2006 MERCEDES-BENZ SPRINTER heating

TEST ACTION APPLICABILITY
3WARNING: NEVER OPERATE THE HEATER IN AN ENCLOSED AREA
THAT DOES NOT HAVE EXHAUST VENTILATION FACILITIES. ALWAYS
VENT THE EXHAUST WHEN OPERATING THE HEATER. FAILURE TO
FOLLOW THESE INSTRUCTIONS CAN RESULT IN PERSONAL INJURY
OR DEATH.
WARNING: ALLOW THE HEATER ASSEMBLY TO COOL BEFORE PER-
FORMING A COMPONENT INSPECTION/REPAIR/REPLACEMENT. FAIL-
URE TO FOLLOW THESE INSTRUCTIONS CAN RESULT IN PERSONAL
INJURY OR DEATH.
Turn the ignition on.
With the DRBIIIt, read Automatic Temperature Control DTCs.
Are any DTCs present?All
Ye s!Refer to Heating & A/C information for the related symptom(s).
Perform HEATER VERIFICATION TEST - VER 1.
No!Allow heater assembly to cool. Inspect the fuel line, air intake and
exhaust, and coolant hoses for restrictions, obstructions, loose
clamps, leakage, etc. Repair as necessary. Check the harness
connectors and grounds. Clean and repair as necessary.
Perform HEATER VERIFICATION TEST - VER 1.
71
CABIN HEATER
A. HEATER PRE-TEST ÐContinued

Symptom List:
HEATER IN LOCKOUT MODE
HEATER OVERHEATED
SUCCESSIVE OVERHEATING
Test Note: All symptoms listed above are diagnosed using the same tests.
The title for the tests will be HEATER IN LOCKOUT MODE.
When Monitored and Set Condition:
HEATER IN LOCKOUT MODE
When Monitored: During heater activation and operation.
Set Condition: This DTC will set if multiple attempts to start the heater have failed or if
successive overheating occurs.
HEATER OVERHEATED
When Monitored: After heater activation, when the system is in a steady state of
operation.
Set Condition: This DTC will set if the Temperature Sensor's resistance or Overheating
Sensor's resistance is not within the expected parameters (coolant temperature in the
heater module exceeds 105ÉC [221ÉF]).
SUCCESSIVE OVERHEATING
When Monitored: After heater activation, when the system is in a steady state of
operation.
Set Condition: This DTC will set if successive overheating occurs.
POSSIBLE CAUSES
CABIN HEATER ASSEMBLY OR HEATER BOOSTER ASSEMBLY
HEATER'S COOLANT HOSES RESTRICTED/LEAKING/DAMAGED
ENGINE'S COOLING SYSTEM FAULT
CABIN HEATER OR HEATER BOOSTER CONTROL UNIT
HEATER OVERHEATED/SUCCESSIVE OVERHEATING CLEARED, ADDITIONAL DTC(S)
PRESENT
93
CABIN HEATER

TEST ACTION APPLICABILITY
4WARNING: NEVER OPERATE THE HEATER IN AN ENCLOSED AREA
THAT DOES NOT HAVE EXHAUST VENTILATION FACILITIES. ALWAYS
VENT THE EXHAUST WHEN OPERATING THE HEATER. FAILURE TO
FOLLOW THESE INSTRUCTIONS CAN RESULT IN PERSONAL INJURY
OR DEATH.
Refill the cooling system in accordance with the Service Information.
Start the engine.
Allow the engine to reach normal operating temperature.
Turn the engine off.
Allow the engine coolant to cool down to a temperature of 50ÉC (122ÉF).
Start the engine.
Allow the engine to reach normal operating temperature.
Turn the engine off.
View repairAll
Repair
Go To 5
5WARNING: NEVER OPERATE THE HEATER IN AN ENCLOSED AREA
THAT DOES NOT HAVE EXHAUST VENTILATION FACILITIES. ALWAYS
VENT THE EXHAUST WHEN OPERATING THE HEATER. FAILURE TO
FOLLOW THESE INSTRUCTIONS CAN RESULT IN PERSONAL INJURY
OR DEATH.
NOTE: The heater's control unit will store up to five DTCs in its memory.
NOTE: If the heater's control unit detects a new fault in the system, one that
is not already stored in its memory, it will clear the oldest of the five stored
DTCs, and it will store the new fault's DTC.
NOTE: If the heater's control unit detects a reoccurrence of a stored fault,
it will overwrite that fault's DTC with the most recent occurrence.
Turn the ignition on.
Verify that the Cabin Heater or Heater Booster is switched off.
Set the blend control to the max heat position and the mode control to the floor
position.
Start the engine. Allow the engine to idle.
With the DRBIII, monitor for Cabin Heater or Heater Booster Module DTCs while
performing the following step.
NOTE: Do not disconnect the vehicle's battery or the heater's main power
supply while the heater is in operation or in run-down mode. Failure to
follow these instructions can result in excess emissions from the heater
during heater operation.
Switch the Cabin Heater or Heater Booster on. If necessary, allow the heater to run
through at least one cycle of operation (approximately 10 minutes), and then turn the
heater off.
Turn the engine off.
Does the DRBIIItdisplay any DTCs?All
Overheating Related DTC(s) Reset
Replace the Cabin Heater Assembly or Heater Booster Assembly
in accordance with the Service Information.
Perform HEATER VERIFICATION TEST - VER 1.
Ovrheatng DTC(s) clear, Other DTC(s) Set
Return to the symptom list and choose the symptom(s).
Perform HEATER VERIFICATION TEST - VER 1.
No DTCs Present
Test Complete.
95
CABIN HEATER
HEATER IN LOCKOUT MODE ÐContinued

Symptom List:
OVERHEATING SENSOR OPEN
OVERHEATING SENSOR SHORTED
Test Note: All symptoms listed above are diagnosed using the same tests.
The title for the tests will be OVERHEATING SENSOR OPEN.
When Monitored and Set Condition:
OVERHEATING SENSOR OPEN
When Monitored: During heater activation and operation.
Set Condition: This DTC will set if the Overheating Sensor's resistance is not within the
expected parameters.
OVERHEATING SENSOR SHORTED
When Monitored: During heater activation and operation.
Set Condition: This DTC will set if the Overheating Sensor's resistance is not within the
expected parameters.
POSSIBLE CAUSES
OVERHEATING SENSOR
TEST ACTION APPLICABILITY
1WARNING: NEVER OPERATE THE HEATER IN AN ENCLOSED AREA
THAT DOES NOT HAVE EXHAUST VENTILATION FACILITIES. ALWAYS
VENT THE EXHAUST WHEN OPERATING THE HEATER. FAILURE TO
FOLLOW THESE INSTRUCTIONS CAN RESULT IN PERSONAL INJURY
OR DEATH.
WARNING: ALLOW THE HEATER ASSEMBLY TO COOL BEFORE PER-
FORMING A COMPONENT INSPECTION/REPAIR/REPLACEMENT. FAIL-
URE TO FOLLOW THESE INSTRUCTIONS CAN RESULT IN PERSONAL
INJURY OR DEATH.
CAUTION: DO NOT PERFORM THIS TEST UNLESS DIRECTED HERE BY
THE HEATER PRE-TEST. ALWAYS PERFORM THE HEATER PRE-TEST
PRIOR TO PERFORMING ANY OTHER TEST FOR THE RESULT TO BE
VALID.
Turn the ignition off.
View repairAll
Repair
Replace the Cabin Heater Assembly or Heater Booster Assembly
in accordance with the Service Information.
Perform HEATER VERIFICATION TEST - VER 1.
97
CABIN HEATER

Symptom:
A/C COMPRESSOR CONTROL HIGH OR OPEN (ACTIVE)
POSSIBLE CAUSES
A/C COMPRESSOR CLUTCH CONTROL CIRCUIT SHORTED TO VOLTAGE
A/C COMPRESSOR CLUTCH
A/C COMPRESSOR CLUTCH CONTROL CIRCUIT OPEN
AUTOMATIC TEMPERATURE CONTROL (ATC)
TEST ACTION APPLICABILITY
1 Turn the ignition off.
NOTE: Check connectors - Clean/repair as necessary.
Disconnect the A/C Compressor Clutch harness connector.
Turn the ignition on.
Press the Air Conditioning switch off.
Measure the voltage of the A/C Compressor Clutch Control circuit.
Is the voltage above 10.0 volts?All
Ye s!Go To 2
No!Go To 4
2 Turn the ignition off.
NOTE: Check connectors - Clean/repair as necessary.
Disconnect the Automatic Temperature Control (ATC) C1 harness connector.
Disconnect the A/C Compressor Clutch harness connector.
Turn the ignition on.
Measure the voltage of the A/C Compressor Clutch Control circuit.
Is the voltage above 0.2 volts?All
Ye s!Repair the A/C Compressor Clutch Control circuit for a short to
voltage.
Perform BODY VERIFICATION TEST - VER 1.
No!Go To 3
3 Turn the ignition off.
NOTE: Check connectors - Clean/repair as necessary.
Reconnect the Automatic Temperature Control (ATC) C1 harness connector.
Reconnect the A/C Compressor Clutch harness connector.
Verify that the A/C Compressor Clutch Ground is clean and tight.
Turn the ignition on.
With the DRBIIIt, erase DTCs.
Turn the ignition off, wait 5 seconds, then turn the ignition on.
With the DRBIIIt, read Automatic Temperature Control DTCs.
Does the DRBIIItdisplay: A/C COMPRESSOR CONTROL HIGH OR OPEN?All
Ye s!Replace the A/C Compressor Clutch in accordance with the
Service Information.
Perform BODY VERIFICATION TEST - VER 1.
No!Test Complete.
128
HEATING & A/C

TEST ACTION APPLICABILITY
4 Turn the ignition off.
NOTE: Check connectors - Clean/repair as necessary.
Disconnect the Automatic Temperature Control (ATC) C1 harness connector.
Disconnect the A/C Compressor Clutch harness connector.
Measure the resistance of the A/C Compressor Clutch Control circuit between the
Automatic Temperature Control (ATC) C1 harness connector and the A/C Compres-
sor Clutch harness connector.
Is the resistance below 5.0 ohms?All
Ye s!Replace the Automatic Temperature Control (ATC) in accordance
with the Service Information.
Perform BODY VERIFICATION TEST - VER 1.
No!Repair the A/C Compressor Clutch Control circuit for an open.
Perform BODY VERIFICATION TEST - VER 1.
129
HEATING & A/C
A/C COMPRESSOR CONTROL HIGH OR OPEN (ACTIVE) ÐContinued

Symptom List:
A/C COMPRESSOR CONTROL HIGH OR OPEN (STORED)
A/C COMPRESSOR CONTROL SHORTED LOW (STORED)
AIR OUTLET TEMP SENSOR HIGH OR OPEN (STORED)
AIR OUTLET TEMP SENSOR SHORTED LOW (STORED)
AUX FAN RELAY CONTROL HIGH OR OPEN (STORED)
AUX FAN RELAY CONTROL SHORTED LOW (STORED)
BLOWER STAGE 1 HIGH OR OPEN (STORED)
BLOWER STAGE 1 SHORTED LOW (STORED)
CABIN HEATER CONTROL HIGH OR OPEN (STORED)
CABIN HEATER CONTROL SHORTED LOW (STORED)
CIRC PUMP CONTROL HIGH OR OPEN (STORED)
CIRC PUMP CONTROL SHORTED LOW (STORED)
EVAP TEMP SENSOR HIGH OR OPEN (STORED)
EVAP TEMP SENSOR SHORTED LOW (STORED)
NO COMMUNICATION BUS (STORED)
NO COMMUNICATION WITH ECM (STORED)
NO COMMUNICATION WITH IC (STORED)
RECIRC AIR SOLENOID CONTROL HIGH OR OPEN (STORED)
RECIRC AIR SOLENOID CONTROL SHORTED LOW (STORED)
REFRIG PRESS SENSOR HIGH OR OPEN (STORED)
REFRIG PRESS SENSOR SHORTED LOW (STORED)
WATER CYCLE VALVE CONTROL HIGH OR OPEN (STORED)
WATER CYCLE VALVE CONTROL SHORTED LOW (STORED)
Test Note: All symptoms listed above are diagnosed using the same tests.
The title for the tests will be A/C COMPRESSOR CONTROL
HIGH OR OPEN (STORED).
When Monitored and Set Condition:
NO COMMUNICATION BUS (STORED)
When Monitored: With the ignition on.
Set Condition: This DTC will set if the Automatic Temperature Control (ATC) fails to
receive all module messages.
NO COMMUNICATION WITH ECM (STORED)
When Monitored: With the ignition on.
Set Condition: This DTC will set if the Automatic Temperature Control (ATC) fails to
receive all messages from the ECM.
130
HEATING & A/C

NO COMMUNICATION WITH IC (STORED)
When Monitored: With the ignition on.
Set Condition: This DTC will set if the Automatic Temperature Control (ATC) fails to
receive all messages from the Instrument Cluster.
POSSIBLE CAUSES
CHECK FOR ACTIVE AUTOMATIC TEMPERATURE CONTROL (ATC) DTCS
INTERMITTENT CONDITION
TEST ACTION APPLICABILITY
1NOTE: All of the following criteria must be met in order to successfully run
the ATC Function Test.
Place the shift lever in Park.
Turn the ignition on.
With the DRBIIIt, record and erase ATC DTC's.
Start the engine. Allow the engine to reach normal operating temperature.
Set the blower to high speed.
Press the Air Conditioning switch On.
With the DRBIIIt, verify that the ambient temperature is above 59ÉF (15ÉC), the
refrigerant pressure is between 29 and 348 PSI (2 and 24 bar), the evaporator
temperature is above 36.5ÉF (2.5ÉC), and the coolant temperature is above 158ÉF
(70ÉC).
With the DRBIIItin Automatic Temperature Control (ATC), select System Tests and
select ATC Function Test. When the ATC Function Test is complete, proceed as
follows:
With the DRBIIIt, read the active ATC DTCs.
Does the DRBIIItdisplay any DTCs?All
Ye s!Return to the Heating & A/C Symptom List and choose the
symptom(s).
Perform BODY VERIFICATION TEST - VER 1.
No!Using the wiring diagram/schematic as a guide, inspect the
wiring and connectors related to the circuit(s) that caused the
original DTC(s) to set.
Perform BODY VERIFICATION TEST - VER 1.
131
HEATING & A/C
A/C COMPRESSOR CONTROL HIGH OR OPEN (STORED) ÐContinued