Symptom:
P0622-GENERATOR FIELD NOT SWITCHING PROPERLY
When Monitored and Set Condition:
P0622-GENERATOR FIELD NOT SWITCHING PROPERLY
When Monitored: With the ignition on. Engine running.
Set Condition: When the PCM tries to regulate the generator field with no result during
monitoring.
POSSIBLE CAUSES
GENERATOR FIELD PERFORMANCE
(F142) GEN FIELD SOURCE CIRCUIT OPEN
(K20) GENERATOR FIELD DRIVER CIRCUIT SHORT TO GROUND
(K20) GENERATOR FIELD DRIVER CIRCUIT OPEN
GENERATOR FIELD COIL OPEN
GENERATOR FIELD COIL SHORTED
PCM
TEST ACTION APPLICABILITY
2 NOTE: Carefully inspect all Connectors for corrosion or spread Terminals
before continuing.
Disconnect the Generator Field harness connector.
Turn the ignition on.
With the DRBIIIt actuate the ASD Relay.
Using a 12-volt test light connected to ground, probe the (A142) ASD Relay Output
circuit.
Does the test light illuminate brightly?
Yes ! Go To 3
No ! Repair the open in the (F142) Generator Field Source circuit.ACTION A
PPLICABILITY
3 Turn the ignition off.
Disconnect the PCM harness connector.
Disconnect the Generator Field harness connector.
Measure the resistance of the (K20) Generator Field Driver circuit from PCM
harness connector to ground.
Is the resistance below 100 ohms?
Yes ! Repair the short to ground in the (K20) Generator Field Driver
circuit.
No ! Go To 4
4 Turn the ignition off.
Disconnect the PCM harness connector.
Disconnect the Generator Field harness connector.
Measure the resistance of the (K20) Generator Field Driver circuit from the PCM
harness connector to the Generator Field harness connector.
Is the resistance below 5.0 ohms?
Yes ! Go To 5
No ! Repair the open in the (K20) Generator Field Driver circuit.
5 Turn the ignition off.
Disconnect the Generator Field harness connector.
Measure the resistance across the Generator Field Terminals at the Generator.
Is the resistance above 15.0 ohms?
All
Yes ! Replace the Generator.
No ! Go To 6
6 Turn the ignition off.
Disconnect the Generator Field harness connector.
Measure the resistance across the Generator Field Terminals at the Generator.
Is the resistance below 0.5 ohms?
Yes ! Replace the Generator.
No ! Go To 7
7 NOTE: Before continuing, check the PCM harness connector terminals for
corrosion, damage, or terminal push out. Repair as necessary.
Using the schematics as a guide, inspect the wire harness and connectors. Pay
particular attention to all Power and Ground circuits.
If there are no possible causes remaining, view repair.
Repair
Replace and program the Powertrain Control Module in accordance
with the Service Information.