1997 MERCEDES-BENZ ML320 engine

Fig. 132: Locating In-Car Temperature Sensor With Aspirator Nozzle
1. Check condition of fuses F16, F41, F43, F44.
2. Check aspirator nozzle for in-car temperature sensor as follows: With ignition switched on, place a piece
of paper (arrow) of 1cm surface area on grill in front of in-car temperature sensor with aspirator nozzle
(B10/4). With sufficient ventil ation (aspirator nozzle to blow er), paper remains on grill.
3. Allow engine to idle at operating temperature (engine coolant temperature approx. 80°C) during the
complete duration of the test.
4. Outside temperature > 15°C.
5. Open center and side air outlets manually.
6. Recirculated air switch not pressed.
7. Set blower switch to stage 4.
AIR CONDITIONING (TEMPMATIC ) PRECONDITIONS FOR OPERATIONAL CHECK - AD83.30-P-2000-01GK
as of 1.12.99

2001 Mercedes-Benz ML320
1998-2005 HVAC Climate Control - 163 Chassis
me
Saturday, October 02, 2010 3:23:17 PMPage 163 © 2006 Mitchell Repair Information Company, LLC.

Fig. 133: Locating In-Car Temperature Sensor With Aspirator Blower
1. Check status of fuses F16, F41, F43, F44.
2. Check aspirator blower for in-car temperature sensor: With ignition switched on, place a piece of paper
(arrow) of 1cm surface area on grill in front of in-car temperature sensor (B10/4) with aspirator blower.
With sufficient ventilation (a spirator blower to blower), paper remains on grill.
3. Allow engine to idle for entire duration of test at operating temperature (approx. 80°C coolant
temperature).
4. Outside temperature > 15°C
5. Open center and side nozzles manually.
6. Recirculating air sw itch not pressed.
7. Blower switch on step 1.
Observe run-on time.
AIR CONDITIONING (T EMPMATIC) VERSION CO DING - AD83.30-P-2000-02GH
Variant coding is carried out by the HHT and is menu -assisted. Communication is possible as soon as the
ignition key is inserted in the ignition lock (the igniti on lock position is not important). Variant coding (position
1) is reached from the main menu via control module adaptations (position 5). The following two options are
available in variant coding:
1. Read out coding and transfer to new control module.
2. Readout/change coding.
Position 2 must be selected in order to read out th e air conditioning coding. The air conditioning variant coding
is found under position 07 in the following listing.

2001 Mercedes-Benz ML320
1998-2005 HVAC Climate Control - 163 Chassis
me
Saturday, October 02, 2010 3:23:17 PMPage 164 © 2006 Mitchell Repair Information Company, LLC.

AIR CONDITIONING (TAU) DIAGNOSIS FUNCTION CHECK ACTUAL VALUES - AD83.30-P-3001GH
MODEL 163 with CODE (580) Air conditioning or Tempmatic for USA
5
Recirculated air
mode function switch illuminated
Blower switch on stage 4Blower noise
increases significantly
Cables
Recirculated air
switch
Fresh
air/recirculated air
flap actuator motor
Air conditioning (TAU)
diagnosis previous
knowledge AD83.30-P-2000GH
Connect hand-held tester
(HHT), read out
diagnostic trouble code
memoryModel 163 up to 31.8.01AD00.00-P-2000-03C
Operational check
Test scope Operation /
Requirement Specification Possible cause / Remedy
01
Circuit 30 11-14 VWiring
Battery
02Ignition ON Operating temperature
approx. 80°CWiring
Temperature sensor
Coolant (B11/4)
All-activity module
(N10)
Engine temperature Start engine and warm up
to operating temperature.
03Ignition ON Season-dependent,
approx. 20° CWiring
Temperature sensor
Ambient air (B14)
All-activity module
(N10)
Outside temperature
04Ignition ON ONWiring
F1k21
Blower motor (M2)
All-activity module
(N10)
Blower power supply
relay (F1k21) Blower stage 4FROM
05Ignition ON ONWiring
F1k26
Auxiliary fan (M4) Auxiliary fan relay FROM

2001 Mercedes-Benz ML320
1998-2005 HVAC Climate Control - 163 Chassis
me
Saturday, October 02, 2010 3:23:17 PMPage 169 © 2006 Mitchell Repair Information Company, LLC.

AIR CONDITIONING (TAU) DIAGNOSTIC FAULT MEMORY - AD83.30-P-4000GH
MODEL 163 with CODE (580) Air conditioning or Tempmatic for USA
(F1k26) All-activity module
(N10)
08Ignition ON ONWiring
F1k19
Heating water
circulation pump
(M13)
All-activity module
(N10)
Heating water
circulation pump relay
(F1k19) FROM
09Start engine12 barAD83.30-P-6000-09GH
Refrigerant pressure illuminates
Blower stage 4
10Start engineONAD83.30-P-6000-08GH
A/C compressor (A9) illuminates
Blower stage 4FROMAll-activity module
(N10)
A9
11Ignition ON YESWiring
Control module Air
conditioning (N19)
All-activity module
(N10)
Air conditioning
request NO

Air conditioning (TAU)
diagnosis previous
knowledge
AD83.30-P-
2000GH

Connect hand-held tester
(HHT), read out
diagnostic trouble code
memory
Model 163 up to 31.8.01
When a control module's fault memory is
read out, all the faults stored in the control
module are displayed, which means that
fault codes that do not concern the system
that is currently being read out can also
appear.
AD00.00-P-
2000-03C
Fault memory
Fault code Possible cause Note Remedy
(no
communication
with HHT
possible)
Diagnostic cable AD54.21-P-
6000-02GH

2001 Mercedes-Benz ML320
1998-2005 HVAC Climate Control - 163 Chassis
me
Saturday, October 02, 2010 3:23:17 PMPage 170 © 2006 Mitchell Repair Information Company, LLC.

1. Start vehicle engine and switch on air conditioning system.
2. Check entire air conditioning circuit using leak detector probe (1).
Remain for some time in areas where leaks are suspected.

Since refrigerant is heavier than air and sinks, always guide leak detector probe (1) underneath the locations
where leaks are suspected.
Line connections, screwed pipe connections, condensers and evaporators are the most frequent cause of
refrigerant leaks.
Fig. 155: Identifying Air Conditioning System Leak Detector Probe

CARRY OUT QUICK TEST ON AIR CONDITIONING SYSTEM - AR83.30-D-1209A
MODEL 163 with CODE (580) Air conditioning or Tempmatic for USA
MODELS 901.0/3 /4, 902.0/3 /4, 903.0/3 /4, 904.0/3 /4 with CODE (H06) Air conditioning
WE58.40-Z-1002-20AAir conditioning leak detector

2001 Mercedes-Benz ML320
1998-2005 HVAC Climate Control - 163 Chassis
me
Saturday, October 02, 2010 3:23:18 PMPage 185 © 2006 Mitchell Repair Information Company, LLC.

Fig. 156: Identifying Quick Test On Air Conditioning System - Shown On Models 901, 902, 903, 904
Shown on models 901, 902, 903, 904
Prerequisites for
testing
1Place vehicle with open
windows in the shade
2Set heater control valve
to "cold"
3
Set heating and
ventilation system to
fresh air mode

4
Fully open lateral
nozzles, center nozzles
and footwell flaps

5Start vehicle engine and
allow to idle
Inspecting
6Switch air conditioning
on
When the air conditioning is switched on, the vehicle
engine's idle speed must increase. No idle speed increase ?
Check function of refrigerant compressor RPM sensor in the
event of complaint ?


2001 Mercedes-Benz ML320
1998-2005 HVAC Climate Control - 163 Chassis
me
Saturday, October 02, 2010 3:23:18 PMPage 186 © 2006 Mitchell Repair Information Company, LLC.

Commercially available tools
Workshop equipment
DRAINING, EVACUATING AND REFILLING AIR CONDITIONING, CHECKING FUNCTION AND CHECKING FOR
LEAKS - AR83.30-P-1760GH
MODELS 163.113 /128 /136 /154 /157 /172 /174 /175 with CODE (580) Air conditioning or Tempmatic for
USA
Replace refrigerant compressor RPM sensor
Models 901-904
Not in model 163AR83.55-D-
5320A
7
Set blower rotary
switch to maximum
blower setting

8Check that refrigerant
flows free of bubbles
If the system is filled sufficiently, the refrigerant must flow
through the inspection glass (2) free of bubbles. A newly-
filled system may initially reveal bubbles. In this case, wait
for approx. 10 min. and check inspection glass again.
Does not reveal bubble-free flow ?

Check entire air conditioning circuit for leaks using leak
detector (3).AR83.30-D-
1209-01A
Air conditioning system leak detector*WE58.40-Z-
1002-20A
9Determine air outlet
temperature

Switch blower rotary switch to stage "1".
Insert sensor of temperature measurement device (1) into the
air outlet of the center nozzles.
After running for a period of 5 min., the air outlet temperature
must not be less than 2°C and more than 12°C. After 5 min., at
the latest, the refrigerant compressor must also be connected
and disconnected.
If the refrigerant compressor is disconnected at below 2°C ?
Check evaporator temperature switch. If the air outlet
temperature is not achieved ?
Check the connection and disconnection of the refrigerant
compressor or the refrigerant pressure upstream and
downstream of the refrigerant compressor.
*WH58.30-Z-
1005-08A
10
Switch air conditioning
off and shut vehicle
engine off

NumberDesignation
WH58.30-Z-1005-08ATemperature measuring device
WE58.40-Z-1002-20AAir conditioning leak detector

2001 Mercedes-Benz ML320
1998-2005 HVAC Climate Control - 163 Chassis
me
Saturday, October 02, 2010 3:23:18 PMPage 187 © 2006 Mitchell Repair Information Company, LLC.

Air conditioning system
Workshop equipment
REMOVE/INSTALL DEFROSTER VENT FLAP ACTUATOR MOTOR FOR WINDSHIELD - AR83.30-P-2006GH
MODEL 163.113 /154 /174 #A as of 289565, 163.113 #X as of 754620, 163.128/157/175
4evacuate
Filling
5Supplement oil for refrigerant
compressor The exact quantity determined when
drained must be used.
6Fill air conditioning system *BF83.30-P-
1001-01B
Testing
7Inspect air conditioning system for leaks
with leak detector *WE58.40-
Z-1002-20A

8
Risk of accident. Accidents may result if
the vehicle starts off unintentionally with
the engine running. Risk of injury from
bruises and burns if you hold your hand
near engine when it is started or when it
is running. Check function of air
conditioningSecure vehicle to prevent it from moving.
Wear closed and snug-fitting work clothes.
Do not grasp hot or rotating parts.
Run engine at idle speed for about 4
minutes and check all the component
functions which are of relevance for proper
operation of the air conditioning system.
AS00.00-Z-
0005-01A
NumberDesignationModel Series 163
BF83.30-P-1001-01BRefrigerantsFilling quantityg750
Specifications for Operating FluidsSheetBB00.40-P-0361-00A
WE58.40-Z-1002-20AAir conditioning leak detector
WE58.40-Z-1002-22AAir conditioning service station

2001 Mercedes-Benz ML320
1998-2005 HVAC Climate Control - 163 Chassis
me
Saturday, October 02, 2010 3:23:18 PMPage 189 © 2006 Mitchell Repair Information Company, LLC.