Pinpoint Test X: The Blower Motor Does Not Operate Correctly - EMTC

Climate Control System

Pinpoint Tests

Pinpoint Test X: The Blower Motor Does Not Operate Correctly - EMTC

Refer to Wiring Diagram Set 54, Manual Climate Control System for schematic and connector information. Diagrams By Number

Normal Operation

The blower motor is provided a ground through the entire blower resistor in the lowest blower setting. In MED-LO and MED-HI the resistor gets a ground from the blower motor switch. In HI, the blower motor is grounded directly through the blower motor switch. The blower switch is provided a ground.

- DTC B10AF:11 (Blower Fan Relay: Circuit Short to Ground) - the module senses no voltage on the relay coil ground circuit when the module is not grounding the circuit for more than 2 seconds.

This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Blower motor resistor
- HVAC module

PINPOINT TEST X: THE BLOWER MOTOR DOES NOT OPERATE CORRECTLY - EMTC

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X1 CHECK THE HVAC MODULE FOR DTCs

- Ignition ON.
- Check the HVAC module for DTCs.
- Is DTC B10AF:11 present?

Yes
GO to X2.

No
GO to X3.

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X2 CHECK THE BLOWER MOTOR RELAY COIL SWITCHED GROUND CIRCUIT FOR A SHORT TO GROUND

- Ignition OFF.
- Disconnect: Blower Motor Relay.
- Disconnect: HVAC Module - EMTC C294B.
- Measure the resistance between blower motor relay socket pin 2, circuit CH123 (VT/GN) and ground.

- Is the resistance greater than 10,000 ohms?

Yes
GO to X12.

No
REPAIR circuit CH123 (VT/GN) for a short to ground. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.

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X3 CHECK THE BLOWER MOTOR OPERATION

- Ignition ON.
- Select PANEL on the HVAC controls.
- Select all blower speed positions.
- Does the blower motor operate in any position?

Yes
If the blower motor does not operate in HI setting only, GO to X4.

If the blower motor does not operate in LO setting only, GO to X5.

If the blower motor does not operate in MED-LO or MED-HI setting only, GO to X6.

If the blower motor operates in HI setting only, GO to X8.

If the blower motor operates in LO setting only, GO to X9.

For all other symptoms, GO to X10.

No
GO to Pinpoint Test W. Pinpoint Test W: The Blower Motor is Inoperative - EMTC

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X4 CHECK THE BLOWER MOTOR GROUND CIRCUIT FOR AN OPEN

- Ignition OFF.
- Disconnect: HVAC Module - EMTC C294B.
- Disconnect: Blower Motor C2004.
- Measure the resistance between HVAC module - EMTC C294B-2, circuit CH426 (YE/OG), harness side and blower motor C2004-2, circuit CH426 (YE/OG), harness side.

- Is the resistance less than 5 ohms?

Yes
GO to X12.

No
REPAIR circuit CH426 (YE/OG) for an open. TEST the system for normal operation.

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X5 CHECK BLOWER MOTOR RESISTOR GROUND CIRCUIT FOR AN OPEN

- Ignition OFF.
- Disconnect: Blower Motor Resistor C2185.
- Measure the resistance between blower motor resistor C2185-4, circuit GD138 (BK/WH), harness side and ground.

- Is the resistance less than 5 ohms?

Yes
INSTALL a new blower motor resistor. REFER to Climate Control Service and Repair. TEST the system for normal operation.

No
REPAIR circuit GD138 (BK/WH) for an open. TEST the system for normal operation.

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X6 CHECK THE BLOWER MOTOR SWITCH

NOTICE: The following step uses a test light to simulate normal circuit loads. Use only the test light recommended in the Special Tools table at the beginning or equivalent. To avoid connector terminal damage, use the Flex Probe Kit for the test light probe connection to the vehicle. Do not use the test light probe directly on any connector.

- Ignition OFF.
- Disconnect: Blower Motor Resistor C2185.
- Ignition ON.

For MED-LO inoperative

- For MED-LO inoperative: With the blower motor switch in the MED-LO speed position, connect the 12-volt test light between blower motor resistor C2185-2, circuit CH426 (YE/OG), harness side and blower motor resistor C2185-1, circuit CH428 (GN/WH), harness side.

For MED-HI inoperative

- For MED-HI inoperative: With the blower motor switch in the MED-HI speed position, connect the 12-volt test light between blower motor resistor C2185-2, circuit CH426 (YE/OG), harness side and blower motor resistor C2185-3, circuit CH429 (GY/BN), harness side.
- Does the test light illuminate?

Yes
INSTALL a new blower motor resistor. REFER to Climate Control Service and Repair. TEST the system for normal operation.

No
GO to X7.

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X7 CHECK THE BLOWER MOTOR SWITCH TO BLOWER MOTOR RESISTOR CIRCUITS FOR AN OPEN

- Ignition OFF.
- Disconnect: HVAC Module - EMTC C294B.

For MED-LO inoperative

- For MED-LO inoperative, measure the resistance between HVAC module - EMTC C294B-4, circuit CH428 (GN/WH), harness side and blower motor resistor C2185-1, circuit CH428 (GN/WH), harness side.

For MED-HI inoperative

- For MED-HI inoperative, measure the resistance between HVAC module - EMTC C294B-3, circuit CH429 (GY/BN), harness side and blower motor resistor C2185-3, circuit CH429 (GY/BN), harness side.
- Is the resistance less than 5 ohms?

Yes
GO to X12.

No
REPAIR circuit CH428 (GN/WH) or CH429 (GY/BN) for an open. TEST the system for normal operation.

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X8 CHECK THE BLOWER MOTOR GROUND CIRCUIT TO THE BLOWER MOTOR RESISTOR FOR AN OPEN

- Ignition OFF.
- Disconnect: Blower Motor Resistor C2185.
- Disconnect: Blower Motor C2004.
- Measure the resistance between blower motor resister C2185-2, circuit CH426 (YE/OG), harness side and blower motor C2004-2, circuit CH426 (YE/OG), harness side.

- Is the resistance less than 5 ohms?

Yes
GO to X12.

No
REPAIR circuit GD138 (BK/WH) for an open. TEST the system for normal operation.

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X10 CHECK THE BLOWER MOTOR RESISTOR CIRCUITS FOR A SHORT TO GROUND

- Ignition OFF.
- Disconnect: Blower Motor C2004.
- Disconnect: Blower Motor Resistor C2185.
- Disconnect: HVAC Module - EMTC C294B.
- Measure the resistance between ground and blower motor resistor:
- C2185-1, circuit CH428 (GN/WH), harness side.
- C2185-2, circuit CH426 (YE/OG), harness side.
- C2185-3, circuit CH429 (GY/BN), harness side.

- Are the resistances greater than 10,000 ohms?

Yes
GO to X11.

No
REPAIR the affected circuit for a short to ground. TEST the system for normal operation.

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X11 CHECK THE BLOWER MOTOR RESISTOR CIRCUITS FOR SHORTS TOGETHER

- Measure the resistance between blower motor resistor C2185, harness side using the following chart:

- Are the resistances greater than 10,000 ohms?

Yes
CARRY OUT the Blower Motor Resistor component test. If the resistor tests OK, GO to X12. Climate Control System

No
REPAIR the affected circuits. TEST the system for normal operation.

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X12 CHECK THE HVAC MODULE CONNECTION

- Inspect the HVAC module connectors for:
- corrosion
- pushed-out terminals
- damaged terminals
- Connect and correctly seat all the HVAC module connectors.
- Clear the DTCs.
- Enter the following diagnostic mode on the scan tool: Self-Test - HVAC Module.
- Operate the system and verify the concern is still present.
- Is the concern still present?

Yes
INSTALL a new HVAC module. REFER to Climate Control Service and Repair. TEST the system for normal operation.

No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.

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