HVAC - Manual
DTC B0193
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions Diagnostic Procedure Instructionsprovides 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 speed control from the HVAC control module, battery positive and ground circuits enable the blower motor control module to operate. The HVAC control module provides a pulse width modulation (PWM) signal to the blower motor control module in order to command the blower motor speed. The blower motor control module transfers the PWM signal into a corresponding blower motor voltage. The voltage resides between 2-13 V and changes linear to the height of the PWM signal.
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 floating.
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.
Reference Information
Schematic Reference
HVAC Schematics HVAC - Manual
Connector End View Reference
Component Connector End Views Sunshade - Left (D6I)
Description and Operation
Manual HVAC Description and Operation HVAC - Manual
Electrical Information Reference
* Circuit Testing Circuit Testing
* Connector Repairs Connector Repairs
* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs Wiring Repairs
Scan Tool Reference
Control Module References Control Module Referencesfor scan tool information
Circuit/System Testing
1. Ignition OFF, disconnect the X1 harness connector at the K8 blower motor control module. It may take up to 2 minutes for all vehicle systems to power down.
2. Test for less than 10 ohm between the ground circuit terminal 5 and ground.
• If 10 ohm or greater
1. Ignition OFF.
2. Test for less than 2 ohm in the ground circuit end to end.
• If 2 ohm or greater, repair the open/high resistance in the circuit.
• If less than 2 ohm, repair the open/high resistance in the ground connection.
• If less than 10 ohm
3. Ignition ON, verify a test lamp illuminates between B+ circuit terminal 6 and ground.
• If the test lamp does not illuminate and the circuit fuse is good
1. Ignition OFF.
2. Test for less than 2 ohm in the B+ circuit end to end.
• If 2 ohm or greater, repair the open/high resistance in the circuit.
• If less than 2 ohm, 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
1. Ignition OFF.
2. 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.
• If infinite resistance, replace the K8 blower motor control module.
• If the test lamp illuminates
4. Connect a DMM between the control circuit X1 terminal 3 and the B+ circuit terminal 6.
5. Verify the proper voltages when changing the blower speed positions.
* OFF 12.0 V-11.0 V
* Low 11.0 V-9.0 V
* Med 1 9.0 V-7.0 V
* Med 2 7.0 V-6.0 V
* Med 3 6.0 V-5.0 V
* Med 4 5.0 V-3.0 V
* HI 2.0 V-1.0 V
• If not within the specified range
1. Ignition OFF, disconnect the harness connector at the K33 HVAC control module.
2. Test for less than 1 V between the control circuit terminal 3 and ground.
• If 1 V or greater, repair the short to voltage on the circuit.
• If less than 1 V
3. 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.
• If within the specified range
6. Connect the X1 harness connector at the K8 blower motor control module. Disconnect the harness connector at the M8 blower motor.
7. Connect a DMM between the control circuit terminal A and B+.
8. Verify the proper voltages when changing the blower speed positions.
* OFF 0 V
* Low 2.0 V-3.0 V
* Med 1 3.0 V-4.5 V
* Med 2 4.5 V-6.5 V
* Med 3 6.5 V-8.5 V
* Med 4 8.5 V-10.0 V
* HI 10.0 V-12.0 V
• If not within the specified range
1. Ignition OFF, disconnect the harness connector X2 at the K8 blower motor control module.
2. 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
3. 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.
• If within the specified range
9. Verify a test lamp illuminates between B+ circuit terminal B and ground.
• If the test lamp does not illuminate
1. Ignition OFF.
2. Test for less than 2 ohm in the B+ circuit end to end.
• If 2 ohm or greater, repair the open/high resistance in the circuit.
• If less than 2 ohm.
3. Test for infinite resistance between the B+ circuit and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance, replace the M8 blower motor.
• If the test lamp illuminates
10. All OK.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.
* HVAC Component Replacement Reference HVAC Component Replacement Reference
* Control Module References Control Module Referencesfor HVAC control module replacement, setup, and programming