For 1990-2009 cars

### 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 Descriptor

DTC B0193 01: Front Blower Motor Speed Circuit Short to Battery
DTC B0193 06: Front Blower Motor Speed Circuit Short to Ground or Open

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
Blower Motor Control Module B+ | B0193 06 | B0193 06 | -- | --
Blower Motor Control Module Control | B0193 06 | B0193 06 | B0193 01 | --
Blower Motor Control Module Ground | -- | B0193 06 | -- | --

### 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

#### Connector End View Reference

Component Connector End Views

#### 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, disconnect the X2 harness connector at the K33 HVAC Control Module and the X2 harness connector at the K8 Blower Motor Control Module.
2. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal 6 (X2) at the K8 Blower Motor Control Module harness connector and ground.

⇒ | If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.

3. Verify that a test lamp illuminates between the B+ circuit terminal 6 (X2) and ground circuit terminal 5 (X2).

⇒ | If the test lamp does not illuminate, test the ground circuit for an open/high resistance.

4. Test for less than 0.3 V between the control circuit terminal 15 (X2) at the K33 HVAC Control Module harness connector and ground.

⇒ | If greater than the specified range, test the control circuit for a short to voltage.

5. Ignition OFF, test for infinite resistance between the control circuit terminal 15 (X2) at the K33 HVAC Control Module harness connector and ground.

⇒ | If less than the specified range, test the control circuit for a short to ground.

6. Test for less than 5 Ω between the K33 HVAC Control Module control circuit terminal 15 (X2) and control circuit terminal 3 (X2) at the K8 Blower Motor Control Module harness connector.

⇒ | If greater than the specified value, test the control circuit for an open/high resistance.

7. If all circuits test normal, replace the K8 Blower Motor Control Module and verify the DTC does not reset.

⇒ | If the DTC resets, replace the K33 HVAC Control Module.

### Repair Instructions

Perform the Diagnostic Repair Verification

• | Heater and Blower and Air Conditioning Control Module Replacement

• | Control Module References