Buick Regal: DTC B1446 or B1447 (IOB/IO5/IO6)
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 for an overview of each
diagnostic category.
DTC Descriptors
DTC B1446
Replace Backup Power Source Below Minimum Threshold
DTC B1447
Backup Power Source Open Circuit
For symptom byte information refer to Symptom Byte List
Diagnostic Fault Information
Circuit/System Description
The backup power source provides voltage to the telematics communication
interface control module, to
be able to successfully place a call in the event of a main battery disconnect
during a collision event.
Conditions for Running the DTC
B1446 03
- Ignition On/Vehicle in Service Mode.
- System voltage is between 9.5 and 15.5 V.
- DTC B1447 is not set.
B1447 04
- Ignition On/Vehicle in Service Mode.
- System voltage is between 9.5 and 15.5 V.
- The above conditions are present for greater than 10 s.
Conditions for Setting the DTC
B1446 03
The telematics communication interface control module detects that the backup
power source voltage
has dropped below the minimum threshold value.
B1447 04
The telematics communication interface control module detects no voltage from
the backup power
source.
Action Taken When the DTC Sets
B1446 03
The OnStar status LED turns red.
B1447 04
- The OnStar status LED turns red.
- The telematics communication interface control module will be unable to
place a call in the event
of a main battery disconnect during a collision event.
Conditions for Clearing the DTC
- A current DTC B1446 will clear when the telematics communication
interface control module
detects the voltage of the backup power source is above the minimum
threshold value.
- A current DTC B1447 will clear when the telematics communication
interface control module
detects voltage from the backup power source.
- A history DTC clears after 50 malfunction-free ignition cycles.
Diagnostic Aids
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 Testing for Intermittent Conditions and Poor Connections
- Refer to Circuit Testing
- Refer to Wiring Repairs
- Refer to Connector Repairs
Circuit/System Testing
1. Ignition OFF/Vehicle OFF and all vehicle systems OFF, disconnect the X1
harness connector at
the K73 Telematics Communication Interface Control Module. It may take up to 2
minutes for all
vehicle systems to power down.
2. Test for greater than 12.3 V between the B+ circuit terminal 14 and the low
reference circuit
terminal 13.
- Disconnect the C3 Telematics Communication Interface Control Module
Battery.
- Test for infinite resistance between the circuits listed below and
ground.
- B+ circuit terminal 14
- Low reference circuit terminal 13.
- 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 circuits end to end.
- If 2 Ω or greater, repair the open/high resistance in the circuit.
- If less than 2 Ω, replace the C3 Telematics Communication Interface
Control Module
Battery.
- Go to next step: If greater than 12.3 V
3. Replace the K73 Telematics Communication Interface Control Module.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair.
- Refer to Communication Interface Module Battery Replacement (IO5, IO6,
IOB) or
Communication Interface Module Battery Replacement (IOR, IOS, IOT)
- 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:
Power Outlets 12-Volt Direct
Current
The 12-volt power outlets can be
used to plug in electrical equipment,
such as a cell phone or MP3 player.
The vehicle may have accessory
power outlets:
Below the climate controls.
In the cargo area, if equipped.
Open the protective cover to use the
power ou
This section is only for people of
adult size.
There are special things to know
about seat belts and children, and
there are different rules for smaller
children and infants. If a child will be
riding in the vehicle. Follow those rules for
everyone's protection.
It is very important for all occupa