Voice Recognition/Phone Switch Circuit Shorted to Ground

VOICE RECOGNITION/PHONE SWITCH CIRCUIT SHORT TO GROUND






WHEN MONITORED
With the ignition on.

SET CONDITION
The Hands Free Module detects voltage below 0.6 volts on the (X730) Voice Recognition/Phone Switch Signal circuit.

POSSIBLE CAUSES
- (X730) Voice recognition/phone switch signal circuit short to (X835) sensor ground circuit
- (X730) Voice recognition/phone switch signal circuit short to ground
- Inside rearview mirror
- Hands free module

DIAGNOSTIC TEST

1. CHECK FOR ACTIVE DTC
Turn the ignition on.
With the DRB, erase the HFM DTCs.
Attempt to make a phone call using the system.
With the DRB, read the HFM DTCs.

Q: Did this DTC reset?

YES: Go To 2

NO: The condition that set this DTC is no longer present. Using the wiring diagram/schematic as a guide, inspect the wiring for chafed, pierced, pinched, and partially broken wires and the wiring harness connectors for broken, bent, pushed out, and corroded terminals.

2. CHECK THE VOLTAGE OF THE (X730) VOICE RECOGNITION/PHONE SWITCH SIGNAL




Turn the ignition off.
Disconnect the Inside Rearview Mirror C2 harness connector.
Turn the ignition on.
With the DRB, monitor the VR Phone Switch voltage.

Q: Is the voltage above 4.7 volts?

YES: Replace the Inside Rearview Mirror in accordance with the service information. Perform BODY VERIFICATION TEST - VER 1.

NO: Go To 3

3. (X730) VOICE/RECOGNITION/PHONE SWITCH SIGNAL CIRCUIT SHORTED TO THE (X835) SENSOR GROUND CIRCUIT




Turn the ignition off.
Disconnect the Hands Free Module harness connector.
Measure the resistance between the (X730) Voice Recognition/Phone Switch Signal circuit and the (X835) Sensor Ground circuit.

Q: Is the resistance below 100.0 ohms?

YES: Repair the (X730) Voice Recognition/Phone Switch Signal circuit for a short to the (X835) Sensor Ground circuit. Perform BODY VERIFICATION TEST - VER 1.

NO: Go To 4

4. (X730) VOICE/RECOGNITION/PHONE SWITCH SIGNAL CIRCUIT SHORTED TO GROUND




Measure the resistance between ground and the (X730) Voice Recognition/Phone Switch Signal circuit.

Q: Is the resistance below 100.0 ohms?

YES: Repair the (X730) Voice Recognition/Phone Switch Signal circuit for a short to ground. Perform BODY VERIFICATION TEST - VER 1.

NO: Inspect the wiring and connectors for damage or shorted circuits. If Ok, replace and program the Hands Free Module in accordance with the service information. Perform BODY VERIFICATION TEST - VER 1.