Hummer H2. Manual — part 1940

DTC B0183 or B0188

Step

Action

Value

(s)

Yes

No

Schematic Reference: HVAC Schematics
Connector End View Reference: HVAC Connector End Views

1

Did you perform the HVAC Diagnostic
System Check?

-

Go to Step 2

Go to Diagnostic

System Check -

HVAC Systems -

Automatic

2

1. Install a scan tool.

2. Turn ON the ignition, with the engine

OFF.

3. With a scan tool, observe the

appropriate Solar Sensor parameter in
the Body Control Module data list.
Refer to one of the following
parameters:

z

Left Solar Sensor

z

Right Solar Sensor

Does the scan tool indicate that the
appropriate Solar Sensor parameter is within
the specified range?

5-250

Counts

Go to Testing for

Intermittent

Conditions and Poor

Connections in Wiring

Systems

Go to Step 3

3

1. Turn OFF the ignition.

2. Disconnect the sunload sensor

assembly.

3. Turn ON the ignition, with the engine

OFF.

4. With a scan tool, observe the

appropriate Solar Sensor data
parameter.

Does the scan tool indicate that the
appropriate Solar Sensor parameter is greater
than the specified value?

250

Counts

Go to Step 4

Go to Step 5

4

1. Turn OFF the ignition.

2. Connect a 3 amp fused jumper wire

between the signal circuit of the
sunload sensor assembly and the low
reference circuit of the sunload sensor
assembly.

3. Turn ON the ignition, with the engine

OFF.

5

Counts

2004 Hummer H2

2004 HVAC HVAC Systems - Automatic - Hummer H2

4. With a scan tool, observe the

appropriate Solar Sensor parameter.

Does the scan tool indicate that the
appropriate Solar Sensor parameter is less
than the specified value?

Go to Step 8

Go to Step 6

5

Test the solar signal circuit of the sunload
sensor assembly for a short to ground. Refer
to Circuit Testing and Wiring Repairs in
Wiring Systems.
Did you find and correct the condition?

-

Go to Step 12

Go to Step 9

6

Test the signal circuit of the sunload sensor
assembly for a short to voltage, a high
resistance, or an open. Refer to Circuit
Testing and Wiring Repairs in Wiring
Systems.
Did you find and correct the condition?

-

Go to Step 12

Go to Step 7

7

Test the low reference circuit of the sunload
sensor assembly for a high resistance or an
open. Refer to Circuit Testing and Wiring
Repairs in Wiring Systems.
Did you find and correct the condition?

-

Go to Step 12

Go to Step 9

8

Inspect for poor connections at the harness
connector of the sunload sensor assembly.
Refer to Testing for Intermittent
Conditions and Poor Connections and
Connector Repairs in Wiring Systems.
Did you find and correct the condition?

-

Go to Step 12

Go to Step 10

9

Inspect for poor connections at the harness
connector of the BCM. Refer to Testing for
Intermittent Conditions and Poor
Connections and Connector Repairs in
Wiring Systems.
Did you find and correct the condition?

-

Go to Step 12

Go to Step 11

10

Replace the sunload sensor assembly. Refer
to Sun Load Sensor Replacement .
Did you complete the replacement?

-

Go to Step 12

-

11

Replace the BCM. Refer to Body Control
Module Replacement in Body Control
System.Did you complete the replacement?

IMPORTANT:

Perform the set up procedure for the BCM.

-

Go to Step 12

-

1. Use the scan tool in order to clear the

DTCs.

2004 Hummer H2

2004 HVAC HVAC Systems - Automatic - Hummer H2

DTC B0229, B0414, B0424, OR B3770

Circuit Description

The following DTC's are for the HVAC door actuators:

z

B0229 is for the recirculation actuator.

z

B0414 is for the left air temperature actuator.

z

B0424 is for the right air temperature actuator.

z

B3770 is for the mode actuator.

The HVAC control module controls the HVAC door actuators to regulate the airflow through the HVAC
system. Each actuator consists of a stepper motor, a logic circuit, and a potentiometer. The potentiometer inside
the door actuator allows the module to monitor the current position of the actuator drive shaft. The module
supplies a 5 volt source voltage to the potentiometer on the 5 volt reference circuit. The module supplies ground
to the potentiometer through the low reference circuit. The HVAC control module monitors the voltage drop
across the potentiometer on the door position signal circuit. When the actuator shaft rotates, the voltage on the
door position signal circuit changes. The module converts the voltage value to a count value where 1 volt is
approximately equal to 51 counts.

The HVAC control module calibrates the travel range of the HVAC door actuators when it is initially powered
by the battery positive voltage circuit. During calibration, the module commands the actuators in each direction
until door travel is stopped. The module stores the minimum door positions and the maximum door positions of
each actuator into memory. The total travel range is calculated by subtracting the minimum door position from
the maximum door position. The door actuators can be calibrated again with a scan tool.

Conditions for Running the DTC

z

Battery voltage is 8.7-16.5 volts.

z

The ignition is ON.

Conditions for Setting the DTC

The DTC sets when one of the following conditions are present:

z

The actual door position value for the actuator is less than 5 counts.

z

The actual door position value for the actuator is greater than 250 counts.

z

The actuator fails calibration because the calculated travel range value is too great or too small.

12

2. Operate the vehicle within the

Conditions for Running the DTC as
specified in the supporting text.

Does the DTC reset?

-

Go to Step 2

System OK

2004 Hummer H2

2004 HVAC HVAC Systems - Automatic - Hummer H2

Action Taken When the DTC Sets

z

If the DTC sets because the actual door position value is out of range, the HVAC control module will
command the actuator to a default position.

z

If the DTC sets because the actuator failed a calibration, the HVAC control module will attempt to
calibrate the motor in the next transition from OFF to RUN mode.

Conditions for Clearing the DTC

z

The DTC will become history if the HVAC control module no longer detects the condition that set the
DTC.

z

The history DTC will clear after 100 fault free ignition cycles.

z

The DTC can be cleared with a scan tool.

Diagnostic Aids

z

If the condition is not present refer to Testing for Intermittent Conditions and Poor Connections in
Wiring Systems.

z

If the DTC sets following a calibration of the door actuator, inspect the door and the actuator for the
following conditions:

{

A misaligned actuator

{

Broken linkages or binding linkages

{

A broken door or a binding door

{

An obstruction that prevents the door from operating within the full range of motion

{

Missing seals to the door

{

Poor connections at the harness connector of the door actuator

Test Description

The numbers below refer to the step numbers on the diagnostic table.

3: Tests for the proper operation of the circuit in the low voltage range.

4: Tests for the proper operation of the circuit in the high voltage range. If the jumper fuse opens when
you perform this test, the circuit is shorted to ground.

5: Tests for a short to voltage in the 5-volt reference circuit.

6: Tests for a high resistance or for an open in the low reference circuit.

DTC B0229, B0414, B0424, or B3770

Step

Action

Values

Yes

No

Schematic Reference:HVAC Schematics
Connector End View Reference: HVAC Connector End Views

1

Did you perform the HVAC Diagnostic System
Check?

-

Go to Diagnostic

System Check -

2004 Hummer H2

2004 HVAC HVAC Systems - Automatic - Hummer H2