Service Information

Volt

DTC B2470

Diagnostic Instructions

•	Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

•	Review Strategy Based Diagnosis for an overview of the diagnostic approach.

•	Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptors

DTC B2470 01: Mobile Phone Aerial Circuit Short to Battery

DTC B2470 02: Mobile Phone Aerial Circuit Short to Ground

DTC B2470 04: Mobile Phone Aerial Circuit Open

Circuit/System Description

The mobile phone aerial is connected to the Mobile Telephone Control Module. This module supplies 5 V to the mobile phone aerial to power the internal amplifier.

Conditions for Running the DTC

•	The vehicle is ON.

•	System voltage is between 9.5-15.5 V.

•	The above conditions are present for greater than 1 s.

Conditions for Setting the DTC

The Mobile Telephone Control Module does not detect the presence of a mobile phone aerial.

Action Taken When the DTC Sets

Mobile telephone communication cannot be established.

Conditions for Clearing the DTC

•	The Mobile Telephone Control Module detects the presence of a mobile phone aerial.

•	A history DTC clears after 50 malfunction free ignition cycles.

Reference Information

Electrical Information Reference

•	Circuit Testing

•	Connector Repairs

•	Testing for Intermittent Conditions and Poor Connections

•	Wiring Repairs

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

Verify that the Mobile Phone Aerial assembly is not damaged.

⇒	If the antenna assembly is damaged, replace the T4F Mobile Phone Antenna or T4E Mobile Phone and Navigation Antenna.

Circuit/System Testing

Note: The vehicle may be equipped with sectioned coax. Test each section and replace only the faulty section, not the entire length of coax.

Vehicle OFF, disconnect the mobile coax cable connector at the T4F Mobile Phone Aerial or T4E Mobile Phone and Navigation Aerial.
Vehicle ON, Test for 5 V between the coax cable centre wire and the outer coax shield.

⇒	If less than the specified range, test the coax cable for an open/high resistance or a short to ground. If the coax cable tests normal, replace the K82 Mobile Telephone Control Module.

⇒	If greater than the specified range, test the coax cable for a short to voltage. If the coax cable tests normal, replace the K82 Mobile Telephone Control Module.

If all circuits test normal, replace the T4F Mobile Phone Antenna or T4E Mobile Phone and Navigation Antenna.

Component Testing

Caution: Refer to Test Probe Caution in the Preface section.

Note: Before testing the coax cable, check the cable exterior for being pinched, cut, damaged, or having loose connections at the components, which can cause reception issues.

To prevent false reading when testing the centre coax terminals, use care not to ground the test probe on the outer housing/shield.

Coax Cable Test

Vehicle OFF, disconnect the coax cable at both components.
Test for less than 5 Ω between both ends of the coax cables centre terminals.

⇒	If greater than the specified range, replace the failed coax cable.

Test for greater than infinite resistance between the coax cable centre wire and the outer coax shield.

⇒	If less than the specified range, replace the coax cable.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

•	Radio Aerial Base Replacement

•	Control Module References for telematics communication interface control module replacement, programming and setup