DTC B1114 (UE1)
Cellular, Entertainment, and Navigation | Diagnostic Information and Procedures | Document ID: 5158780 Diagnostic Instructions Perform the Diagnostic System Check prior to using this diagnostic procedure: Diagnostic System Check - Vehicle Review the description of Strategy Based Diagnosis: Strategy Based Diagnosis An overview of each diagnostic category can be found here: Diagnostic Procedure Instructions DTC Descriptor DTC B1114 Cellular Telephone Microphone Signal Symptom Byte Information: Symptom Byte List Diagnostic Fault Information
| Circuit | Circuit Function | Short to Ground | Open/High Resistance | Short to Voltage |
|---|---|---|---|---|
| 655 | Signal | B1114 11 | B1114 13 | — |
| 654 | Low Reference | — | B1114 13 | — |
Circuit/System Description The K73 Telematics Control Module provides the B24LF Mobile Telephone Microphone — Left Front or the B24 Mobile Telephone Microphone (depending on radio RPO) with a supplied voltage on the cellular phone microphone high signal circuit 655. When the microphone is in use, voice data from the user is sent back through the K73 Telematics Control Module to the radio on the cellular microphone low reference circuit 654. Conditions for Running the DTC Vehicle in Service Mode. The system voltage is between 9 V and 16 V. All the above conditions are present for greater than 5 s. Conditions for Setting the DTC B1114 11 Circuit 655 is shorted to ground for 250 ms or greater. B1114 13 The following conditions will set this DTC: Circuit 655 has open/high resistance for 750 ms or greater. Circuit 654 has open/high resistance for 750 ms or greater. Action Taken When the DTC Sets The K73 Telematics 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 conditions for setting the DTC no longer exist. A history DTC will clear after 100 consecutive malfunction-free ignition cycles. Reference Information Schematic Reference OnStar/Telematics Schematics Connector End View Reference Master Electrical Component List Electrical Information Reference Circuit Testing Connector Repairs Testing for Intermittent Conditions and Poor Connections Wiring Repairs Scan Tool Reference Control Module References Circuit/System Testing
- Ignition/vehicle OFF, disconnect the harness connector at the appropriate B24 Mobile Telephone Microphone, ignition ON/vehicle in service mode.
- Test for 8-11 V between the signal circuit terminal 2 and ground. ⇒ If less than 8 V 2.1. Test circuit 655 for a short to ground. ⇒ If a short to ground is found, repair the fault on the circuit. ⇓ If a short to ground is not found. 2.2. Test circuit 655 for an open/high resistance. ⇒ If an open/high resistance is found, repair the fault on the circuit. ⇓ If an open/high resistance is not found. 2.3. Replace the K73 Telematics Control Module. ⇒ If greater than 11 V 2.1. Test circuit 655 for a short to voltage. ⇒ If a short to voltage is found, repair the fault on the circuit. ⇓ If a short to voltage is not found. 2.2. Replace the K73 Telematics Control Module. ⇓ If between 8-11 V
- Test for less than 1 V between the low reference circuit terminal 1 and ground. ⇒ If greater than 1 V 3.1. Test circuit 654 for a short to voltage. ⇒ If a short to voltage is found, repair the fault on the circuit. ⇓ If a short to voltage is not found. 3.2. Replace the K73 Telematics Control Module. ⇓ If less than 1 V
- Test for greater than 8 V between the signal circuit terminal 2 and the low reference circuit terminal 1. ⇒ If less than 8 V 4.1. Test circuit 654 for an open/high resistance in the circuit. ⇒ If an open/high resistance is found, repair the fault on the circuit. ⇓ If an open/high resistance is not found. 4.2. Replace the K73 Telematics Control Module. ⇓ If greater than 8 V
- Replace the appropriate B24 Mobile Telephone Microphone. Repair Instructions Perform the Diagnostic Repair Verification after completing the repair: Diagnostic Repair Verification Mobile Telephone Microphone Replacement For control module replacement, programming, and setup refer to: Control Module References