1997 MERCEDES-BENZ ML320 overheating

195 Operation
Driving instructions
Install only brake pads and brake fluid
recommended by Mercedes-Benz.
After hard braking, it is advisable to drive
on for some time, rather than immediately
parking, so the air stream will cool down
the brakes faster.
Driving off
Apply the brakes to test them briefly after
driving off. Perform this procedure only
when the road is clear of other traffic.
Warm up the engine smoothly. Do not
place full load on the engine until the oper-
ating temperature has been reached.
When starting off on a slippery surface, do
not allow a drive wheel to spin for an ex-
tended period with the ESP switched off.
Doing so may cause serious damage to the
drivetrain which is not covered by the
Mercedes-Benz Limited Warranty.
Warning!
G
If other than recommended brake pads are
installed, or other than recommended brake
fluid is used, the braking properties of the
vehicle can be degraded to an extent that
safe braking is substantially impaired. This
could result in an accident.
!When driving down long and steep
grades, relieve the load on the brakes
by shifting into a lower gear to use the
engine’s braking power. This helps
prevent overheating of the brakes and
reduces brake pad wear.

210 OperationDriving instructions

The vehicle and trailer combination is
heavier, and therefore is limited in ac-
celeration and climbing ability, and re-
quires longer stopping distances.
I t i s m o r e p r o n e t o r e a c t i n g t o s i d e w i n d
gusts, and requires more sensitive
steering input.


If possible, do not brake abruptly, but
rather engage the brake slightly at first
to permit the trailer to activate its
brake. Then increase the braking force.


If the transmission hunts between
gears on inclines, manually shift to a
lower gear (select 4, 3, 2 or 1).
A lower gear and reduction of speed re-
duces the chance of engine overload-
ing and / or overheating.


On very steep inclines, not manageable
with gear selector lever in position1,
switch transfer case to LOW RANGE
mode (
page 125).


When going down a long hill, shift into
a lower gear and use the engine’s brak-
ing effect.
Avoid riding the brakes, thus overheat-
ing the vehicle and trailer brakes.


If the engine coolant rises to an ex-
tremely high temperature (coolant tem-
perature needle approaching the red
zone) when the air conditioning is on,
turn off the air conditioning system.
Engine coolant heat can be additionally
vented by opening the windows,
switching the climate control fan speed
to high and setting the temperature
control to the maximum hot position.


Extreme care must be exercised since
your vehicle with a trailer will require
additional passing distance ahead than
when driving without a trailer.
Because your vehicle and trailer is
longer than your vehicle alone, you will
also need to go much farther ahead of
the passed vehicle before you can re-
turn to your lane.
!If the trailer should begin to sway, re-
duce the vehicle’s speed and use the
brake controller by hand to straighten
out the vehicle and trailer.
In no case should you attempt to
straighten out the tow vehicle and trail-
er by increasing the speed or overstee-
ring and stepping on the brakes.

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.

location/design/function113, 119, 137
Engine 120GF30.20-P-3010F
Anti-knock control function GF15.12-P-4024F
Transmission overload protection
functionwith automatic
transmissionGF07.61-P-4026F
Overheating/pinging protection
function GF07.61-P-4027F
Intake air temperature correction
function GF07.61-P-4028F
ME-SFI synchronizing fuel
injection and firing order function GF07.61-P-4009F
ME-SFI ignition system signal
assignmentEngine 104GF15.12-P-0001-02D
Engine 111GF15.12-P-0001-02G
Engine 112GF15.12-P-0001-02A
Engine 113GF15.12-P-0001-02B
Engine 119GF15.12-P-0001-02E
Engine 120GF15.12-P-0001-02F
Engine 137GF15.12-P-0001-02L
ME engine speed signal function GF07.61-P-3017F
ASR V control unit
location/task/design/functionwith code 471a
Model 129, 140, 202 as
of 6/94, 170, 208, 210GF42.40-P-4500A
ESP control unit location / task /
functionwith code 472a
Model 129 with engines
104, 119, 120
Model 140
Model 210 with engine
119GF42.45-P-4500A
with code 472a
Model 129 with engine
112, 113
Model 163 up to 8/02,
168, 215
Model 220 (except
220.08/18)
Model 202, 208 with
engine 112, 113
Model 210 with engine
111, 112, 113GF42.45-P-4500B
with code 472a
Model 170 with engines
111, 112
Model 202, 208 with
Engine 111
Model 203GF42.45-P-4500C

2001 Mercedes-Benz ML320
1998-2005 ENGINE Electrical System - Engine - 163 Chassis
me
Saturday, October 02, 2010 3:18:54 PMPage 20 © 2006 Mitchell Repair Information Company, LLC.

ASSESSMENT OF DAMAGE IN WIRING HARNESSES - AH00.19-P-1000-05A
Model 124, 126, 129, 140, 163, 164, 168, 169, 170, 171, 199, 202, 203, 208, 209, 210, 211, 215, 216, 219, 220,
221, 230, 240, 245, 251, 414, 461, 463
Always assess the damage thoroughly before repairing the wiring harnesses.
The following criteria must be observed:
Type of damage:
Damage caused by scorching/overheating, chafing, clamping, crushing, severing, fatigue, corrosion, cable
chewed by an animal, assembly fault.
Cause of damage:
Equipment and
tools required Side cutting pliers
Wire stripper
Crimper with
special die setsSide cutting pliers
Wire stripper
Hot air blower with
special reflector
Raychem connection
Cable tails
Heat shield matSide cutting pliers
Wire stripper
Soldering iron with
accessories
Heat shield mat as
drip protectionSide cutting pliers
Water-pump pliers
Type of contact clampedsolderedsolderedclamped
Heat source NoneHot air gun with
special reflector
(400°C)Soldering iron
(400°C)None
Advantages Quick repair, no
mains power
connection required
Strain relieved by
clamping the
insulation
Simple visual
inspection of
connectionInsulation occurs
automatically
Sealing occurs
automatically
Avoids taut wires by
introducing additional
wiresReplace soldered
contacts (special
applications)No wire stripping
or cutting required
Relatively short
set-up time
No special tool
required
Disadvantages Special crimping
components
requiredMains power
connection required
Accessibility for hot
air gun must be
ensured
Measures for heat
protection requiredExtensive
preparation and
post-working
requiredNo watertight
versions, therefore
only suitable for
use inside the
vehicle or in the
trunk area
Use limited to
certain cable cross-
sections
Not permissible for
CAN lines

2004 Mercedes-Benz ML350
1998-2005 GENINFO Overall vehicle - 163 Chassis
me
Saturday, October 02, 2010 3:47:44 PMPage 20 © 2006 Mitchell Repair Information Company, LLC.

The cause for the damage must be determined to ensure that the damage does not reoccur after the wiring
harness has been repaired.
Scope of the damage:
Which components are damaged, can the damage be identified exactly?
Can you be sure that no other components are damaged?
Repair options:
What are the options for repair?
Which replacement parts are available?
Overview of causes for damage to wiring harnesses
Type of damage:Possible causes for damagePossible scope of damage
Scorching/ overheating Through external
overheating:
Through contact with hot
components (e.g. exhaust
system), during welding and
soldering, painting and
drying work
Fire
Internal overheating because
electric currents are too high:
Short circuits at defective
components or lines, cable
cross-section too small,
incorrect fusing (parts not
installed correctly or repairs
not carried out correctly),
short circuits due to bridging
(e.g. at wire ends that are not
insulated, if insulation is
damaged)
Insulation and wires
damaged
Connector housing deformed
Open circuit in wiring
Insulated hard and cracked
Chafing, clamping, crushing,
severing Lines routed or secured
incorrectly
Damage as a result of an
accident
Damage to cable when
boring holes or when
screwing sheet metal screws
Insulation and wires
damaged
Lines or connections to
contacts
High line resistance
Short circuit to ground and
power

2004 Mercedes-Benz ML350
1998-2005 GENINFO Overall vehicle - 163 Chassis
me
Saturday, October 02, 2010 3:47:44 PMPage 21 © 2006 Mitchell Repair Information Company, LLC.

natural gas powered
vehicles. Risk of frostbite to
body parts caused by
escaping natural gas or
contact with components
near the valves when
draining compressed-gas
tanks. Risk of poisoning or
suffocation caused by
inhaling natural gas. 6/07
G/02/07. This WIS printout
will not be recorded by the
updateservice.
Risk of explosion caused by
liquefied petroleum gas
escaping or pressurized gas
reservoirs overheating when
working on vehicles
operated with liquefied
petroleum gas. Risk of
frostbite to body parts
caused by liquefied
petroleum gas exiting under
pressure. Risk of poisoning
or risk of suffocation caused
by inhaling liquefied
petroleum gas.ENGINE 111.984 For
Fluid Gas ConcernAS00.00-Z-0023-01A
Risk of injury caused by
burns to skin and eyes. Risk
of poisoning caused by
inhaling fumes when
working with heat-
shrinkable tubing.MODEL 124, 126, 129,
140, 163, 164, 168, 169,
170, 171, 199, 202, 203,
204, 208, 209, 210, 211,
215, 216, 219, 220, 221,
230, 240, 245, 251, 374,
375, 414, 450, 454, 461,
463, 638, 690, 901, 902,
903, 904, 905, 930, 932,
933, 934, 940, 942, 943,
944, 950, 952, 953, 954,
957, 958, 970, 972, 974,
975, 976 ...AS00.19-Z-0001-01A
Risk of injury caused by
burns to skin and eyes, risk
of poisoning caused by
inhaling fumes during
soldering.MODEL 124, 126, 129,
140, 163, 164, 168, 169,
170, 171, 199, 202, 203,
208, 209, 210, 211, 215,
216, 219, 220, 221, 230,
240, 245, 251, 414, 461,
463...AS00.19-Z-0002-01A

2004 Mercedes-Benz ML350
1998-2005 GENINFO Overall vehicle - 163 Chassis
me
Saturday, October 02, 2010 3:47:48 PMPage 234 © 2006 Mitchell Repair Information Company, LLC.

Risk of injury
When working with heat-shrinkable tubing, excessive temperatures may cause burns to skin and eye.
Risk of poisoning
When working with heat-shrinkable tubing, vapors may be produced which lead to symptoms of poisoning such
as coughing, headaches, dizziness and nausea. Moreover, irritation may occur to the respiratory paths and eyes.
Safety precautions/instructions
Work only in well ventilated rooms.
Avoid overheating the heat-shrinkable tubing.
Stop heat-shrinking immediately if the shrink hose becomes blistered or charred or shows other signs of
damage.
Do not inhale the vapors.
Avoid contact with melted shrink tubing.
Wear safety glasses with side protection and protective gloves.
First aid measures
When eyes or skin come in contact with melted shrink tubing
Flush the affected area immediately with plenty of water for approx. 15 minutes.
Treat affected areas like burn wounds. Do not remove any burned parts.
Contact physician or medical service.
When vapor is inhaled:
Take victim to fresh air.
Keep victim calm and cover with a blanket.
Contact physician or medical service.
Fire protection measures
Suitable extinguishing agents
Water mist, general-purpose foam, powder, carbon dioxide
Protective equipment for firefighters (compressed air equipment, oxygen apparatus, chemical resistant
protective clothing)
RISK OF INJURY & RISK OF POISONING - AS00.19-Z-0002-01A
Wear protective gloves, protective clothing and safety glasses. Ensure that the work area is adequately

2004 Mercedes-Benz ML350
1998-2005 GENINFO Overall vehicle - 163 Chassis
me
Saturday, October 02, 2010 3:47:48 PMPage 236 © 2006 Mitchell Repair Information Company, LLC.