Circuit/System Testing

WARNING: This page is about a different car, the 2022 Cadillac CT4. However, it is still accessible from the selected car via links, so may be relevant.

Refer to: SIR Service Precautions
Refer to: SIR Disabling and Enabling .
Inspect the terminals of the following components and connectors for damage or corrosion and repair or replace as necessary:
- B153D Front Seat Belt Buckle - Driver
- B153D Front Seat Belt Buckle - Driver & Harness Connector
- K36 Inflatable Restraint Sensing and Diagnostic Module
- K36 Inflatable Restraint Sensing and Diagnostic Module & Harness Connector

Ignition - On / Vehicle - In Service Mode
Disconnect the electrical connector: B153D Front Seat Belt Buckle - Driver
Test for less than 5 ohms between the test points: Low Reference terminal 1 & Ground
- If 5 ohms or greater
1. Before attempting these procedures, the SIR system must be disabled.
2. Disconnect the electrical connector: K36 Restraints Control Module
3. Test for less than 2 ohms between the test points: Low Reference circuit terminal 1 @ B153D Front Seat Belt Buckle - Driver & The other end of the circuit
  - If 2 ohms or greater - Repair the open/high resistance in the circuit.
  - If less than 2 ohms - Replace the component: K36 Restraints Control Module
- Go to next step: If less than 5 ohms
Ignition - On / Vehicle - In Service Mode
Verify the scan tool parameter: Driver Seat Belt Status = Buckled
- If not the specified state
1. Ignition/Vehicle - Off
2. Before attempting these procedures, the SIR system must be disabled.
3. Disconnect the electrical connector: K36 Restraints Control Module
4. Test for infinite resistance between the test points: Signal circuit terminal 2 @ Component harness & Ground
  - If less than infinite resistance - Repair the short to ground on the circuit.
  - If infinite resistance - Replace the component: K36 Restraints Control Module
- Go to next step: If the specified state
Connect a 3 A fused jumper wire between the test points: Signal circuit terminal 2 & Low Reference circuit terminal 1
Verify the scan tool parameter: Driver Seat Belt Status = Unbuckled
- If not the specified state
1. Ignition/Vehicle - Off & Remove - Jumper wire (s)
2. Before attempting these procedures, the SIR system must be disabled.
3. Disconnect the electrical connector: K36 Restraints Control Module
4. Ignition - On / Vehicle - In Service Mode
5. Test for less than 1 V between the test points: Signal circuit terminal 2 @ 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
6. Ignition/Vehicle - Off
7. Test for less than 2 ohms between the test points: Signal circuit terminal 2 @ Component harness & The other end of the circuit
  - If 2 ohms or greater - Repair the open/high resistance in the circuit.
  - If less than 2 ohms - Replace the component: K36 Restraints Control Module
- Go to next step: If the specified state
Test or replace the component: B153D Front Seat Belt Buckle - Driver