Buick Regal: DTC B0193
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 B0193 01
Front Blower Motor Speed Circuit Short to Battery
DTC B0193 06
Front Blower Motor Speed Circuit Low Voltage/Open
Diagnostic Fault Information
Circuit/System Description
The blower motor control module is an interface between the HVAC control
module and the blower
motor. The blower motor control module has 5 circuits: a B+ input, ground, a
control circuit from the
HVAC control module, a B+ output to the blower motor, and a low side pulse width
modulation (PWM)
output. The HVAC control module provides a low side (PWM) signal to the blower
motor control
module in order to request the blower motor speed. The blower motor control
module grounds the
blower motor using a low side PWM signal in order to vary the blower motor
speed.
Conditions for Running the DTC
- Ignition ON.
- The HVAC control module is ON.
Conditions for Setting the DTC
B0193 01
The voltage at the HVAC control module output to the blower motor control
module is always high.
B0193 06
The voltage at the HVAC control module output to the blower motor control
module is always low or
fluctuating.
Action Taken When the DTC Sets
The blower motor is inoperative.
Conditions for Clearing the DTC
The condition for setting the DTC is no longer present.
Diagnostic Aids
Inspect the motor shaft for rust or other foreign material which may prohibit
proper motor operation.
If the motor operates properly please reinstall it and check for Preliminary
Information or Technical
Service Bulletins.
Reference Information
Schematic Reference
HVAC Wiring Schematics
Connector End View Reference
Component Connector End View Index
Description and Operation
Automatic HVAC Description and Operation
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 Testing
1. Ignition OFF and all vehicle systems OFF, disconnect the X1 harness
connector at the K8 Blower
Motor Control Module. It may take up to 10 min for all vehicle systems to power
down.
2. Test for less than 10 Ω between the ground circuit terminal 5 and ground.
- Ignition OFF.
- Test for less than 2 Ω in the ground circuit end to end.
- If 2 Ω or greater, repair the open/high resistance in the circuit.
- If less than 2 Ω, repair the open/high resistance in the ground
connection.
- Go to next step: If less than 10 Ω
3. Verify a test lamp illuminates between the B+ circuit terminal 6 and
ground.
- If the test lamp does not illuminate and the circuit fuse is good
- Ignition OFF, remove the test lamp.
- Test for less than 2 Ω in the B+ circuit end to end.
- If 2 Ω or greater, repair the open/high resistance in the circuit.
- If less than 2 Ω, verify the fuse is not open and there is voltage
at the fuse.
- If the test lamp does not illuminate and the circuit fuse is open
- Ignition OFF, remove the test lamp.
- Test for infinite resistance between the B+ circuit terminal 6 and
ground.
- If less than infinite resistance, repair the short to ground on the
circuit.
- Go to next step: If infinite resistance
- Disconnect the X2 harness connector at the K8 Blower Motor Control
Module and
disconnect the harness connector at the M8 Blower Motor.
- Test for infinite resistance between the M8 Blower Motor B+ circuit
terminal B and ground.
- If less than infinite resistance, repair the short to ground on the
circuit.
- If infinite resistance, test or replace the M8 Blower Motor.
- Go to next step: If the test lamp illuminates
4. Ignition ON. Test for less than 1 V between the control circuit terminal 3
and ground.
- Ignition OFF, disconnect the X2 harness connector at the K33 HVAC
Control Module.
Ignition ON.
- Test for less than 1 V between the control circuit and ground.
- If 1 V or greater, repair the short to voltage on the circuit.
- If less than 1 V, replace the K33 HVAC Control Module
- Go to next step: If less than 1 V
5. Ignition OFF. It may take up to 10 min for all vehicle systems to power
down.
6. Test for infinite resistance between the control circuit terminal 3 and
ground.
- If less than infinite resistance
- Disconnect the X2 harness connector at the K33 HVAC Control Module.
- Test for infinite resistance between the control circuit and ground.
- If less than infinite resistance, repair the short to ground on the
circuit.
- If infinite resistance, replace the K33 HVAC Control Module
- Go to next step: If infinite resistance
NOTE: Verify the ignition is OFF before connecting the blower motor
control module or incorrect test results may occur.
7. Ignition OFF, connect the X1 harness connector at the K8 Blower Motor
Control Module. Ignition
ON.
8. While backprobing terminal 3 at the K8 Blower Motor Control Module, test for
greater than 1 V
between the control circuit and ground.
Replace the K8 Blower Motor Control Module.
- Go to next step: If 1 V or greater
9. Verify the voltage decreases and increases while using the controls to
change the blower speed
selection.
- If the voltage does not decrease and increase as the blower speed
selection is changed
- Ignition OFF, disconnect the X2 harness connector at the K33 HVAC
Control Module.
- Test for less than 2 Ω in the control circuit end to end.
- If 2 Ω or greater, repair the open/high resistance in the circuit.
- If less than 2 Ω, replace the K33 HVAC Control Module.
- Go to next step: If the voltage decreases and increases as the blower
speed selection is
changed
10. Ignition OFF, disconnect the harness connector at the M8 Blower Motor,
ignition ON and blower
ON.
11. Verify a test lamp illuminates between the B+ circuit terminal B and ground.
- If the test lamp does not illuminate
- Ignition OFF, disconnect the X2 harness connector at the K8 Blower Motor
Control
Module.
- Test for less than 2 Ω in the control circuit end to end.
- If 2 Ω or greater, repair the open/high resistance in the circuit.
- If less than 2 Ω replace the K8 Blower Motor Control Module.
- Go to next step: If the test lamp illuminates
12. Connect a test lamp between control circuit terminal A and B+ circuit
terminal B.
13. Verify the test lamp becomes progressively brighter as the blower speed is
increased and
progressively dimmer as the blower speed is decreased.
- If the test lamp does not illuminate
- Ignition OFF, disconnect the X2 harness connector at the K8 Blower Motor
Control
Module, ignition ON.
- Test for less than 1 V between the control circuit terminal 1 and
ground.
- If 1 V or greater, repair the short to voltage on the circuit.
- Go to next step: If less than 1 V
- Test for less than 2 Ω in the control circuit end to end.
- If 2 Ω or greater, repair the open/high resistance in the circuit.
- If less than 2 Ω replace the K8 Blower Motor Control Module.
- If the test lamp illuminates, but does not change in brightness
- Ignition OFF, disconnect the X2 harness connector at the K8 Blower Motor
Control
Module.
- Test for infinite resistance between the control circuit and ground.
- If less than infinite resistance, repair the short to ground on the
circuit.
- If infinite resistance, replace the K8 Blower Motor Control Module.
- Go to next step: If the test lamp changes in brightness as the blower
speed is changed
14. Test or replace the M8 Blower Motor.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair.
- HVAC Component Replacement Reference
- Control Module References for 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.
Diag
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.
Diag
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.
Diag
SEE MORE:
Touch and the following may
display:
Vehicle Locator Lights
Exit Lighting
Left or Right Hand Traffic
Adaptive Forward Lighting
Vehicle Locator Lights
This feature will flash the exterior
lamps and allows some of the
exterior lamps and most of the
interior lamps to turn on briefly
when on the
To ensure proper engine
performance and long life, careful
attention must be paid to engine oil.
Following these simple, but
important steps will help protect
your investment:
Use engine oil approved to the
proper specification and of the
proper viscosity grade. See
"Selecting the Right Engine