Air Delivery Improper
Diagnostic Instructions
Diagnostic Fault Information
Circuit
|
Short to Ground
|
Open/High Resistance
|
Short to Voltage
|
Signal Performance
|
Stepper Motors 12V Reference
|
B023A 02, B0223 06, B0233 06, B0418 06
|
B0223 06, B0233 06, B0418 06
|
-
|
-
|
Mode Actuator Control 1
|
B0233 06
|
B0233 06
|
B0233 01
|
1
|
Mode Actuator Control 2
|
B0233 06
|
B0233 06
|
B0233 01
|
1
|
Mode Actuator Control 3
|
B0233 06
|
B0233 06
|
B0233 01
|
1
|
Mode Actuator Control 4
|
B0233 06
|
B0233 06
|
B0233 01
|
1
|
1. Air Distribution Malfunction
|
|
| |
Circuit/System Description
With the defrost switch, air to foot well switch, air to
windscreen switch and the air to head area switch at the HVAC
controls, the wished air distribution flap position can be put in.
The selected value is sent to the HVAC control module via LIN-Bus.
The HVAC control module supplies a 12 V reference voltage to the
stepper motor and energizes the 4 stepper motor coils with a pulsed
ground signal. The stepper motor puts the air distribution flap
into the selected position.
Diagnostic Aids
Check the following mechanical fault sources:
| • |
Air distribution hoses/air
distributing ducts |
Reference Information
Schematic Reference
HVAC Schematics
Connector End View Reference
Component Connector End Views
Description and Operation
Manual HVAC Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Testing
| 1. |
Ignition ON, press and release
the switch for air distribution to head. Verify the scan tool Front
Defrost Switch parameter changes between Active and
Inactive. |
⇒ If the parameter
does not change
Replace the A26 HVAC Controls.
⇓ If the parameter
changes
| 2. |
Press and release the switch
for air distribution to face. Verify the scan tool Instrument Panel
Vents Switch parameter changes between Active and Inactive.
|
⇒ If the parameter
does not change
Replace the A26 HVAC Controls.
⇓ If the parameter
changes
| 3. |
Press and release the switch
for air distribution to floor. Verify the scan tool Floor Mode
Switch parameter changes between Active and Inactive. |
⇒ If the parameter
does not change
Replace the A26 HVAC Controls.
⇓ If the parameter
changes
| 4. |
Press and release the defrost
switch. Verify the scan tool Enhanced Defrost Switch parameter
changes between Active and Inactive. |
⇒ If the parameter
does not change
Replace the A26 HVAC Controls.
⇓ If the parameter
changes
| 5. |
Replace the M37 Mode Door
Actuator and verify the M37 Mode Door Actuator can be put into all
positions. |
⇒ If the M37 Mode
Door Actuator cannot be put into all positions
Replace the K33 HVAC Control Module.
⇓ If the M37 Mode
Door Actuator can be put into all positions
Repair Instructions
Perform the
Diagnostic Repair Verification after completing the diagnostic
procedure.
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