B1492
B1459-TELEMATICS MIRROR CONTROL CIRCUIT LOWB1492-General Microphone Performance:
WHEN MONITORED
With the ignition on.
SET CONDITION
The Hands Free Module detects a fault in any of the microphone circuits.
POSSIBLE CAUSES
- (X712) MICROPHONE 1 IN (+) CIRCUIT OPEN
- (X722) Microphone 2 In (+) Circuit Open
- (X792) Microphone In (-) Circuit Open
- (X712) (X722) (X792) Microphone Circuits Shorted To Ground
- (X712) (X722) (X792) Microphone Circuits Shorted To Voltage
- (X712) (X722) (X792) Microphone Circuits Shorted Together
- Inside Rearview Mirror
- Hands Free Module
DIAGNOSTIC TEST
1. CHECK FOR ACTIVE DTC
With the scan tool, read the active DTC's.
Cycle the ignition switch from off to on at least 5 times, leaving the ignition on for a minimum of 90 seconds per cycle.
Attempt to make a phone call with the system.
With the scan tool, read the active DTC's.
Q: Does the scan tool display this DTC as active?
YES: Go To 2
NO: If the DTC is stored, check for an intermittent condition. Visually inspect the related wiring harness connectors. Look for broken, bent, pushed out, or corroded terminals.
2. (X712) MICROPHONE 1 IN (+) CIRCUIT OPEN
Turn the ignition off.
Disconnect the Hands Free Module harness connector.
Disconnect the Inside Rearview Mirror C2 harness connector.
Measure the resistance of the (X712) Microphone 1 IN (+) circuit between the HFM connector and the inside rearview mirror connector.
Q: Is the resistance below 5.0 ohms?
YES: Go To 3
NO: Repair the (X712) Microphone 1 IN (+) circuit for an open. Perform BODY VERIFICATION TEST - VER 1. Body Verification Test
3. (X722) MICROPHONE 2 IN (+) CIRCUIT OPEN
Measure the resistance of the (X722) Microphone 2 IN (+) circuit between the HFM connector and the inside rearview mirror connector.
Q: Is the resistance below 5.0 ohms?
YES: Go To 4
NO: Repair the (X722) Microphone 2 IN (+) circuit for an open. Perform BODY VERIFICATION TEST - VER 1. Body Verification Test
4. (X792) MICROPHONE IN (-) CIRCUIT OPEN
Measure the resistance of the (X792) Microphone IN (-) circuit between the HFM connector and the inside rearview mirror connector.
Q: Is the resistance below 5.0 ohms?
YES: Go To 5
NO: Repair the (X792) Microphone IN (-) circuit for an open. Perform BODY VERIFICATION TEST - VER 1. Body Verification Test
5. (X712) (X722) (X792) MICROPHONE CIRCUITS SHORTED TO GROUND
Measure the resistance between ground and each (X712) (X722) (X792) Microphone circuit.
Q: Is the resistance below 100.0 ohms?
YES: Repair the Microphone circuit that measured below 100.0 ohms for short to ground. Perform BODY VERIFICATION TEST - VER 1.
NO: Go To 6
6. (X712) (X722) (X792) MICROPHONE CIRCUITS SHORTED TO VOLTAGE
Turn the ignition on.
Measure the voltage of each (X712) (X722) (X792) Microphone circuit.
Q: Is the voltage above 1.0 volt?
YES: Repair the Microphone circuit that measured above 1.0 volt for short to voltage. Perform BODY VERIFICATION TEST - VER 1.
NO: Go To 7
7. (X712) (X722) (X792) MICROPHONE CIRCUITS SHORTED TOGETHER
Turn the ignition off.
Measure the resistance between each (X712) (X722) (X792) Microphone circuit.
Q: Is the resistance below 100.0 ohms?
YES: Repair the Microphone circuit that measured below 100.0 ohms for a short together.
NO: Go To 6
8. INSIDE REARVIEW MIRROR
Replace the Inside Rearview Mirror.
Cycle the ignition switch from off to on at least 5 times, leaving the ignition on for a minimum of 90 seconds per cycle.
Attempt to make a phone call with the system.
With the scan tool, read the active DTC's.
Q: Does the scan tool display this DTC as active?
YES: Inspect the wiring and connectors for damage or shorted circuits. If ok, replace and program the Hands Free Module. Perform BODY VERIFICATION TEST - VER 1.
NO: Repair is complete. Perform BODY VERIFICATION TEST - VER 1. Body Verification Test