1997 MERCEDES-BENZ ML350 check engine

248 Practical hintsWhat to do if …Problem
Possible cause
Suggested solution
?
The yellow “CHECK ENGINE”
malfunction indicator lamp
comes on while driving.
There is a malfunction of:

The fuel management system


The ignition system


The emission control system


Systems which affect emissions
Such malfunctions may result in excessive
emissions values and may switch the engine
to its limp-home (emergency operation)
mode.

Have the vehicle checked as soon as
possible by an authorized
Mercedes-Benz Light Truck Center.
An on-board diagnostic connector is
used by the service station to link the
vehicle to the shop diagnostics sys-
tem. It allows the accurate identifica-
tion of system malfunctions through
the readout of diagnostic trouble
codes. It is located in the front left
area of the footwell next to the park-
ing brake pedal.
The fuel cap is not closed tightly.
Check the fuel cap (
page 214).
Your fuel tank is empty.

After refuelling start the engine three
or four times in succession.
The limp-home mode is canceled. You do
not need to have your vehicle checked.

249 Practical hints
What to do if …
Problem
Possible cause
Suggested solution
/
The yellow coolant warning lamp
comes on when the engine is
running.
The coolant is to hot.
The coolant level is too low.

Stop as soon as possible and allow
the engine and coolant to cool down.

Check the coolant level and add
coolant if necessary (
page 222).
If the warning lamp comes on frequently,
there is a leak in the cooling system.

Have the cooling system checked by
an authorized Mercedes-Benz Light
Truck Center.
The coolant temperature gauge is above
248 °F (120 °C).
The coolant level is too low.

Stop as soon as possible and allow
the engine and coolant to cool down.

Add coolant to prevent engine from
overheating (
page 222).
If the coolant level is correct, the electrical
radiator fan may be broken.

If the coolant temperature is below
the red zone, drive on to the nearest
authorized Mercedes-Benz Light
Truck Center.
Avoid high engine loads (e.g. driving
uphill) and stop-and-go driving.

252 Practical hintsWhat to do if …Problem
Possible cause
Suggested solution
{
The yellow ETS malfunction indi-
cator lamp comes on while driv-
ing.
4-ETS has switched off to prevent overheat-
ing of the brakes. Also see 4-ETS / ESP warn-
ing lamp (
page 251).
As soon as the brakes have cooled off,
4-ETS switches on again.
The indicator lamp goes out.
4-ETS is malfunctioning and has switched off.

Have the 4-ETS checked at an autho-
rized Mercedes-Benz Light Truck Cen-
ter as soon as possible.
ê
The yellow LOW RANGE indicator
lamp flashes after one or more
switching conditions.
The gear selection conditions have not been
adhered to.

Repeat the gear selection process
(page 125).
ê
The yellow LOW RANGE indicator
lamp flashes after switching the
ignition on.
LOW RANGE mode is malfunctioning.
Have the LOW RANGE mode checked at
an authorized Mercedes-Benz Light Truck
Center.
The yellow fuel tank reserve
warning lamp comes on while
driving.
The fuel level has gone below the reserve
mark.

Refuel at the next gas station
(page 214).
The yellow fuel tank reserve
warning lamp flashes when leav-
ing the engine running.
The fuel cap is not closed tightly.

Check the fuel cap (
page 214).

254 Practical hintsWhat to do if …Problem
Possible cause
Suggested solution
#
The red charge indicator lamp
comes on when the engine is
running.
The battery is no longer charging.
Possible causes:

alternator malfunctioning


broken poly-V-belt

Stop immediately and check the
poly-V-belt.
If it is broken

Do not continue to drive, before the
poly-V-belt is replaced.
Notify an authorized Mercedes-Benz
Light Truck Center.
2
The yellow brake indicator lamp
comes on during braking or after
starting the engine.
The brake pads are worn down.

Have the system checked at an autho-
rized Mercedes-Benz Light Truck
Center.
!Brake pad thickness must be visually
checked by a qualified technician at the
intervals specified in the Service book-
let.

278 Practical hintsBattery
BatteryThe battery is located on the passenger
side of the engine compartment.
1Negative terminal
2Positive terminal
Warning!
G
Failure to follow these instructions can re-
sult in severe injury or death.
Observe all safety instructions and precau-
tions when handling automotive batteries
(page 223).
Never lean over batteries while connecting,
you might get injured.
Battery fluid contains sulfuric acid. Do not
allow this fluid to come in contact with eyes,
skin or clothing. In case it does, immediately
flush affected area with water and seek
medical help if necessary.
A battery will also produce hydrogen gas,
which is flammable and explosive. Keep
flames or sparks away from battery, avoid
improper connection of jumper cables,
smoking etc.
!Never loosen or detach battery termi-
nal clamps while the engine is running
or the key is in the steering lock. Other-
wise the alternator and other electronic
components could be severely dam-
aged.
Have the battery checked regularly by
an authorized Mercedes-Benz Light
Truck Center.
Refer to Service Booklet for mainte-
nance intervals or contact your autho-
rized Mercedes-Benz Light Truck
Center for further information.Warning!
G
Do not place metal objects on the battery as
this could result in a short circuit.
Use leak-proof battery only to avoid the risk
of acid burns in the event of an accident.

281 Practical hints
Jump starting
Jump starting
If the battery is discharged, the engine can
be started with jumper cables and the bat-
tery of another vehicle. Observe the follow-
ing:

Jump starting should only be performed
when the engine and catalytic convert-
er are cold.


Do not start the engine if the battery is
frozen. Let the battery thaw out first.


Only jump start from batteries with the
same voltage rating (12 V). Jump start-
ing with a more powerful battery could
damage the vehicle's electrical system,
which will not be covered by the
Mercedes-Benz Limited Warranty.


Use only jumper cables with sufficient-
cross-section and insulated terminal
clamps.


Always make sure the jumper cables
are not on or near pulleys, fans or other
parts that move when the engine is
started or running.
Warning!
G
Failure to follow these directions will cause
damage to the electronic components, and
can lead to a battery explosion and severe
injury or death.
Never lean over batteries while connecting
or jump starting, you might get injured.
Battery fluid contains sulfuric acid. Do not
allow this fluid to come in contact with eyes,
skin or clothing. In case it does, immediately
flush affected area with water, and seek
medical help if necessary.
A battery will also produce hydrogen gas,
which is flammable and very explosive. Keep
flames or sparks away from battery, avoid
improper connection of jumper cables,
smoking, etc.
Attempting to jump start a frozen battery
can result in it exploding, causing personal
injury.
Read all instructions before proceeding.
!Avoid repeated and lengthy starting at-
tempts.
Do not attempt to start the engine us-
ing a battery quick charge unit.
If engine does not run after several un-
successful starting attempts, have it
checked at the nearest authorized
Mercedes-Benz Light Truck Center.
Excessive unburned fuel generated by
repeated failed starting attempts may
damage the catalytic converter and
may present a fire risk.
Make sure the jumper cables do not
have loose or missing insulation.
Make sure the cable clamps do not
touch any other metal part while the
other end is still attached to a battery.

282 Practical hintsJump startingThe battery is located on the right side of
the engine compartment.
Make sure the two vehicles do not
touch.

Turn off all electrical consumers.

Apply parking brake.

Shift gear selector lever to positionP.

Open the hood.

Connect positive terminals1 and4
of the batteries with the jumper cable.
Clamp cable to positive terminal4 of
charged battery first.1Positive terminal of discharged battery
2Negative terminal of discharged
battery
3Negative terminal of charged battery
4Positive terminal of charged battery

Start engine of the vehicle with the
charged battery and run at idle speed.

Connect negative terminals2 and3
of the batteries with the jumper cable.
Clamp cable to negative terminal3 of
charged battery first.

Start the engine of the disabled vehi-
cle.
Now you can turn on the electrical
consumers. Do not turn on the lights under
any circumstances.

Remove the jumper cables first from
the negative terminals2 and3 and
then from positive terminals1
and4.
You can now turn on the lights.

Have the battery checked at the
nearest authorized Mercedes-Benz
Light Truck Center.
Warning!
G
Keep flames or sparks away from battery.
Do not smoke.
Observe all safety instructions and precau-
tions when handling automotive batteries
(page 223).
!Never invert the terminal connections.
!Do not tow-start the vehicle.

302 Technical dataFuels, coolants, lubricants etc.Engine oils
Engine oils are specifically tested for their
suitability in our engines. Therefore, use
only engine oils approved by
Mercedes-Benz. Information on approved
engine oils is available in the Factory
Approved Service Products pamphlet, or at
your authorized Mercedes-Benz Light
Truck Center.
Engine oil additives
Do not blend oil additives with engine oil.
They may damage the engine.
Damage or malfunctions resulting from
blending oil additives are not covered by
the Mercedes-Benz Limited Warranty.Air conditioning refrigerant
R-134a (HFC) refrigerant and special PAG
lubricating oil is used in the air condition-
ing system.
Never use R-12 (CFC) or mineral-based lu-
bricating oil. Otherwise damage to the
system will occur.
Brake fluid
During vehicle operation, the boiling point
of the brake fluid is continuously reduced
through the absorption of moisture from
the atmosphere. Under extremely strenu-
ous operating conditions, this moisture
content can lead to the formation of bub-
bles in the system, thus reducing the sys-
tem’s efficiency.
Therefore, the brake fluid must be re-
placed every two years, preferably in the
spring.
Only brake fluid approved by
Mercedes-Benz is recommended. Your au-
thorized Mercedes-Benz Light Truck
Center will provide you with additional in-
formation.
!Always check the oil filler cap
(page 221) for important information
pertaining to the engine oil needing to
meet a specific Mercedes-Benz specifi-
cation (e.g. MB 229.5). If such informa-
tion is printed on the oil filler cap, only
use an engine oil from the list of ap-
proved engine oils in the Factory Ap-
proved Service Products pamphlet that
meets the specification indicated on
the oil filler cap.
Using engine oils of other specification
may cause the FSS to incorrectly deter-
mine the next service interval and will
result in engine damage not covered by
the Mercedes-Benz Limited Warranty.