTCs first.
NOTE: Inspect the vehicle for aftermarket accessories that may exceed the
Generator capacity.
NOTE: The battery must be fully charged before continuing.
Inspect the generator belt condition and tension.
Is the generator belt in good condition and tensioned properly? All
Yes
→
Go To 2
No
→
Repair as necessary.
Perform CHARGING VERIFICATION - VER-3.
132
DRIVEABILITY - DIESEL
P0620-GENERATOR FIELD CONTROL MALF BATTERY VOLTAGE DEVI-
ATION TOO HIGH —
Continued
ProCarManuals.com