Circuit/System Testing

WARNING: This page is about a different car, the 2021 GMC Sierra 3500 HD and 2021 GMC Sierra 2500 HD. However, it is still accessible from the selected car via links, so may be relevant.

NOTE:

It may take up to 2 min for all vehicle systems to power down before an accurate ground or low reference circuit continuity test can be performed.

Ignition/Vehicle & All vehicle systems - Off
Disconnect the electrical connector:S47D Seat Memory Switch - Driver
Test for less than 30 ohms between the test points:Low Reference circuit terminal 2 & Ground
- If 30 ohms or greater
1. Disconnect the electrical connector:X6 @ K40D Seat Memory Control Module - Driver
2. Test for less than 2 ohms between the test points:Low Reference circuit terminal 2 @ Component harness & Terminal 11 X6 @ Control module harness
  - If 2 ohms or greater - Repair the open/high resistance in the circuit.
  - If less than 2 ohms - Replace the component:K40D Seat Memory Control Module - Driver
- Go to next step: If less than 30 ohms
Ignition - On / Vehicle - In Service Mode
Operate the component:S64D Seat Adjuster Switch - Driver - Pressed
Test for greater than 9 V between the test points:
- Signal circuit terminal 3 @ Component harness & Ground
- Signal circuit terminal 4 @ Component harness & Ground
- If less than 9 V
1. Ignition/Vehicle - Off
2. Disconnect the electrical connector:X6 @ K40D Seat Memory Control Module - Driver
3. Test for infinite resistance between the test points:
  - Signal circuit terminal 3 @ Component harness & Ground
  - Signal circuit terminal 4 @ Component harness & Ground
  - If less than infinite resistance - Repair the short to ground on the circuit.
  - Go to next step: If less than infinite resistance
4. Test for less than 2 ohms between the test points:
  - Signal circuit terminal 3 @ Component harness & Terminal 12 X6 @ Control module harness
  - Signal circuit terminal 4 @ Component harness & Terminal 15 X6 @ Control module harness
  - If 2 ohms or greater - Repair the open/high resistance in the circuit.
  - If less than 2 ohms - Replace the component:K40D Seat Memory Control Module - Driver
- Go to next step: If 9 V or greater
Ignition/Vehicle - Off
Disconnect the electrical connector:X6 @ K40D Seat Memory Control Module - Driver
Ignition - On / Vehicle - In Service Mode
Test for less than 1 V between the test points:
- Terminal 3 @ Component harness & Ground
- Terminal 4 @ Component harness & Ground
- If 1 V or greater
  Repair the short to voltage on the circuit.
- Go to next step: If less than 1 V
Test or replace the component:S47D Seat Memory Switch - Driver