Circuit/System Testing

WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2020 Buick Regal TourX, 2020 Buick Regal, 2019 Buick Regal TourX, 2019 Buick Regal, and 2018 Buick Regal TourX. However, it is still accessible from the selected car via links, so may be relevant.

NOTE:

You must perform the Circuit/System Verification before proceeding with Circuit/System Testing.

Verify a test lamp illuminates between the G13 Generator B+ circuit terminal 1 X2 or 2 X2 and ground.
- If the test lamp does not illuminate and the circuit fuse is good
1. Remove the test lamp and disconnect the B+ cable at the G13 Generator.
2. Test for less than 2 Ω in the B+ circuit end to end.
  - If 2 Ω or greater, repair the open/high resistance in the circuit.
  - If less than 2 Ω, verify the fuse is not open and there is voltage at the fuse.
- If the test lamp does not illuminate and the circuit fuse is open
1. Remove the test lamp, disconnect the battery negative cable, and disconnect the G13 Generator B+ cable.
2. Test for infinite resistance between the B+ circuit and ground.
  - If less than infinite resistance, repair the short to ground on the circuit.
  - If infinite resistance, test or replace the G13 Generator.
- Go to next step: If the test lamp illuminates
Disconnect the X1 harness connector at the G13 Generator, engine running.
Test for 13.4 V to 14 V between the engine block and B+ circuit at G13 Generator.
- If not between 13.4 and 14 V, Test or replace the G13 Generator.
- Go to next step: If between 13.4 and 14 V
Verify the scan tool Engine Control Module Generator F - Terminal Signal parameter is less than 5%.
- If 5% or greater
1. Ignition OFF, disconnect the X2 harness connector at the K20 Engine Control Module, ignition ON.
2. Test for less than 1 V between the G13 Generator signal circuit terminal 2 X1 and ground.
  - If 1 V or greater, repair the short to voltage on the circuit.
  - If less than 1 V, replace the K20 Engine Control Module.
- Go to next step: If less than 5%
Install a 3 A fused jumper wire between the signal circuit terminal 2 X1 and B+, engine running.
Verify the scan tool Engine Control Module Generator F - Terminal Signal parameter is greater than 95%.
- If 95% or less
1. Ignition OFF, remove the jumper wire, disconnect the harness connector at the K20 Engine Control Module.
2. Test for infinite resistance between the signal circuit and ground.
  - If less than infinite resistance, repair the short to ground on the circuit.
  - Go to next step: If infinite resistance
3. Test for less than 2 Ω in the signal circuit end to end.
  - If 2 Ω or greater, repair the open/high resistance in the circuit
  - If less than 2 Ω, replace the K20 Engine Control Module.
- Go to next step: If greater than 95%
Remove jumper wire. X1 disconnected at G13 Generator, engine running.
Test for 1 V or greater between the control circuit terminal 1 X1 and ground.
- If less than 1 V
1. Ignition OFF, disconnect the harness connectors at the K20 Engine Control Module.
2. Test for infinite resistance between the control circuit and ground.
  - If less than infinite resistance, repair the short to ground on the circuit.
  - Go to next step: If infinite resistance
3. Test for less than 2 Ω in the control circuit end to end.
  - If greater than 2 Ω, repair the open/high resistance in the circuit.
  - If less than 2 Ω, replace the K20 Engine Control Module.
- Go to next step: If 1 V or greater
Ignition OFF, disconnect the harness connectors at the K20 Engine Control Module, Ignition ON
Test for less than 1 V between the G13 Generator control circuit terminal 1 X1 and ground.
- If greater than 1 V
  Repair the short to voltage on the circuit.
- Go to next step: If 1 V or less
Test or replace the G13 Generator.