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 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 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 (DH6)
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 References for scan tool information
Circuit/System Testing
1. Ignition OFF, disconnect the X1 harness connector at the K8 Blower Motor Control Module, ignition ON.
2. Verify that a test lamp illuminates between the B+ circuit terminal 6 X1 at the K8 Blower Motor Control Module harness connector 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
3. Disconnect the harness connector at the M8 Blower Motor and the X2 harness connector at the K8 Blower Motor Control Module.
4. Test for infinite resistance between the B+ circuit terminal 1 X2 and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance
5. Connect the harness connector at the M8 Blower Motor.
6. Install a 40 A fused jumper wire between the B+ circuit terminal 1 X2 and B+ and verify the fuse is good.
• If the fuse is open, replace the M8 Blower Motor.
• If the fuse is good, replace the K8 Blower Motor Control Module.
• If the test lamp illuminates
3. Verify that a test lamp illuminates between the B+ circuit terminal 6 X1 and ground circuit terminal 5 X1.
• If the test lamp does not illuminate
Repair the open/high resistance in the circuit.
• If the test lamp illuminates
4. Ignition OFF, disconnect the X2 harness connector at the K33 HVAC Control Module, ignition ON.
5. Test for less than 0.3 V between the control circuit terminal 3 X1 at the K8 Blower Motor Control Module harness connector and ground.
• If greater than 0.3 V
Repair the short to voltage on the circuit.
• If less than 0.3 V
6. Ignition OFF.
7. Test for infinite resistance between the control circuit terminal 3 X1 at the K8 Blower Motor Control Module harness connector and ground.
• If less than infinite resistance
Repair the short to ground on the circuit.
• If infinite resistance
8. Test for less than 5 ohms between the K33 HVAC Control Module control circuit terminal 15 X2 and control circuit terminal 3 X1 at the K8 Blower Motor Control Module harness connector.
• If greater than 5 ohms
Repair the open/high resistance in the circuit.
• If less than 5 ohms
9. Replace the K8 Blower Motor Control Module and verify the DTC does not reset.
• If DTC resets
Replace the K33 HVAC Control Module.
• If DTC does not reset
10. All OK.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.
* Control Module References Control Module References for HVAC control module replacement, programming and setup