B0193
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 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 speed is controlled by the HVAC Control Module using a PWM signal circuit. Using internal logic the blower motor interprets the PWM signal to operate at the desired speed command chosen by the user.
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
The current design of this motor does not allow for bench testing. The motor will not operate by simply applying power and ground.
Inspect the motor shaft for rust or other foreign material which may prohibit proper motor operation.
Check for PIs or TSBs, and refer to Testing for Intermittent Conditions and Poor Connections in the Electrical Information Reference section of this document.
Reference Information
Schematic Reference
HVAC Schematics Electrical Diagrams
Connector End View Reference
Component Connector End Views Fuel Pump and Level Sensor Assembly
Description and Operation
Automatic HVAC Description and Operation HVAC - Automatic
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 References for scan tool information
Circuit/System Testing
1. Ignition OFF and all vehicle systems off, disconnect the harness connector at the M8 Blower Motor. It may take up to 2 minutes for all vehicle systems to power down.
2. Test for less than 10 ohms between the ground circuit terminal 1 and ground.
• If 10 ohms or greater
1. Ignition OFF.
2. Test for less than 2 ohms in the ground circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, repair the open/high resistance in the ground connection.
• If less than 10 ohms
3. Ignition ON.
4. Verify a test lamp illuminates between the B+ circuit terminal 3 and ground.
• If the test lamp does not illuminate and the circuit fuse is good
1. Ignition OFF.
2. Test for less than 2 ohms in the B+ circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, 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 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
5. Connect a test lamp between the control circuit terminal 2 and ground.
6. Verify the test lamp illuminates and there is a noticeable change when moving between commanded fan speeds.
• If there is not a noticeable change when moving between commanded fan speeds
1. Ignition OFF, disconnect the X2 harness connector at the K33 HVAC 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.
4. Test for less than 2 ohms in the control circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms replace the K33 HVAC Control Module.
• If there is a noticeable change when moving between commanded fan speeds
7. Test or replace the M8 Blower Motor.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the repair.
* HVAC Component Replacement Reference Removal and Replacement
* Control Module References Control Module References for HVAC Control Module replacement, programming, and setup.