Buick Regal: DTC B2455 (IO5/IO6/IOB)
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.
- Refer to Diagnostic Procedure Instructions provide an overview of each
diagnostic category.
DTC Descriptors
DTC B2455 02
Cellular Phone Microphone Circuit Short to Ground
DTC B2455 04
Cellular Phone Microphone Circuit Open
Diagnostic Fault Information
Circuit/System Description
The telematics communication interface control module provides the cellular
phone microphone with a
supplied voltage on the cellular phone microphone high signal circuit. When the
microphone is in use,
voice data from the user is sent back to the telematics communication interface
control module on the
microphone low signal circuit.
Conditions for Running the DTC
- The Vehicle must be ON or in Service Mode.
- The system voltage is at least 9.5 V and no more than 15.5 V.
- All the above conditions are present for greater than 10 s.
Conditions for Setting the DTC
B2455 02
The telematics communication interface control module detects a short to
ground in the cellular phone
microphone signal circuit for 10 s or greater.
B2455 04
The following conditions will set this DTC:
- The telematics communication interface control module detects an
open/high resistance in the
cellular phone microphone signal circuit for 10 s or greater.
- The telematics communication interface control module detects an
open/high resistance in the low
signal circuit for 10 s or greater.
Action Taken When the DTC Sets
- The OnStar status LED turns red.
- The telematics communication interface control module will not receive a
signal from the cellular
phone microphone.
- Calls can be placed but the caller cannot be heard.
Conditions for Clearing the DTC
- The condition responsible for setting the DTC no longer exists.
- A history DTC will clear once 50 consecutive malfunction-free ignition
cycles have occurred.
Reference Information
Schematic Reference
OnStar/Telematics Wiring Schematics
Connector End View Reference
Component Connector End View Index
Description and Operation
OnStar Description and Operation (UE1 with IOB/IO6) , OnStar Description
and Operation (UI3)
, or OnStar Description and Operation (UE1 without IOB/IO6).
Electrical Information Reference
- Refer to Circuit Testing
- Refer to Connector Repairs
- Refer to Testing for Intermittent Conditions and Poor Connections
- Refer to Wiring Repairs
Scan Tool Reference
Control Module References for scan tool information.
Circuit/System Testing
1. Ignition OFF/Vehicle OFF, disconnect the harness connector at the B24
cellular phone
microphone, Ignition ON/Vehicle in Service Mode.
2. Test for 8.0-10.5 V between the signal circuit terminal B and ground.
- Ignition OFF/Vehicle OFF, disconnect the X2 harness connector at the K73
telematics
communication interface control module.
- Test for infinite resistance between the signal circuit and ground.
- If less than infinite resistance, repair the short to ground in the
circuit.
- Go to next step: If infinite resistance
- Test for less than 2 Ω in the signal circuit end to end.
- If 2 Ω or greater, repair the open/high resistance in the circuit.
- If less than 2 Ω, replace the vehicle K73 Telematics Communication
Interface Control
Module.
- Ignition OFF/Vehicle OFF, disconnect the X2 harness connector at the K73
telematics
communication interface control module, Ignition ON/Vehicle in Service Mode.
- Test for less than 1 V between the signal circuit and ground.
- If 1 V or greater, repair the short to voltage on the circuit.
- Go to next step: If less than 1 V, replace the K73 Telematics
Communication Interface
Control Module.
- Go to next step: If between 9.5-10.5 V
3. Test for less than 1 V between the signal circuit terminal A and ground.
- Ignition OFF/Vehicle OFF, disconnect the X2 harness connector at the K73
telematics
communication interface control module, Ignition ON/Vehicle in Service Mode.
- Test for less than 1 V between the signal circuit and ground.
- If 1 V or greater, repair the short to voltage in the circuit.
- If less than 1 V, repair the K73 Telematics Communication Interface
Control Module.
- Go to next step: If less than 1 V
4. Test for greater than 8 V between the signal circuit terminal B and the
signal circuit terminal A.
- Ignition OFF/Vehicle OFF, disconnect the connector X2 at the K73
telematics
communication interface control module.
- Test for infinite resistance between the low signal circuit and ground.
- If less than infinite resistance, repair the short to ground in the
circuit.
- Go to next step: If infinite resistance
- Test for less than 2 Ω in the signal circuit end to end.
- If 2 Ω or greater, repair the open/high resistance in the circuit.
- If less than 2 Ω, replace the vehicle K73 Telematics Communication
Interface Control
Module.
- Go to next step: If greater than 8 V
5. Test or replace the B24 Cellular Phone Microphone.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair.
- Refer to Mobile Telephone Microphone Replacement
- Refer to Control Module References for telematics communication
interface control module
replacement, programming and setup.
READ NEXT:
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.
Refe
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.
Refe
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.
Refe
SEE MORE:
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
D
Removal Procedure
1. Control Valve Body - Remove - Refer to Control Valve Body Replacement.
2.
Input Speed Sensor Bolt (1) - Remove.
3. Input Speed Sensor (2) - Remove.
Installation Procedure
1.
Input Speed Sensor (2) - Install.
CAUTION: Refer to Fastener Caution.
2. Input Speed Sensor Bolt (1) -