Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Circuit/System Testing
2019 Chevrolet Blazer Premier, FWDSECTION Circuit/System Testing
- Ignition/Vehicle & All vehicle systems - Off
- Disconnect the electrical connector: B24LF Mobile Telephone Microphone - Left Front
- Ignition - On/Vehicle - In Service Mode
- Test for 8.0 to 10.5 V between the test points: Signal circuit terminal B & Ground
- If less than 8.0 V
- Ignition/Vehicle & All vehicle systems - Off
- Disconnect the electrical connector: X1 @ K73 Telematics Communication Interface Control Module
- Test for infinite resistance between the test points: Signal circuit terminal B & Ground
- If less than infinite resistance - Repair the short to ground on the circuit.
- Go to next step: If infinite resistance
- Test for less than 2 ohms between the test points: Signal circuit terminal B & 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: K73 Telematics Communication Interface Control Module
- If greater than 10.5 V
- Ignition/Vehicle & All vehicle systems - Off
- Disconnect the electrical connector: X1 @ K73 Telematics Communication Interface Control Module
- Ignition - On/Vehicle - In Service Mode
- Test for less than 1 V between the test points: Signal circuit terminal B & Ground
- If 1 V or greater - Repair the short to voltage on the circuit.
- If less than 1 V - Replace the component: K73 Telematics Communication Interface Control Module
- Go to next step: If between 8.0 and 10.5 V
- Test for less than 1 V between the test points: Low Reference circuit terminal A & Ground
- If greater than 1 V
- Ignition/Vehicle & All vehicle systems - Off
- Disconnect the electrical connector: X1 @ K73 Telematics Communication Interface Control Module
- Ignition - On/Vehicle - In Service Mode
- Test for less than 1 V between the test points: Low Reference circuit terminal A & Ground
- If 1 V or greater - Repair the short to voltage on the circuit.
- If less than 1 V - Replace the component: K73 Telematics Communication Interface Control Module
- Go to next step: If less than 1 V
- Test for greater than 8 V between the test points: Signal circuit terminal B & Low Reference circuit terminal A
- If less than 8 V
- Ignition/Vehicle & All vehicle systems - Off
- Disconnect the electrical connector: X1 @ K73 Telematics Communication Interface Control Module
- Test for infinite resistance between the test points: Low Reference circuit terminal A & Ground
- If less than infinite resistance - Repair the short to ground on the circuit.
- Go to next step: If infinite resistance
- Test for less than 2 ohms between the test points: Low Reference circuit terminal A & 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: K73 Telematics Communication Interface Control Module
- Go to next step: If greater than 8 V
- Test or replace the component: B24LF Mobile Telephone Microphone - Left Front
RENDER: 1.0x
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.