1997 MERCEDES-BENZ ML430 ignition

AD00.00-P-2000-03C
Connect hand-held tester (HHT), read out

diagnostic trouble code memory
Model 163 up to 31.08.01

Model 168

Workshop equipment/MB testers
(see Workshop Equipment Manual)

WE58.40-Z-1001-06A
Hand-held tester (HHT), order number 6511 0001 99

WE58.40-Z-1002-06A
Test cable (multiplexer)

WE58.40-Z-1009-06A
Adapter cable (HHT) for test connector (X11/4, 16-pin), order number 6511 0090 99

P42.35-0234-06

1
Connect hand-held tester (087) to

diagnosis test connector (X11/4) in

interior using test cable (multiplexer)

(094) and adapter cable (107) .

2
Switch on ignition.

3
According to instructions in display :

a)
Read out/erase fault memory

b)
Read out actual values

c)
Perform actuations

d)
Program control modules

4
Disconnect HHT.

087
Hand-held tester (HHT)

094
Test cable (multiplexer)

107
Adapter cable (HHT) for datalink

connector (X11/4, 16-pin)

X11/4
Diagnostic data link connector

Note system-specific deviations listed in respective diagnosis

description in chapter entitled "Diagnosis Previous Knowledge".
Stored faults possibly caused by cables being disconnected during

testing or by simulation must be erased from the fault memory once

the work is completed.

Copyright DaimlerChrysler AG 05.06.2006 CD-Ausgabe G/10/04 . This WIS print-out will not be recorde
d by Modification services.
Page 1

AD54.30-P-6000-02GH
HHT interface test electrics IC

t
A

Scope of test

Measuring instrument/

Test connection

Operation/

Requirement
Specified value
D
Possible cause/

Remedy

1.0
HHT interface

Connection between A1

and data link connector

(DTC readout) (X11/4)

X11/4

15
wb

A1

L
11

(B.11)

Ignition:
OFF

Remove A1

Coupling "B" (12-pin)

disconnected

T
5
W D
Cable

Copyright DaimlerChrysler AG 05.06.2006 CD-Ausgabe G/10/04 . This WIS print-out will not be recorde
d by Modification services.
Page 1

motor. See Fig. 2 .
PROGRAMMING
RECODING RADIO
1. Turn ignition on. Ensure CODE is displayed on radio display. Enter code numbers using radio station
buttons. For example, use station button No. 1 for code No. 1 and so on.
2. After first number is entered, CODE disappears and number entered is displayed followed by 4 dashes.
After entering 5-digits, confirm correct security code has been entered. If incorrect code has been entered,
entire code must be reentered.
3. Confirm entry of correct security code using "<" (less than) or ">" (more than) buttons. If an incorrect
code is entered, CODE will be displayed on radio display. If security code is entered incorrectly 3 times,
WAIT will be displayed and radio will be disabled for about 10 minutes.
4. If, after 3 more attempts, correct security code has not been entered, radio will be disabled for 60 minutes.
Radio disable time runs down only when radio is turned off.
VERSION CODING
Version coding is performed using a Mercedes-Benz Hand-Held Tester (HHT) and is on-screen menu guided.
After connecting HHT to DLC, vehicle communication is possible as soon as ignition key is inserted into
ignition switch (position of switch does not matter). Version coding menu, position 1, is reached via main menu
and control module adaptation, position 5. There are 2 possible version codings available: readout of version
code and transfer to new control module or readout of version code and to alter code.
To access A/C system version coding, position 2 must be selected and then position 7 for A/C system. Two
selections can be used: A/C system is installed or A/C system is not installed.
SELF-DIAGNOSTICS
RETRIEVING & ERASING DIAGNOSTIC TROUBLE CODES
Retrieving and erasing of Diagnostic Trouble Codes (DTC) must be performed using Mercedes-Benz Hand-
Held Tester (HHT). See HHT instructions for retrieving A/C-heater system related DTC. After noting codes,
see CLIMATE CONTROL DTC
table. To erase DTC, follow HHT instructions.
When retrieving DTC from A/C push button control module, short and open circuits cannot be differentiated
from each other in every instance. When accessing DTC from any control module memory, all stored DTC are
shown. As a result, some DTC shown will not appl
y to climate control system. CAUTION: Before disconnecting battery, obtain 5-digit radio security code from
vehicle owner. Radio will be disabled until properly recoded.
NOTE: Radio will not operate if power supply to radio is interrupted. Obtain 5-digit
radio security code from vehicle owner before disconnecting battery.

2001 Mercedes-Benz ML320
2000-01 MANUAL A/C-HEATER SYSTEMS ML 320, ML 430 & ML 55
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CLIMATE CONTROL DTC
SYSTEM TESTS
CONNECTING TEST EQUIPMENT
Remove radio to gain access to A/C push button control unit harness connector. Turn ignition off. Disconnect
control unit harness connector. Connect socket box Test Cable (163 589 01 63 00) to A/C push button control
unit and wiring harness. See Fig. 3
. Connect test cable to Socket Box (124 589 00 21 00). Connect test
equipment leads to socket box terminals as instructed in circuit tests.
DTCPossible Cause
B1232(1) Refrigerant Pressure Sensor
B1419Electromagnetic Clutch
(1)Check A/C refrigerant pressure sensor. See A/C REFRIGERANT PRESSURE SWITCH under
ELECTRICAL TESTS.
WARNING:To avoid injury from Accidental air bag deployment, read and carefully
follow all SERVICE PRECAUTIONS and DISABLING & ACTIVATING AIR
BAG SYSTEM procedures in AIR BAG SYSTEM SAFETY article in
GENERAL SERVICING.

2001 Mercedes-Benz ML320
2000-01 MANUAL A/C-HEATER SYSTEMS ML 320, ML 430 & ML 55
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FUNCTIONAL TEST PREPARATION
1. Check condition of fuses F16, F41, F43 and F44. See WIRING DIAGRAMS . Repair and/or replace
fuses and necessary.
2. Turn ignition on. Locate in-vehicle temperature sensor aspirator blower vent grille above anti-theft
indicator light. Place a half-inch square of tissue paper over aspirator blower vent grille. If paper stays on
vent grille, go to next step. If paper does not stay on vent grille, correct insufficient aspirator blower
ventilation.
3. Put shift lever in "P" and engage parking brake. Run engine at idle until it reaches normal operating
temperature, about 176°F (80°C). Ensure ambient (outside) temperature is greater than 58°F (15°C).
4. Manually open center and side air outlets. Ensure recirculation button is not depressed. Set blower speed
knob to position No. 1.
FUNCTION TEST
Defrost Mode
To check operation in defrost mode, set temperature selector knob to White range (vertical). Set mode control
knob to 12-o'clock position (vertical). Ensure A/C button indicator is illuminated. Air will vent from defrost and
center outlets and A/C compressor will engage. If operation is not as specified, perform the following in order:
Check voltage supply circuit Z50/2 between No. 16 fuse (15-amp) and connected components. See
VOLTAGE SUPPLY CIRCUIT Z50/2
under ELECTRICAL TESTS.
Check ground circuit. See GROUND CIRCUIT Z50/4 under ELECTRICAL TESTS.
Check in-vehicle temperature sensor signal voltage. See IN-VEHICLE TEMPERATURE SENSOR
under ELECTRICAL TESTS.
Check in-vehicle temperature sensor signal resistance. See IN-VEHICLE TEMPERATURE SENSOR
under ELECTRICAL TESTS.
Check icing protection temperature sensor signal voltage. See ICING PROTECTION
TEMPERATURE SENSOR under ELECTRICAL TESTS.
Check icing protection temperature sensor resistance. See ICING PROTECTION TEMPERATURE
SENSOR under ELECTRICAL TESTS.
Check activation voltage during temperature reduction. See ACTIVATION VOLTAGE
TEMPERATURE under ELECTRICAL TESTS.
Check activation voltage during temperature increase. See ACTIVATION VOLTAGE
TEMPERATURE under ELECTRICAL TESTS.
Check blend air flap actuator motor operation voltage. See BLEND AIR FLAP ACTUATOR MOTOR
under ELECTRICAL TESTS.
Check blend air flap actuator motor resistance. See BLEND AIR FLAP ACTUATOR MOTOR under
ELECTRICAL TESTS.
Check A/C button activation. See A/C BUTTON under ELECTRICAL TESTS.
Check A/C pressure switch. See A/C REFRIGERANT PRESSURE SWITCH under ELECTRICAL NOTE: Function test steps must be performed in order given.

2001 Mercedes-Benz ML320
2000-01 MANUAL A/C-HEATER SYSTEMS ML 320, ML 430 & ML 55
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TESTS.
Normal Ventilation In Regulating Mode
To check normal ventilation in regulating mode, set temperature selector knob to White range (vertical). Set
mode control knob to 4-o'clock position. Ensure A/C button indicator is illuminated. Air will vent from upper
and lower outlets and A/C compressor will engage. Ambient air will flow from center outlet and coolant
circulation pump will operate. If operation is not as specified, perform the following in order:
Check A/C button activation. See A/C BUTTON under ELECTRICAL TESTS.
Check A/C pressure switch. See A/C REFRIGERANT PRESSURE SWITCH under ELECTRICAL
TESTS.
Economy Setting Not In Heating Mode
To check economy setting without heating mode activated, set temperature selector knob to Blue range. Set
mode control knob to the 9-o'clock position. Ensure A/C button indicator is not illuminated. Ambient air will
flow from center outlet and A/C compressor will NOT be engaged. If operation is not as specified, perform the
following:
Check A/C button activation. See A/C BUTTON under ELECTRICAL TESTS.
Economy Setting In Heating Mode
To check economy setting with heating mode activated, set temperature selector knob to Red range. Set mode
control knob to the 4-o'clock position. Ensure A/C button indicator is not illuminated. Heated air will flow from
lower, upper and center outlets and A/C compressor will NOT be engaged. If operation is not as specified,
perform the following:
Check A/C button activation. See A/C BUTTON under ELECTRICAL TESTS.
Recirculation Mode
To check recirculation mode, press fresh/recirculation button. Ensure fresh/recirculation indicator is
illuminated. Set blower speed knob to position No. 4. Blower fan noise will increase noticeably. If operation is
not as specified, check wiring between recirculated air flap element, heater-A/C switch and No. 16 fuse (15-
amp).
ELECTRICAL TESTS
Voltage Supply Circuit Z50/2
1. Connect socket box to A/C push button control unit and wiring harness. See CONNECTING TEST
EQUIPMENT . Turn ignition on, with engine off. Connect voltmeter positive lead to socket box terminal
No. 7 and negative lead to terminal No. 9.
2. Voltage should be 11-14 volts. If voltage is not as specified, check voltage supply circuit Z50/2 between
No. 16 fuse (15-amp) and connected components. See WIRING DIAGRAMS
. Repair as necessary.

2001 Mercedes-Benz ML320
2000-01 MANUAL A/C-HEATER SYSTEMS ML 320, ML 430 & ML 55
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Ground Circuit Z50/4
1. Connect socket box to A/C push button control unit wiring harness connector. See CONNECTING
TEST EQUIPMENT . Turn ignition off. Ensure A/C push button control unit is not connected to socket
box.
2. Connect ohmmeter positive lead to socket box terminal No. 9 and negative lead to body ground.
Resistance should be zero. If resistance is not as specified, check control unit ground circuit Z50/4. See
WIRING DIAGRAMS
. Repair as necessary.
In-Vehicle Temperature Sensor
1. Connect socket box to A/C push button control unit and wiring harness. See CONNECTING TEST
EQUIPMENT . Connect voltmeter positive lead to socket box terminal No. 12 and negative lead to
terminal No. 9.
2. Turn ignition on. Turn temperature control knob to Red range detent. Voltage should be 1.9 volts at 68°F
(20°C). If voltage is as specified, go to next step. If voltage is not as specified, check in-vehicle
temperature sensor circuits. See WIRING DIAGRAMS
. Repair as necessary. If circuits are okay,
replace in-vehicle temperature sensor.
3. Turn ignition off. Disconnect test cable from A/C push button control unit. Connect ohmmeter positive
lead to socket box terminal No. 2 and negative lead to terminal No. 12. Measure temperature sensor
resistance at specified temperatures. See IN
-VEHICLE TEMPERATURE SENSOR RESISTANCE
table.
4. If resistance is not as specified, check wiring harness and connectors between A/C push button control
unit, in-vehicle temperature sensor, blend air flap actuator position sensor and temperature regulator
switch. Repair as necessary.
IN-VEHICLE TEMPERATURE SENSOR RESISTANCE
Icing Protection Temperature Sensor
1. Connect socket box to A/C push button control unit and wiring harness. See CONNECTING TEST
EQUIPMENT . Connect voltmeter positive lead to socket box terminal No. 11 and negative lead to
terminal No. 9.
2. Turn ignition on. Voltage should be 2.0-2.4 volts at 32°F (0°C) and 1.4-1.8 volts at 59°F (15°C). If
voltage is as specified, go to next step. If voltage is not as specified, check icing protection temperature
sensor circuits. See WIRING DIAGRAMS
. Repair as necessary. If circuits are okay, replace icing
protection temperature sensor.
3. Turn ignition off. Disconnect test cable from A/C push button control unit. Connect ohmmeter positive
lead to socket box terminal No. 3 and negative lead to terminal No. 11. Measure temperature sensor
resistance at specified temperatures. See ICING PROTECTION TEMPERATURE SENSOR
RESISTANCE table.
Sensor Temperature - °F (°C)Ohms
68 (20)2100
77 (25)1700
104 (40)900

2001 Mercedes-Benz ML320
2000-01 MANUAL A/C-HEATER SYSTEMS ML 320, ML 430 & ML 55
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4. If resistance is not as specified, check wiring harness between temperature sensor and control unit. Repair
as necessary. If wiring harness is okay, replace icing protection temperature sensor.
ICING PROTECTION TEMPERATURE SENSOR RESISTANCE
Activation Voltage Temperature
1. Connect socket box to A/C push button control unit and wiring harness. See CONNECTING TEST
EQUIPMENT . Connect voltmeter positive lead to socket box terminal No. 2 and negative lead to
terminal No. 9.
2. Turn ignition on. Turn temperature control knob to Blue range detent. Voltage should be more than 2.0
volts. Turn temperature control knob from Blue range detent to Red range detent. Voltage should be more
than 3.0 volts.
3. If voltage is as specified, go to next step. If voltage is not as specified, check recirculated air switch
circuits. See WIRING DIAGRAMS
. Repair as necessary. If circuits are okay, replace recirculated air
switch.
4. Connect voltmeter positive lead to socket box terminal No. 5 and negative lead to terminal No. 9. Turn
ignition on. Turn temperature control knob to Blue range detent. Voltage should be more than 3.0 volts.
Turn temperature control knob from Blue range detent to Red range detent. Voltage should be more than
4.0 volts.
5. If voltage is not as specified, check recirculated air switch circuits. See WIRING DIAGRAMS
. Repair
as necessary. If circuits are okay, replace recirculated air switch.
Blend Air Flap Actuator Motor
1. Connect socket box to A/C push button control unit and wiring harness. See CONNECTING TEST
EQUIPMENT . Connect voltmeter positive lead to socket box terminal No. 1 and negative lead to
terminal No. 9.
2. Turn ignition on. Turn temperature control knob to Blue range detent. Voltage should be less than one
volt. Turn temperature control knob from Blue range detent to Red range detent. Voltage should be 11.0-
14.0 volts.
3. If voltage is as specified, go to next step. If voltage is not as specified, check blend air flap actuator motor
wiring harness circuits. See WIRING DIAGRAMS
. Repair as necessary. If circuits are okay, replace
blend air flap actuator motor.
4. Connect voltmeter positive lead to socket box terminal No. 8 and negative lead to terminal No. 9. Turn
ignition on. Turn temperature control knob to Red range detent. Voltage should be less than one volt.
Turn temperature control knob from Red range detent to Blue range detent. Voltage should be 11.0-14.0
volts.
5. If voltage is as specified, go to next step. If voltage is not as specified, check blend air flap actuator motor
wiring harness circuits. See WIRING DIAGRAMS
. Repair as necessary. If circuits are okay, replace
Sensor Temperature - °F (°C)Ohms
43 (6)3600
59 (15)2300
72 (22)1700
77 (25)1500

2001 Mercedes-Benz ML320
2000-01 MANUAL A/C-HEATER SYSTEMS ML 320, ML 430 & ML 55
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