Voice Recognition/Phone Switch Circuit Rationality

VOICE RECOGNITION/PHONE SWITCH CIRCUIT RATIONALITY





WHEN MONITORED
With the ignition on.

SET CONDITION
The Hands Free Module detects an invalid voltage signal on the (X730) Voice Recognition/Phone Switch Signal circuit.

POSSIBLE CAUSES
- 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.
While monitoring the VR Phone Switch voltage, momentarily connect a jumper wire between the (X730) Voice Recognition/Phone Switch Signal circuit and ground.

NOTE: The sensor voltage should switch from above 4.7 volts when the jumper is not connected to below 0.6 volts when the jumper is connected.

Q: Does the sensor voltage switch from above 4.7 volts to below 0.6 volt as described?

YES: Replace the Inside Rearview Mirror in accordance with the service information. 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.