Pinpoint Test

CHECK THE HVAC MODULE FOR DTCs
1. Ignition ON.
2. Using a scan tool, perform the HVAC module self-test.
  Is DTC B10BA:12 present?
  - Yes: GO to 5 .
  - No : GO to 2 .

CHECK THE AUXILIARY BLOWER MOTOR RELAY COIL SWITCH GROUND CIRCUIT FOR A SHORT TO GROUND

Ignition OFF.
Disconnect: Auxiliary Blower Motor Relay.
Disconnect: HVAC Module C228B.

Measure:

BJB			Ground

Auxiliary Blower Motor Relay Socket			Ground
Pin	Circuit	Measurement / Action	Pin	Circuit
2	CH112 (VT/WH)		-	Ground

Is the resistance greater than 10, 000 ohms?

Yes: GO to 3 .
No : REPAIR the circuit.

CHECK THE AUXILIARY BLOWER MOTOR VOLTAGE CIRCUIT FOR A SHORT TO VOLTAGE

Disconnect: Auxiliary Blower Motor Speed Control.
Disconnect: Auxiliary Blower Motor.
Ignition ON.

Measure:

Auxiliary Blower Motor			Ground

C3021			Ground
Pin	Circuit	Measurement / Action	Pin	Circuit
2	CHA02 (BN/GN)		-	Ground

Is any voltage present?

Yes: REPAIR the circuit.
No : GO to 4 .

CHECK THE AUXILIARY BLOWER MOTOR GROUND CIRCUIT FOR A SHORT TO GROUND

Ignition OFF.

Measure:

Auxiliary Blower Motor			Ground

C3021			Ground
Pin	Circuit	Measurement / Action	Pin	Circuit
1	VHA19 (BN)		-	Ground

Is the resistance greater than 10, 000 ohms?

Yes: GO to 5 .
No : REPAIR the circuit.

CHECK THE AUXILIARY BLOWER MOTOR SPEED CONTROL COMMAND CIRCUIT FOR A SHORT TO VOLTAGE

Ignition OFF.
Disconnect: HVAC Module C228B.
Disconnect: Auxiliary Blower Motor Speed Control.
Ignition ON.

Measure:

Auxiliary Blower Motor Speed Control			Ground

C3002			Ground
Pin	Circuit	Measurement / Action	Pin	Circuit
5	VHA25 (BN/VT)		-	Ground

Is any voltage present?

Yes: REPAIR the circuit.
No : GO to 6 .

CHECK THE AUXILIARY BLOWER MOTOR SPEED CONTROL
1. Install a known good auxiliary blower motor speed controller.
2. Reconnect all disconnected connectors. Make sure they seat and latch correctly.
3. Ignition ON.
4. Operate the auxiliary blower motor.
  Does the auxiliary blower motor function correctly?
  - Yes: INSTALL a new auxiliary blower motor speed control. REFER to Auxiliary Blower Motor Speed Control .
  - No : GO to 7 .
CHECK FOR CORRECT HVAC MODULE OPERATION
1. Ignition OFF.
2. Disconnect and inspect all HVAC module connectors.
3. Repair:
  - corrosion (install new connector or terminals - clean module pins)
  - damaged or bent pins - install new terminals/pins
  - pushed-out pins - install new pins as necessary
4. Reconnect the HVAC module connectors. Make sure they seat and latch correctly.
5. Operate the system and determine if the concern is still present.
  Is the concern still present?
  - Yes: CHECK OASIS for any applicable TSBs . If a TSB exists for this concern, DISCONTINUE this test and FOLLOW TSB instructions. If no TSBs address this concern, INSTALL a new HVAC module. REFER to HEATING VENTILATION AIR CONDITIONING (HVAC) MODULE - EMTC or HEATING VENTILATION AIR CONDITIONING (HVAC) MODULE - DATC
  - No : The system is operating correctly at this time. The concern may have been caused by module connections. ADDRESS the root cause of any connector or pin issues.