2006 MERCEDES-BENZ SPRINTER air condition

4.2.4 DRBIIITSAFETY INFORMATION
WARNING: EXCEEDING THE LIMITS OF THE
DRBIIITMULTIMETER IS DANGEROUS. IT
CAN EXPOSE YOU TO SERIOUS OR
POSSIBLE FATAL INJURY. CAREFULLY
READ AND UNDERSTAND THE CAUTIONS
AND THE SPECIFICATION LIMITS.
²Follow the vehicle manufacturer 's service speci-
fications at all times.
²Do not use the DRBIIItif it has been damaged.
²Do not use the test leads if the insulation is
damaged or if metal is exposed.
²To avoid electrical shock, do not touch the test
leads, tips, or the circuit being tested.
²Choose the proper range and function for the
measurement. Do not try voltage or current mea-
surements that may exceed the rated capacity.
²Do not exceed the limits shown in the table below:
FUNCTION INPUT LIMIT
Volts 0 - 500 peak volts AC
0 - 500 volts DC
Ohms (resistance)* 0 - 1.12 megaohms
Frequency Measured
Frequency Generated0-10kHz
Temperature -58 - +1100ÉF
-50 - +600ÉC
* Ohms cannot be measured if voltage is present.
Ohms can be measured only in a non-powered
circuit.
± Voltage between any terminal and ground
must not exceed 500v DC or 500v peak AC.
± Use caution when measuring voltage above
25v DC or 25v AC.
± Use the low current shunt to measure circuits
up to 10A. Use the high current clamp to
measure circuits exceeding 10A.
± When testing for the presence of voltage or
current, make sure the meter is functioning
correctly. Take a reading of a known voltage or
current before accepting a zero reading.
± When measuring current, connect the meter in
series with test load.
± When using the meter function, keep the
DRBIIItaway from spark plug or coil wires to
avoid measuring error from outside interfer-
ence.
4.3 WARNING
4.3.1 VEHICLE DAMAGE WARNINGS
Before disconnecting any control module, make
sure the ignition is ``off ''. Failure to do so could
damage the module.
When testing voltage or continuity at any control
module, use the terminal side (not the wire end) of
the connector. Do not probe a wire through the
insulation; this will damage it and eventually cause
it to fail because of corrosion.
Be careful when performing electrical tests so as
to prevent accidental shorting of terminals. Such
mistakes can damage fuses or components. Also, a
second code could be set, making diagnosis of the
original problem more difficult.
4.3.2 ROAD TESTING A COMPLAINT
VEHICLE
Some complaints will require a test drive as part
of the repair verification procedure. The purpose of
the test drive is to try to duplicate the diagnostic
code or symptom condition.
CAUTION: Before road testing a vehicle, be
sure that all components are reassembled.
During the test drive, do not try to read the
DRBIIITscreen while in motion. Do not hang
the DRBIIITfrom the rear view mirror or
operate it yourself. Have an assistant
available to operate the DRBIIIT.
4.4 DIAGNOSIS
1. Your diagnostic test procedure must begin with a
thorough visual inspection of the system in ques-
tion for damaged components or disconnected
connectors. For ABS, the brake lamps must be
operational prior to continuing.
2. Connect the DRBIIItto the data link connector
located under the dash. If the DRBIIItdoes not
power up, check the power and ground supplies
to the connector.
3. Select the system in question. Turn the ignition
on. If the DRBIIItdisplays ``No Responseº, refer
to Communication in the Body Diagnostic Pro-
cedures manual to diagnose the symptom.
4. Read and record all diagnostic trouble codes. If
any additional codes are present, proceed to the
appropriate test.
5. For ABS, if there are no diagnostic trouble codes
present, select ``Inputs/Outputs'' and read the
Brake Switch and Brake Lamp Switch inputs as
you press and release the brake pedal. If the
6
GENERAL INFORMATION

display does not match the state of the pedal,
perform the proper test. For a problem with the
ªABSº warning indicator, refer to the proper test.
6. If no other problems are found, it will be neces-
sary to road test the vehicle.THE DRBIIIt
MUST NOT BE CONNECTED TO THE
DATA LINK CONNECTOR WHEN ROAD
TESTING FOR PROPER ANTILOCK OP-
ERATION. THE SYSTEM IS DISABLED
WHILE IN DIAGNOSTIC MODE.Perform
several antilock stops from above 50 Km/h (30
mph) and then repeat steps 2, 3, and 4. If any
diagnostic trouble codes are present, proceed to
the appropriate test.
7. The following conditions should be considered
``NORMAL'' operation, and no repairs should be
attempted to correct them.
± Brake pedal feedback during an ABS stop
(clicking, vibrating)
± Clicking, groaning or buzzing at 12 Km/h (8
mph) (drive off self test)
± Groaning noise during an ABS stop
± Slight brake pedal drop and pop noise when
ignition is initially turned on
± Brake pedal ratcheting down at the end of an
ABS stop
8. If the complaint is ABS ``cycling'' at the end of a
stop at low speeds, it may be caused by a
marginal wheel speed sensor signal. The sensor
air gap, tone wheel condition, and/or brakes
hanging up are possible causes of this condition.
9. After a road test in which no problems were
found, refer to any Technical Service Bulletins
that may apply.
5.0 REQUIRED TOOLS AND
EQUIPMENT
DRBIIIt(diagnostic read-out box)
jumper wires
ohmmeter
voltmeter
test light
oscilloscope
6.0 GLOSSARY OF TERMS
ABSantilock brake system
ACalternating current
BCMbody control module
BSbrake switch
BLSbrake lamp switch
CABcontroller antilock brakeDCdirect current
DLCdata link connector
DRBIIItdiagnostic read-out box
DTCdiagnostic test code
EBDelectronic brake distribution
ECMelectronic control module
HCUhydraulic control unit
HZHertz
ICinstrument cluster
LFleft front
LRleft rear
PMpump motor
RFright front
RRright rear
SOLsolenoid
TCStraction control system
TCSStraction control system switch
VSSvehicle speed signal
WSSwheel speed sensor
7
GENERAL INFORMATION

TEST ACTION APPLICABILITY
4 Turn the ignition off.
Disconnect the Brake Pressure Sensor harness connector.
Disconnect the CAB harness connector.
Measure the resistance of the Brake Pressure Sensor signal circuit.
Measure the resistance of the Brake Pressure Sensor ground circuit.
Measure the resistance of the Brake Pressure Sensor 5 volt supply circuit.
Is the resistance above 5.0 ohms for any of the circuits?All
Ye s!Repair the Brake Pressure Sensor circuit(s) for an open
No!Go To 5
5 Turn the ignition off.
Disconnect the Brake Pressure Sensor harness connector.
Inspect the harness and connectors related to this circuit. If any problems are found,
repair as necessary.
If no problems are found, replace the Brake Pressure Sensor in accordance with the
Service Information.
With the DRBIIIt, clear DTCs.
Road test the vehicle and perform several braking maneuvers.
With the DRBIIIt, read DTCs.
Does this DTC reset?All
Ye s!Replace the CAB in accordance with the Service Information.
No!Test Complete.
6 The condition that set this DTC is not present at this time.
Monitor the DRBIIItwhile wiggle testing the related harness and connectors. Look
for any related parameters to change or for the DTC to reset.
Inspect the related harness and connectors.
Look for any chafed, pierced, pinched, or partially broken wires.
Look for broken, bent, pushed out, or corroded terminals.
Were any problems found?All
Ye s!Repair as necessary.
No!Test Complete.
16
BRAKES (CAB)
BRAKE PRESSURE SENSOR CIRCUIT ÐContinued

Symptom:
CAB CHECK SUM
When Monitored and Set Condition:
CAB CHECK SUM
When Monitored: Ignition On - Once
Set Condition: When the sum of all storage bytes are not equal to the original sum stored.
POSSIBLE CAUSES
INTERMITTENT CAB CHECK SUM DTC
DAMAGED CAB/CAB HARNESS CONNECTOR
FUSED OPTIONAL EQUIPMENT RELAY OUTPUT CIRCUIT OPEN
FUSED B(+) CIRCUIT OPEN
GROUND CIRCUIT OPEN
ANTI-LOCK BRAKE CONTROLLER
TEST ACTION APPLICABILITY
1 Turn the ignition on.
With the DRBIIIt, read DTCs.
With the DRBIIIt, erase DTCs.
Turn the ignition off.
Turn the ignition on.
With the DRBIIIt, read DTCs.
Does the DRBIIItdisplay CAB CHECK SUM?All
Ye s!Go To 2
No!Go To 6
2 Turn the ignition off.
Disconnect the CAB harness connector.
Inspect the CAB/CAB harness connector for damage.
Is there any broken, bent, pushed out, corroded or spread terminals?All
Ye s!Repair as necessary.
Perform ABS VERIFICATION TEST - VER 1.
No!Go To 3
21
BRAKES (CAB)

Symptom:
CAB OPTION
When Monitored and Set Condition:
CAB OPTION
When Monitored: Ignition On - Once
Set Condition: When the vehicle line information transmitted does not match the
expected values.
POSSIBLE CAUSES
INTERMITTENT CAB OPTION DTC
DAMAGED CAB/CAB HARNESS CONNECTOR
FUSED OPTIONAL EQUIPMENT RELAY OUTPUT CIRCUIT OPEN
FUSED B(+) CIRCUIT OPEN
GROUND CIRCUIT OPEN
ANTI-LOCK BRAKE CONTROLLER
TEST ACTION APPLICABILITY
1 Turn the ignition on.
With the DRBIIIt, read DTCs.
With the DRBIIIt, erase DTCs.
Turn the ignition off.
Turn the ignition on.
With the DRBIIIt, read DTCs.
Does the DRBIIItdisplay CAB OPTION?All
Ye s!Go To 2
No!Go To 6
2 Turn the ignition off.
Disconnect the CAB harness connector.
Inspect the CAB/CAB harness connector for damage.
Is there any broken, bent, pushed out, corroded or spread terminals?All
Ye s!Repair as necessary.
Perform ABS VERIFICATION TEST - VER 1.
No!Go To 3
23
BRAKES (CAB)

TEST ACTION APPLICABILITY
7 The condition that set this DTC is not present at this time.
Monitor the DRBIIItwhile wiggle testing the related harness and connectors. Look
for any related parameters to change or for the DTC to reset.
Inspect the related harness and connectors.
Look for any chafed, pierced, pinched, or partially broken wires.
Look for broken, bent, pushed out, or corroded terminals.
Were any problems found?All
Ye s!Repair as necessary.
No!Test Complete.
31
BRAKES (CAB)
DRIVE TEST ERROR ÐContinued

TEST ACTION APPLICABILITY
2 Turn the ignition off.
Inspect the tire sizes on the vehicle.
Is a smaller than production tire or spare tire being used?All
Ye s!Repair as necessary.
Perform ABS VERIFICATION TEST - VER 1.
No!Go To 3
3 Turn the ignition off.
Measure all the tire circumferences.
Do all the tire circumferences match?All
Ye s!Go To 4
No!Repair as necessary.
Perform ABS VERIFICATION TEST - VER 1.
4 Turn the ignition off.
Inspect the tone wheel(s) for damage, missing teeth, cracks, or looseness.
NOTE: Refer to the service manual information, if necessary, for procedures
or specifications.
Are one or more tone wheel(s) loose or damaged?All
Ye s!Repair as necessary.
Perform ABS VERIFICATION TEST - VER 1.
No!Go To 5
5 Turn the ignition off.
Inspect the wheel bearings for excessive runout or clearance.
NOTE: Refer to the service information, if necessary, for procedures or
specifications.
Is the wheel bearing clearance within specifications?All
Ye s!Go To 6
No!Repair as necessary.
Perform ABS VERIFICATION TEST - VER 1.
6 Turn the ignition off.
Visually inspect the brakes for locking up due to lining contamination or overheating.
Inspect all brake components for any condition that would cause a variation in wheel
speed.
Is any component damaged?All
Ye s!Repair as necessary.
Perform ABS VERIFICATION TEST - VER 1.
No!Go To 7
7 Turn the ignition on.
With the DRBIIItin Sensors, monitor ALL the Wheel Speed Sensor signals while an
assistant drives the vehicle.
Slowly accelerate from a stop to 65 km/h (40 mph).
NOTE: Wheel Speed should not vary by more than 10% from wheel to wheel
when driving in a straight line.
Do any of the Wheel Speed Sensor signals vary by greater than 10% while driving in
a straight line?All
Ye s!Go To 8
No!Go To 13
33
BRAKES (CAB)
INCORRECT TONE WHEEL ÐContinued

TEST ACTION APPLICABILITY
13 The condition necessary to set this DTC is not present at this time.
Turn the ignition off.
Visually inspect the related wiring harness. Look for any chafed, pierced, pinched, or
partially broken wires.
Visually inspect the related wire harness connectors. Look for broken, bent, pushed
out, or corroded terminals.
Were any problems found?All
Ye s!Repair as necessary.
Perform ABS VERIFICATION TEST - VER 1.
No!Test Complete.
35
BRAKES (CAB)
INCORRECT TONE WHEEL ÐContinued