VOICE RECOGNITION/PHONE SWITCH CIRCUIT SHORT TO VOLTAGE
For a complete wiring diagram Refer to Section 8W.
- When Monitored:
With the ignition on.
- Set Condition:
The Hands Free Module detects voltage above 4.7 volts on the (X730) Voice Recognition/Phone Switch Signal circuit.
| Possible Causes |
| (X730) VOICE RECOGNITION/PHONE SWITCH SIGNAL CIRCUIT SHORT TO VOLTAGE |
| (X730) VOICE RECOGNITION/PHONE
SWITCH SIGNAL CIRCUIT OPEN |
| (X835) SENSOR GROUND CIRCUIT OPEN |
| AUTOMATIC DAY/NIGHT
MIRROR |
| HANDS FREE MODULE |
Diagnostic Test
1. CHECK FOR ACTIVE DTCTurn the ignition on.
With the scan tool, erase the HFM DTCs.
Attempt to make a phone call using the system.
With the scan tool, read the HFM DTCs.
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 Automatic Day/Night Mirror C2 harness connector.
Turn the ignition on.
Measure the voltage of the (X730) Voice Recognition/Phone Switch Signal circuit.
Is the voltage above 5.3 volts?
Yes
- Repair the (X730) Voice Recognition/Phone Switch Signal circuit for a short to voltage.
- Perform BODY VERIFICATION TEST – VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE).
No
- Go To 3
3. AUTOMATIC DAY/NIGHT MIRROR
Turn the ignition off.
Connect a jumper wire between (X730) Voice Recognition/Phone Switch Signal circuit and the (X835) Sensor Ground circuit.
Turn the ignition on.
With the scan tool, monitor the VR Phone Switch Voltage.
Is the voltage approximately 0 volts?
Yes
- Replace the Automatic Day/Night Mirror in accordance with the service information.
- Perform BODY VERIFICATION TEST – VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE).
No
- Go To 4
4. (X730) VOICE RECOGNITION/PHONE SWITCH SIGNAL CIRCUIT OPEN
Turn the ignition off.
Disconnect the Hands Free Module C1 harness connector.
Measure the resistance of the (X730) Voice Recognition/Phone Switch Signal circuit between the HFM connector and the Automatic Day/Night Mirror connector.
Is the resistance below 5.0 ohms?
Yes
- Go To 5
No
- Repair the (X730) Voice Recognition/Phone Switch Signal circuit for an open.
- Perform BODY VERIFICATION TEST – VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE).
5. (X835) SENSOR GROUND CIRCUIT OPEN
Measure the resistance of the (X835) Sensor Ground circuit between the HFM connector and the Automatic Day/Night Mirror connector.
Is the resistance below 5.0 ohms?
Yes
- 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. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE).
No
- Repair the (X835) Sensor Ground circuit for an open.
- Perform BODY VERIFICATION TEST – VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE).