2006 MERCEDES-BENZ SPRINTER engine

Symptom:
CABIN HEATER CONTROL SHORTED LOW (ACTIVE)
POSSIBLE CAUSES
CABIN HEATER OR HEATER BOOSTER CONTROL UNIT
CABIN HEATER CONTROL CIRCUIT SHORTED TO GROUND
CABIN HEATER CONTROL CIRCUIT SHORTED TO GROUND CIRCUIT
CABIN HEATER CONTROL CIRCUIT SHORTED TO SENSOR GROUND CIRCUIT
AUTOMATIC TEMPERATURE CONTROL (ATC)
TEST ACTION APPLICABILITY
1 Turn the ignition off.
Disconnect the Cabin Heater or Heater Booster harness connector.
NOTE: 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: CABIN HEATER CONTROL SHORTED LOW?All
Ye s!Go To 2
No!Replace the Cabin Heater Assembly or the Heater Booster assem-
bly in accordance with the Service Information.
Perform BODY VERIFICATION TEST - VER 1.
2 Turn the ignition off.
Disconnect the Cabin Heater or Heater Booster harness connector.
Disconnect the Automatic Temperature Control (ATC) C1 harness connector.
Measure the resistance between ground and the Cabin Heater Control circuit.
Is the resistance below 30k ohms?All
Ye s!Repair the Cabin Heater Control circuit for a short to ground.
Perform BODY VERIFICATION TEST - VER 1.
No!Go To 3
150
HEATING & A/C

Symptom:
CIRC PUMP CONTROL HIGH OR OPEN (ACTIVE)
POSSIBLE CAUSES
CIRCULATION PUMP
CIRCULATION PUMP CONTROL CIRCUIT SHORTED TO VOLTAGE
AUTOMATIC TEMPERATURE CONTROL (ATC)
CIRCULATION PUMP CONTROL CIRCUIT OPEN
GROUND CIRCUIT OPEN
AUTOMATIC TEMPERATURE CONTROL (ATC)
TEST ACTION APPLICABILITY
1 Turn the ignition off.
Press the Residual Engine Heat Utilization (REST) switch off.
NOTE: Check connectors - Clean/repair as necessary.
Disconnect the Circulation Pump harness connector.
Connect a 12-volt test light between the Circulation Pump Control circuit and the
Ground circuit in the Circulation Pump harness connector. The test light should
operate as follows:
With the Residual Engine Heat Utilization (REST) switch off, the test light should
not illuminate.
Press the Residual Engine Heat Utilization (REST) switch on. The test light should
illuminate brightly.
Does the test light function as specified?All
Yes, Light Only Illuminates With REST On
Replace the Circulation Pump in accordance with the Service
Information.
Perform BODY VERIFICATION TEST - VER 1.
No, Light Illuminates With REST Off
Go To 2
No, Light Will Not Illuminate
Go To 3
2 Turn the ignition off.
NOTE: Check connectors - Clean/repair as necessary.
Disconnect the Circulation Pump harness connector.
Disconnect the Automatic Temperature Control (ATC) C1 harness connector.
Turn the ignition on.
Measure the voltage of the Circulation Pump Control circuit.
Is the voltage above 0.2 volts?All
Ye s!Repair the Circulation Pump Control circuit for a short to voltage.
Perform BODY VERIFICATION TEST - VER 1.
No!Replace the Automatic Temperature Control (ATC) in accordance
with the Service Information.
Perform BODY VERIFICATION TEST - VER 1.
152
HEATING & A/C

Symptom:
NO COMMUNICATION BUS (ACTIVE)
When Monitored and Set Condition:
NO COMMUNICATION BUS (ACTIVE)
When Monitored: With the ignition on.
Set Condition: This DTC will set if the Automatic Temperature Control (ATC) fails to
receive all module messages.
POSSIBLE CAUSES
CAN CIRCUITS SHORTED TO VOLTAGE
MODULE SHORT TO VOLTAGE
CAN CIRCUITS SHORTED TO GROUND
MODULE SHORT TO GROUND
CAN CIRCUITS SHORTED TOGETHER
ENGINE CONTROL MODULE
SENTRY KEY REMOTE ENTRY MODULE
TEST ACTION APPLICABILITY
1 Turn the ignition off.
Disconnect the Instrument Cluster harness connectors.
Turn the ignition on.
Measure the voltage between CAN C Bus (+) circuit and ground.
Measure the voltage between CAN C Bus (-) circuit and ground.
Is the voltage above 3.0 volts on either circuit?All
Ye s!Go To 2
No!Go To 3
160
HEATING & A/C

TEST ACTION APPLICABILITY
5 Turn the ignition off.
Disconnect the negative battery cable.
NOTE: Refer to the wiring diagrams in the service information to help
determine which modules are connected to the CAN Bus.
Disconnect all of the modules that are connected to the CAN Bus.
Measure the resistance between the CAN C Bus (+) circuit and the CAN C Bus (-)
circuit at any disconnected module's harness connector.
Is the resistance below 10k ohms?All
Ye s!Repair the CAN C Bus (+) circuit for a short to the CAN C Bus (-)
circuit.
Perform BODY VERIFICATION TEST - VER 1.
No!Go To 6
6 Turn the ignition off.
Reconnect the Engine Control Module harness connectors.
While back probing, measure the resistance of the CAN C Bus (+) circuit and the
CAN C Bus (-) circuit at the ECM harness connector.
Is the resistance 120.0   2.0 ohms?All
Ye s!Replace the Sentry Key Remote Entry Module in accordance with
the Service Information.
Perform BODY VERIFICATION TEST - VER 1.
No!Replace the Engine Control Module in accordance with the
Service Information.
Perform BODY VERIFICATION TEST - VER 1.
162
HEATING & A/C
NO COMMUNICATION BUS (ACTIVE) ÐContinued

Symptom:
NO COMMUNICATION WITH ECM (ACTIVE)
When Monitored and Set Condition:
NO COMMUNICATION WITH ECM (ACTIVE)
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.
POSSIBLE CAUSES
CAN C BUS CIRCUIT(S) SHORTED OR OPEN
ENGINE CONTROL MODULE DTC(S) PRESENT
ENGINE CONTROL MODULE'S POWER/GROUND CIRCUIT(S) SHORTED OR OPEN
ENGINE CONTROL MODULE
CAN C BUS (+)/CAN C BUS (-) CIRCUIT(S) OPEN TO ENGINE CONTROL MODULE
AUTOMATIC TEMPERATURE CONTROL (ATC)
CAN C BUS (+)/CAN C BUS (-) CIRCUIT(S) OPEN TO AUTOMATIC TEMPERATURE CONTROL
TEST ACTION APPLICABILITY
1 Turn the ignition on.
With the DRBIIIt, read Automatic Temperature Control DTCs.
Does the DRBIIItdisplay: NO COMMUNICATION BUS?All
Ye s!Refer to the Communication category for the related symptom.
Perform BODY VERIFICATION TEST - VER 1.
No!Go To 2
2 Turn the ignition on.
With the DRBIIIt, read Engine Control Module DTCs.
Does the DRBIIItdisplay any DTCs?All
Ye s!Refer to Powertrain Diagnostic information for the related symp-
tom(s).
Perform BODY VERIFICATION TEST - VER 1.
No!Go To 3
3 Turn the ignition on.
With the DRBIIIt, check the TCM, IC, and ABS module for the same or similar No
Communication with Engine Control Module DTC.
Does the DRBIIItdisplay same or similar DTC in TCM, IC, & ABS module?All
Ye s!Go To 4
No!Go To 6
163
HEATING & A/C

TEST ACTION APPLICABILITY
4 Turn the ignition off.
Disconnect the Engine Control Module harness connectors.
Check all of the engine control module's power circuits for a short or open condition.
Check all of the engine control module's ground circuits for an open condition.
Were any problems found?All
Ye s!Repair the power/ground circuit(s) as necessary.
Perform BODY VERIFICATION TEST - VER 1.
No!Go To 5
5 Turn the ignition off.
Disconnect the Engine Control Module harness connectors.
Measure the resistance between the CAN C Bus (+) circuit and the CAN C Bus (-)
circuit in the Engine Control Module harness connector.
Is the resistance 57 to 63 ohms?All
Ye s!Replace the Engine Control Module in accordance with the
Service Information.
Perform BODY VERIFICATION TEST - VER 1.
No!Repair the CAN C Bus (+)/CAN C Bus (-) circuit(s) for an open.
Perform BODY VERIFICATION TEST - VER 1.
6 Turn the ignition off.
Disconnect the Automatic Temperature Control (ATC) C1 harness connector.
Measure the resistance between the CAN C Bus (+) circuit and the CAN C Bus (-)
circuit in the Automatic Temperature Control (ATC) C1 harness connector.
Is the resistance 57 to 63 ohms?All
Ye s!Replace the Automatic Temperature Control in accordance with
the Service Information.
Perform BODY VERIFICATION TEST - VER 1.
No!Repair the CAN C Bus (+)/CAN C Bus (-) circuit(s) for an open.
Perform BODY VERIFICATION TEST - VER 1.
164
HEATING & A/C
NO COMMUNICATION WITH ECM (ACTIVE) ÐContinued

Symptom:
REFRIG PRESS SENSOR SHORTED LOW (ACTIVE)
POSSIBLE CAUSES
REFRIGERANT PRESSURE SENSOR
5 VOLT SUPPLY CIRCUIT SHORTED TO GROUND
5 VOLT SUPPLY CIRCUIT SHORTED TO GROUND CIRCUIT
5 VOLT SUPPLY CIRCUIT SHORTED TO SENSOR GROUND CIRCUIT
REFRIGERANT PRESSURE SENSOR FEEDBACK CIRCUIT SHORTED TO GROUND
REFRIGERANT PRESSURE SENSOR FEEDBACK CIRCUIT SHORTED TO GROUND CIRCUIT
REFRIGERANT PRESSURE SENSOR FEEDBACK CIRCUIT SHORTED TO SENSOR GROUND
CIRCUIT
AUTOMATIC TEMPERATURE CONTROL (ATC)
TEST ACTION APPLICABILITY
1 Turn the ignition off.
Disconnect the Refrigerant Pressure Sensor harness connector.
NOTE: 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: REFRIG PRESS SENSOR SHORTED LOW?All
Ye s!Go To 2
No!Replace the Refrigerant Pressure Sensor in accordance with the
Service Information.
Perform BODY VERIFICATION TEST - VER 1.
2 Turn the ignition off.
Disconnect the Automatic Temperature Control (ATC) C1 harness connector.
Measure the resistance between ground and the 5 Volt Supply circuit.
Is the resistance below 10k ohms?All
Ye s!Repair the 5 Volt Supply circuit for a short to ground.
Perform BODY VERIFICATION TEST - VER 1.
No!Go To 3
173
HEATING & A/C

Symptom:
WATER CYCLE VALVE CONTROL HIGH OR OPEN (ACTIVE)
POSSIBLE CAUSES
WATER CYCLE VALVE
WATER CYCLE VALVE CONTROL CIRCUIT SHORTED TO VOLTAGE
AUTOMATIC TEMPERATURE CONTROL (ATC)
WATER CYCLE VALVE CONTROL CIRCUIT OPEN
GROUND CIRCUIT OPEN
AUTOMATIC TEMPERATURE CONTROL (ATC)
TEST ACTION APPLICABILITY
1 Turn the ignition off.
Press the Residual Engine Heat Utilization (REST) switch off.
NOTE: Check connectors - Clean/repair as necessary.
Disconnect the Water Cycle Valve harness connector.
Connect a 12-volt test light between the Water Cycle Valve Control circuit and the
Ground circuit in the Water Cycle Valve harness connector. The test light should
operate as follows:
With the Residual Engine Heat Utilization (REST) switch off, the test light should
not illuminate.
Press the Residual Engine Heat Utilization (REST) switch on.
With the Blend control set to Full Cold, the test light should illuminate brightly and
continuously.
With the Blend control set to one position below the half Cold/Hot setting, the test
light should illuminate brightly and blink at a slow continuous rate.
With the Blend control set to the half Cold/Hot setting or above, the test light should
be off.
Does the test light operate as specified?All
Ye s!Replace the Water Cycle Valve in accordance with the Service
Information.
Perform BODY VERIFICATION TEST - VER 1.
No, Light Illuminates With REST Off.
Go To 2
No, Light Will Not Illuminate
Go To 3
No, Light Won't Correspond To Blend
Go To 3
175
HEATING & A/C