2006 MERCEDES-BENZ SPRINTER Fuel

Symptom:
P2351-ECM SUPPLY VOLTAGE TOO LOW
POSSIBLE CAUSES
ECM
ECM IGNITION CIRCUIT OPEN
STARTER OR LIFT PUMP RELAY CIRCUIT(S) SHORTED TO GROUND
INTERMITTENT CONDITION
TEST ACTION APPLICABILITY
1NOTE: If the ECM detects and stores a DTC, the ECM also stores the
engine/vehicle operating conditions under which the DTC was set. Some of
these conditions are displayed on the DRB at the same time the DTC is
displayed.
NOTE: Before erasing stored DTCs, record these conditions. Attempting to
duplicate these conditions may assist when checking for an active DTC.
Turn the ignition on.
With the DRB, erase ECM DTCs.
Turn the ignition off for 10 seconds.
Test drive the vehicle.
Monitor the DRB for ECM DTCs.
Did this DTC set again?All
Ye s!Go To 2
No!Go To 4
2 Turn the ignition off.
Disconnect the ECM harness connectors.
Remove the Starter Relay and disconnect the Fuel Lift Pump harness connector
Measure the resistance between ground and the Starter Relay control circuit.
Measure the resistance between ground and the Fuel Lift Pump Relay control circuit.
Did both circuits measure above 1000 ohms?All
Ye s!Go To 3
No!Repair the relay control circuit(s) that did not measure above
1000 ohms for a short to ground.
Perform ROAD TEST VERIFICATION - VER-2.
3 Turn the ignition off.
Disconnect the ECM harness connectors.
Using the Service Wiring Information determine which circuits in the ECM harness
connector provide Ignition Switch power to the ECM.
Turn the ignition on.
Using a 12-volt test light connected to ground, check each Ignition Switch Output
circuits in the ECM harness connectors.
Does the test light illuminate brightly for each circuit?All
Ye s!Replace the ECM in accordance with the Service Information.
Perform ROAD TEST VERIFICATION - VER-2.
No!Repair the Ignition Supply circuit as necessary.
Perform ROAD TEST VERIFICATION - VER-2.
214
DRIVEABILITY - DIESEL

Symptom List:
P2531-FUEL INJECTOR 1 READ TOO LARGE
P2531-FUEL INJECTOR 1 READ TOO LARGE
P2531-FUEL INJECTOR 1 READ TOO SMALL
P2531-FUEL INJECTOR 1 READ TOO SMALL
P2532-FUEL INJECTOR 2 READ TOO LARGE
P2532-FUEL INJECTOR 2 READ TOO LARGE
P2532-FUEL INJECTOR 2 READ TOO SMALL
P2532-FUEL INJECTOR 2 READ TOO SMALL
P2533-FUEL INJECTOR 3 READ TOO LARGE
P2533-FUEL INJECTOR 3 READ TOO LARGE
P2533-FUEL INJECTOR 3 READ TOO SMALL
P2533-FUEL INJECTOR 3 READ TOO SMALL
P2534-FUEL INJECTOR 4 READ TOO LARGE
P2534-FUEL INJECTOR 4 READ TOO LARGE
P2534-FUEL INJECTOR 4 READ TOO SMALL
P2534-FUEL INJECTOR 4 READ TOO SMALL
P2535-FUEL INJECTOR 5 READ TOO LARGE
P2535-FUEL INJECTOR 5 READ TOO LARGE
P2535-FUEL INJECTOR 5 READ TOO SMALL
P2535-FUEL INJECTOR 5 READ TOO SMALL
Test Note: All symptoms listed above are diagnosed using the same tests.
The title for the tests will be P2531-FUEL INJECTOR 1 READ
TOO LARGE.
POSSIBLE CAUSES
FUEL INJECTOR
INTERMITTENT CONDITION
227
DRIVEABILITY - DIESEL

TEST ACTION APPLICABILITY
1NOTE: If the ECM detects and stores a DTC, the ECM also stores the
engine/vehicle operating conditions under which the DTC was set. Some of
these conditions are displayed on the DRB at the same time the DTC is
displayed.
NOTE: Before erasing stored DTCs, record these conditions. Attempting to
duplicate these conditions may assist when checking for an active DTC.
NOTE: This DTC indicates an internal ECM problem except in the case of
DTC P0606 where it may indicate a fuel injector problem. Using the Service
Information, check the fuel injectors for leakage before replacing the ECM.
Turn the ignition on.
With the DRBIIIt, erase ECM DTCs.
Perform several engine run cycles, turning the ignition off for at least 20 seconds
between each engine run cycle.
With the DRBIIIt, read the ECM DTCs.
Did this DTC set again?All
Ye s!Replace the Fuel Injector identified in the DTC in accordance
with the Service Information.
Perform ROAD TEST VERIFICATION - VER-2.
No!Go To 2
2WARNING: WHEN THE ENGINE IS OPERATING, DO NOT STAND IN A
DIRECT LINE WITH THE FAN. DO NOT PUT YOUR HANDS NEAR THE
PULLEYS, BELTS OR FAN. DO NOT WEAR LOOSE CLOTHING.
NOTE: The conditions that set the DTC are not present at this time. The
following list may help in identifying the intermittent condition.
With the engine running at normal operating temperature, monitor the DRB
parameters related to the DTC while wiggling the wiring harness. Look for param-
eter values to change and/or a DTC to set.
Review the DTC When Monitored and Set Conditions. If possible, try to duplicate the
conditions under which the DTC was set.
Refer to any Technical Service Bulletins (TSB) that may apply.
Visually inspect the related wiring harness. Look for any chafed, pierced, pinched, or
partially broken wires.
Visually inspect the related wiring harness connectors. Look for broken, bent, pushed
out, or corroded terminals.
Were any of the above conditions present?All
Ye s!Repair as necessary.
Perform ROAD TEST VERIFICATION - VER-2.
No!Test Complete.
228
DRIVEABILITY - DIESEL
P2531-FUEL INJECTOR 1 READ TOO LARGE ÐContinued

Symptom:
*CHECKING THE FUEL PRESSURE SENSOR CIRCUITS
POSSIBLE CAUSES
OPEN CIRCUITS
TEST ACTION APPLICABILITY
1 Turn the ignition off.
Disconnect the Fuel Pressure Sensor harness connector.
Disconnect the ECM harness connectors.
Visually inspect the related wiring harness. Look for any chafed, pierced, pinched, or
partially broken wires. Repair as necessary.
Visually inspect the related wiring harness connectors. Look for broken, bent, pushed
out, or corroded terminals. Repair as necessary.
Measure the resistance of each of the three Fuel Pressure Sensor circuits between the
ECM harness connector and the Fuel Pressure Sensor harness connector.
Is the resistance below 10.0 ohms for each measurement?All
Ye s!Test Complete.
No!Repair open circuit(s) as necessary.
Perform ROAD TEST VERIFICATION - VER-2.
232
DRIVEABILITY - DIESEL

Symptom:
*CHECKING THE FUEL PRESSURE SOLENOID CIRCUITS
POSSIBLE CAUSES
FUEL PRESSURE SOLENOID RESISTANCE
OPEN CIRCUITS
TEST ACTION APPLICABILITY
1 Turn the ignition off.
Disconnect the Fuel Pressure Solenoid harness connector.
Disconnect the ECM harness connectors.
Visually inspect the related wiring harness. Look for any chafed, pierced, pinched, or
partially broken wires. Repair as necessary.
Visually inspect the related wiring harness connectors. Look for broken, bent, pushed
out, or corroded terminals. Repair as necessary.
Measure the resistance of both Fuel Pressure Solenoid circuits between the ECM
harness connector and the Fuel Pressure Solenoid harness connector.
Is the resistance below 10.0 ohms for both measurements?All
Ye s!Go To 2
No!Repair open circuit(s) as necessary.
Perform ROAD TEST VERIFICATION - VER-2.
2 Turn the ignition off.
Disconnect the Fuel Pressure Solenoid harness connector.
Measure the resistance of the Fuel Pressure Solenoid.
Is the resistance between 3.5 and 5.5 ohms?All
Ye s!Test Complete.
No!Replace the Fuel Pressure Solenoid.
Perform ROAD TEST VERIFICATION - VER-2.
233
DRIVEABILITY - DIESEL

Symptom:
*CHECKING THE FUEL QUANTITY SOLENOID CIRCUITS
POSSIBLE CAUSES
OPEN CIRCUITS
TEST ACTION APPLICABILITY
1 Turn the ignition off.
Disconnect the Fuel Quantity Solenoid harness connector.
Disconnect the ECM harness connectors.
Visually inspect the related wiring harness. Look for any chafed, pierced, pinched, or
partially broken wires. Repair as necessary.
Visually inspect the related wiring harness connectors. Look for broken, bent, pushed
out, or corroded terminals. Repair as necessary.
Measure the resistance of both Fuel Quantity Solenoid circuits between the ECM
harness connector and the Fuel Quantity Solenoid harness connector.
Is the resistance below 10.0 ohms for both measurements?All
Ye s!Test Complete.
No!Repair open circuit(s) as necessary.
Perform ROAD TEST VERIFICATION - VER-2.
234
DRIVEABILITY - DIESEL

TEST ACTION APPLICABILITY
8 Turn the ignition off.
Remove and inspect Fuse #16 from Fuse Block No.1
Is the fuse open?All
Ye s!Go To 9
No!Go To 11
9 Turn the ignition off.
Disconnect the ECM harness connectors.
Install a good fuse in place of Fuse #16 in Fuse Block No.1
Connect a jumper wire between ground and the Engine Control Relay Control circuit
in ECM C2 harness connector cavity 44.
Remove and inspect Fuse #16 from Fuse Block No.1.
Is the fuse open?All
Ye s!Repair the Engine Control Relay Output circuit for a short to
ground.
Perform ROAD TEST VERIFICATION - VER-2.
No!Go To 10
10 The Fuel Injectors, Crankcase Heater, Water In Fuel Sensor and related circuits can
cause Fuse #16 in Fuse Block No.1 to open. Use the Service Information Wiring
Diagrams and check these circuits/components for shorted circuits.
Were any problems found.All
Ye s!Repair or replace shorted circuit/component as necessary.
Perform ROAD TEST VERIFICATION - VER-2.
No!Replace and program the ECM in accordance with the Service
Information.
Perform ROAD TEST VERIFICATION - VER-2.
11 Turn the ignition off.
Disconnect the ECM harness connectors.
Connect a jumper wire between ground and the Engine Control Relay Control circuit
in ECM C2 harness connector cavity 44.
Turn the ignition on.
Using a 12-volt test light connected to ground, check the Fused Engine Control Relay
Output circuits at the ECM C2 harness connector cavities 1, 3 and 5.
Choose the appropriate result.All
Test light is on for all circuits.
Test Complete.
Test light is on for 1 or 2 circuits
Repair the Engine Control Relay Output circuit(s) for an open.
Perform ROAD TEST VERIFICATION - VER-2.
Light off for all circuits.
Go To 12
237
DRIVEABILITY - DIESEL
*CHECKING THE POWER AND GROUNDS ÐContinued

Symptom:
*ENGINE CRANKS BUT WILL NOT START
POSSIBLE CAUSES
CAMSHAFT POSITION SENSOR SIGNAL PROBLEM
CRANKSHAFT POSITION SENSOR SIGNAL PROBLEM
ECM CODES PRESENT
ECT SENSOR
ENGINE CONTROL MODULE
ENGINE DRIVE GEAR/SPROCKET
FUEL SUPPLY CONTAMINATION
FUEL SYSTEM PRESSURE MECHANICAL
FUEL SYSTEM RESTRICTION
GLOW PLUGS
SKIM CODES PRESENT
TEST ACTION APPLICABILITY
1NOTE: The ECM must have proper power and ground connections for the
following tests to be valid. Refer to Checking the ECM Power and Grounds
in the symptom list.
NOTE: A no-start condition may occur if the Fuel Temperature Sensor is
shorted or if the Fuel Temperature Sensor Signal circuit is shorted to
ground or shorted to Sensor Ground.
Turn the ignition on.
With the DRBIIIt, read the ECM DTCs.
Does the DRBIIItdisplay any ECM DTCs?All
Ye s!Refer to symptom list for problems related to ECM DTC.
Perform NO START VERIFICATION - VER-1.
No!Go To 2
2 Turn the ignition on.
With the DRBIIIt, read the SKREEM DTCs.
Does the DRBIIItdisplay any SKREEM DTCs?All
Ye s!Refer to symptom list for problems related to SKIM DTC.
Perform NO START VERIFICATION - VER-1.
No!Go To 3
3 Using a temperature probe, check the vehicle temperature near the ECT Sensor.
Turn the ignition on.
With the DRBIIItin Sensors, read the ECT Sensor temperature.
Compare the temperature probe reading with the DRBIIItreading.
Are the two readings within 10ÉC of each other?All
Ye s!Go To 4
No!Repair as necessary.
Perform NO START VERIFICATION - VER-1.
239
DRIVEABILITY - DIESEL