TEST
ACTION
APPLICABILITY
3
Turn the ignition off.
Disconnect the Generator Field harness connector.
Using a 12-volt test connected to battery voltage, probe the (Z1) Gen Ground circuit
in the Generator Field harness connector.
Does the test light illuminate brightly?
All
Yes
→ Go To 4
No
→ Repair the open in the (Z1) Gen Field Ground circuit.
Perform POWERTRAIN VERIFICATION TEST VER - 3 - NGC.
4
Turn the ignition off.
Disconnect the Generator Field harness connector.
Disconnect the PCM harness connector.
Measure the voltage on the (K20) Gen Field Control circuit in the Generator Field
harness connector.
Is the voltage above 1.0 volts?
All
Yes
→ Repair the short to voltage in the (K20) Gen Field Control circuit.
Perform POWERTRAIN VERIFICATION TEST VER - 3 - NGC.
No
→ Go To 5
5
Turn the ignition on.
Disconnect the Generator Field harness connector.
Disconnect the PCM harness connector.
Measure the resistance between ground and the (K20) Gen Field Control circuit in
the Generator Field harness connector.
Is the resistance below 100 ohms?
All
Yes
→ Repair the (K20) Gen Field Control circuit for a short to ground.
Perform POWERTRAIN VERIFICATION TEST VER - 3 - NGC.
No
→ Go To 6
6
Turn the ignition off.
Disconnect the Generator Field harness connector.
Disconnect the PCM harness connector.
CAUTION: DO NOT PROBE THE PCM HARNESS CONNECTORS. PROBING
THE PCM HARNESS CONNECTORS WILL DAMAGE THE PCM TERMI-
NALS RESULTING IN POOR TERMINAL TO PIN CONNECTION. INSTALL
MILLER SPECIAL TOOL #8815 TO PERFORM DIAGNOSIS.
Measure the resistance of the (K20) Gen Field Control circuit from the Generator
Field harness connector to the appropriate terminal of the special tool #8815.
Is the resistance below 5.0 ohms?
All
Yes
→ Go To 7
No
→ Repair the open in the (K20) Gen Field Control circuit.
Perform POWERTRAIN VERIFICATION TEST VER - 3 - NGC.
7
NOTE: Before continuing, check the PCM connector terminals for corro-
sion, damage, or terminal push out. Repair as necessary.
If there are no possible causes remaining, view repair.
All
Repair
Replace and program the Powertrain Control Module in accor-
dance with the Service Information.
Perform POWERTRAIN VERIFICATION TEST VER - 3 - NGC.
428
DRIVEABILITY - NGC
P0622-GENERATOR FIELD CONTROL CIRCUIT —
Continued