vauxhall Workshop Repair Guides

Vauxhall Workshop Service and Repair Manuals

ABOUT US
No Global Positioning System (GPS) Reception > < Fastener Tightening Specifications

Astra J

DTC B125A

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 B125A 02: Antenna Signal Circuit Short to Ground
DTC B125A 04: Antenna Signal Circuit Open

Diagnostic Fault Information



Circuit
Short to Ground
Open/High Resistance
Short to Voltage
Signal Performance

Radio Antenna Signal
B125A 02
B125A 04
1
-

Ground
-
1
-
-

1. May exhibit possible AM/FM interference.
 

Circuit/System Description

The multi-band antenna is located on the roof of the vehicle. The radio antenna is enabled when the radio is turned on. The radio provides battery voltage to the antenna using the center conductor of the antenna coaxial cable. When a 12 V signal is seen on the center conductor of the antenna coax, both AM and FM signals are amplified.

Conditions for Running the DTC

•  Ignition ON.
•  Battery voltage must be between 9-16 V.

Conditions for Setting the DTC

B125A 02

The radio detects a short to ground in the antenna signal circuit center conductor.

B125A 04

The radio detects an open in the antenna signal circuit center conductor.

Action Taken When the DTC Sets

Radio reception may be poor or not available.

Conditions for Clearing the DTC

•  The condition responsible for setting the DTC no longer exists.
•  A history DTC will clears after 50 consecutive malfunction-free ignition cycles have occurred.

Reference Information


Schematic Reference

Radio/Navigation System Schematics


Connector End View Reference

Component Connector End Views


Description and Operation

Radio/Audio System Description and Operation


Electrical Information Reference


Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

Ignition ON, A11 Radio ON, tune to a strong AM or FM station. Verify that the AM or FM reception is clear.

Circuit/System Testing

1. Ignition OFF, disconnect the radio antenna coax from the A11 Radio and from the radio antenna.
2. Test for infinite resistance between the antenna coax center terminal and ground.
⇒ If less than the specified value, replace the antenna coax.
3. Test for less than 5 Ω on the antenna coax center circuit from end to end.
⇒ If greater than the specified range, replace the antenna coax.
4. Ignition ON, test for less than 1 V between the antenna coax center terminal and ground.
⇒ If greater than the specified range, replace the antenna coax.
5. Test for infinite resistance between the coax center terminal and the outer shield.
⇒ If less than the specified value, replace the antenna coax.
6. Connect the antenna coax to the A11 Radio. Test for 12-15 V between the antenna coax center terminal and ground at the radio antenna connector.
⇒ If not within the specified range, replace the A11 Radio.
7. If all circuits test normal, replace the radio antenna.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

•  Control Module References for radio replacement, setup, and programming

No Global Positioning System (GPS) Reception > < Fastener Tightening Specifications