GM Service Manual Online
For 1990-2009 cars only

Object Number: 308551  Size: SF
HVAC Components
HVAC Air Delivery/Temperature Control Schematics
HVAC Air Delivery/Temperature Control Schematics
Handling Electrostatic Discharge Sensitive Parts Notice
Power Distribution Schematics
Power Distribution Schematics

Circuit Description

The heater-A/C control receives a LH electric actuator position signal from the LH electric actuator. The LH electric actuator position sensor is a potentiometer that is tied to a 5V source through circuit 1217 (PNK/BLK) and to ground through circuit 61(YEL), both from the heater-A/C control. The variable output from the potentiometer feeds back a position signal through circuit 1218 (BRN/WHT) to a pull-up resistor in the heater-A/C control. This signal relates to the position of the LH electric actuator. This signal is used to determine the necessary drive signal to the LH electric actuator motor to provide the proper air mix door position.

Conditions for Setting the DTC

The heater-A/C control performs an internal check on the LH electric actuator position and determines that circuit 1218 (BRN/WHT) is shorted to B+ or shorted to ground.

Action Taken When the DTC Sets

The heater-A/C control stores DTC B0361 in memory.

Conditions for Clearing the DTC

    • A short to B+ or short to ground is no longer present in circuit 1218 (BRN/WHT).
    • Under all fault conditions, the ignition switch must be cycled from on to off, back to on before this DTC can change from current to history.
    • A history DTC will clear after 100 drive cycles if the condition for this malfunction is no longer present.
    • Using a scan tool.

Diagnostic Aids

The following conditions may cause DTC B0361 to set:

    •  A short to ground in circuit 1217 (PNK/BLK) or 1218 (BRN/WHT).
    •  A short to B+ in circuit 61(YEL), 1217 (PNK/BLK), or 1218 (BRN/WHT).
    • An open in circuit 1217 (PNK/BLK) or 1218 (BRN/WHT).

Test Description

The number(s) below refer to the step number(s) on the diagnostic table.

  1. This test checks if the heater-A/C control 5V supply is getting through circuit 1217 (PNK/BLK).

  2. This test checks if the heater-A/C control ground is getting through circuit 61.

  3. This test checks if the heater-A/C control 5V supply is getting through circuit 1218 (BRN/WHT).

Step

Action

Value(s)

Yes

No

1

Was the heater-A/C control diagnostic system check performed?

--

Go to Step 2

Go to Diagnostic System Check

2

  1. Turn the ignition switch off.
  2. Disconnect the LH electric actuator electrical connector.
  3. Turn the ignition switch on.
  4. Use a digital multimeter (DMM) to measure the voltage between the driver (LH) electric actuator harness connector terminal 10 and ground.

Is the measured voltage within the specified range?

4.5-5.5V

Go to Step 3

Go to Step 6

3

Use a DMM to measure the voltage between the LH electric actuator harness connector terminal 7 and terminal 10.

Is the measured voltage within the specified range?

4.5-5.5V

Go to Step 4

Go to Step 9

4

Use a DMM to measure the voltage between the LH electric actuator harness connector terminal 7 and terminal 9.

Is the measured voltage within the specified range?

4.5-5.5V

Go to Step 5

Go to Step 12

5

Replace the LH electric actuator. Refer to Temperature Actuator Replacement (LH (Driver)) .

Is the repair complete?

--

System OK

--

6

Check circuit 1217 (PNK/BLK) for a short to B+ or short to ground.

Is there a short to B+ or short to ground in circuit 1217 (PNK/BLK) ?

--

Go to Step 7

Go to Step 8

7

Locate and repair the short to B+ or short to ground in circuit 1217(PNK/BLK) .

Is the repair complete?

--

System OK

--

8

  1. Check for a poor connection or open in circuit 1217 (PNK/BLK) .
  2. Replace the heater-A/C control if circuit 1217 (PNK/BLK) is OK . Refer to Control Assembly Replacement .

Is the repair complete?

--

System OK

--

9

Check circuit 61 (YEL) for a short to B+.

Is there a short to B+ in circuit 61 (YEL)?

--

Go to Step 10

Go to Step 11

10

Locate and repair short to B+ in circuit 61 (YEL).

Is the repair complete?

--

System OK

--

11

  1. Check for a poor connection or open in circuit 61 (YEL).
  2. Replace the heater-A/C control if circuit 61 (YEL) is OK . Refer to Control Assembly Replacement .

Is the repair complete?

--

System OK

--

12

  1. Check for a short to B+ or short to ground in circuit 1218 (BRN/WHT).
  2. Replace the heater-A/C control if circuit 1218 is OK . Refer to Control Assembly Replacement .

Is the repair complete?

--

System OK

--