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.
2016 Cadillac CTS Base, AWDFACTORY OEM SERVICE PROCEDURE
Circuit/System Testing
NOTE:
Use the schematics and connector end views to identify the device's ground, B+ and serial data circuit terminals.
- Ignition OFF, all access doors closed, all vehicle systems OFF and all keys at least 3 m (9.8 ft) away from vehicle. Disconnect all the harness connectors at the A10 Inside Rearview Mirror. It may take up to 2 minutes for all vehicle systems to power down.
- Test for less than 10 Ω between each ground circuit terminal and ground.
- If 10 Ω or greater
- Ignition OFF.
- Test for less than 2 Ω in the ground circuit end to end.
- If 2 Ω or greater, repair the open/high resistance in the circuit.
- If less than 2 Ω, repair the open/high resistance in the ground connection.
- If less than 10 Ω
- Ignition ON.
- Verify a test lamp illuminates between each B+ circuit terminal and ground.
- If the test lamp does not illuminate and the circuit fuse is good
- Ignition OFF.
- 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
- Ignition OFF.
- 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, replace the A10 Inside Rearview Mirror.
- If the test lamp illuminates
- Ignition OFF, all access doors closed, all vehicle systems OFF and all keys at least 3 m (9.8 ft) away from vehicle. Disconnect the harness connectors at the device setting the DTC. It may take up to 2 minutes for all vehicle systems to power down.
- Test for less than 2 Ω in each of the serial data circuits end to end between the A10 Inside Rearview Mirror and the device setting the DTC.
- If 2 Ω or greater
Repair the open/high resistance in the serial data circuit between the A10 Inside Rearview Mirror and the device setting the DTC or a serial data splice pack.
- If less than 2 Ω
- If 2 Ω or greater
- Replace the A10 Inside Rearview Mirror.
Factory Service Tools
Use the Manual With the Right Hardware
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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.