W124032 Fault Memory Diagnosis

Diagnosis - Fault memory Preceding work:

Testing, adjusting engine (07-1100)

Note regarding fault memory The HFM-SFI control module (N3/4) features a fault memory. Faults are detected and stored according to the categories stated below: D Fault exists constantly D Fault exists for longer than 3 seconds D Loose contact faults which have occured 5 times during a journey The fault memory is retained even after disconnecting the vehicle battery. Faults which no longer occur are erased again automatically after not more than 19 journeys. A journey has been accomplished if: D D D

Road speed > 4 km/h Engine speed > 700/min Engine switched off for 30 seconds

The stored faults can be read out at the data link connector (X11/4) with ignition "ON" or "with engine running". Diagnosis by displaying the on/off ratio has been discontinued.

Note regarding self-adaptation of mixture formation On vehicles fitted with catalytic converter, the lambda control determines the injection time so exactly as to always achieve the fuel/air ratio of lambda 1 in all operation states (corresponds to 14.7 kg air to 1 kg fuel). If faults occur as a result of: D D D D D D

ingress of air wear or coking of fuel injection valves wear to engine contact resistance in mass air flow sensor defective diaphragm pressure regulator defective regeneration switchover valve

the HFM-SFI control module automatically performs a correction of the mixture formation. The correction parameters are constantly calculated and permanently stored. Self-adaptation is performed at idle speed and at part throttle. The correction is in each case not more than 25 % toward a rich or lean mixture. Following repair work, the HFM-SFI control module once again performs selfadaptation automatically after about 10 trips. After rectifying the faults stated or installation of an HFM-SFI control module from another vehicle for test purposes, the self-adaptation must be reset to the mean value (see Resetting and reactivating memory of HFM-SFI control module j 11/5).

Diagnosis - Fault memory

Notes regarding automatic recognition of vehicle version Vehicles up to 02/94 (HHT diagnosis code up to 42) The HFM-SFI control module recognizes the following versions when the vehicle is operated for the first time and stores them: D D D D D

TWC/without TWC Manual/automatic transmission 4-speed/5-speed automatic transmission Cruise control Electronic accelerator

D

H version

D I version After replacing the HFM-SFI control module or installing an HFM-SFI control module from another vehicle for test purposes, the stored data must be erased and recognition re-activated (see Resetting and re-activating memory of HFM-SFI control module j 11/5). Reprograming control module Prerequisites for programing: D Battery voltage t min. 11 V D Road speed signal tV=0 D Rpm signal tn=0 D Driving stage t P/N = 1 D Idle speed contact closed t LLK = 1 (Important: vehicle must not be moved during programing.) D Drive off vehicle t V => 5 km/h (Transmission variant is not programed until this is done.)

Diagnosis - Fault memory

Notes regarding automatic recognition of mechanical end stop of closed throttle valve (except with EA or CC) The mechanical end stop of the closed throttle valve at idle speed is detected by the idle speed control actuator and stored in the HFM-SFI control module. After replacing the HFM-SFI control module or the actuator, the mechanical end stop of the throttle valve must be re-detected and stored (Resetting and reactivating memory of HFM-SFI control module j 11/5). Note on variant coding of vehicles as of 03/94 (HHT diagnosis code 45 or higher) The HFM-SFI control module features a variant coding as of 03/94. The coding can only be performed with the Hand-Held Tester (automatically and manually, see notes on HHT j 11/4). The following vehicle versions should be noted for the coding: D D D D D D D D D D

Vehicle model TWC Without TWC 5-speed manual transmission 4-speed automatic transmission 5-speed automatic transmission Cruise control ASR Electronic traction support National version

Note on stage 2 or stage 2a drive authorization system (DAS) A stage 2 drive authorization system is installed on vehicles up to 5/96. Activation or deactivation is by means of the RCL remote control. A stage 2a drive authorization system is installed on vehicles as of 6/96 (except model 124.066 as of 3/96). Activation or deactivation is by means of transponder technology via the ignition key. As soon as the key is turned in the steering lock, the DAS infrared control module receives a signal and enables the engine control via the CAN data bus. Unlocking and locking the vehicle with the mechanical key has effect the The drive authorization system. It is therefore not possible to install HFM-SFI control or the IRCL control module inno another vehicle for test purposes. D Vehicles as of 12/94 (HHT the diagnosis code 46) aremodule fitted with an immobilizer stage 2 (except modelon 124). immobilizer is now activated by the IRCL control module through the CAN data bus On model 124.066 as of 3/96 the DAS infrared control module is activated by the infrared remote control control module. Note re immobilizer D Model 124 with manual transmission is fitted as standard as of 03/94 with an immobilizer which acts on the HFM gasoline injection and ignition system. The immobilizer interrupts the fuel pump relay and terminal 15 to the HFM control unit. On all other models, only terminal 50 to the starter is interrupted. Before commencing the test, it is important to ensure that the locking functions of the immobilizer are deactivated.

M If a new HFM control unit is installed for test purposes, no more than 40 start operations may be performed as otherwise the control units will then be interlocked. Furthermore, identification has to be initiated and the vehicle identity no. registered (see HHT actual values "Drive authorization system" menu point 3/6).

Diagnosis - Fault memory

Notes on HHT D

D

D

D

D

Troubleshooting with HHT Fault memory: Select current faults When the current state changes, e.g. due to intermittent contact at a plug connection, the change is signaled optically and acoustically so that troubleshooting can be accomplished directly with the HHT. Intermittent contact Intermittent contacts are stored, when they occur several times within a certain time period. For this reason they can only occur as stored faults and never as current faults. Settings All settings for the actual values measured with the HHT are given in the Diagnosis Manual, Engine, Volume 1, Chapter A. Actual values for coolant temperature, intake air temperature and air mass In the event of discontinuity or short circuit the system switches over immediately to a substitute value for the current actual value, which is very close to the actual value. This makes it hard to recognize a fault. Readout of the fault is only possible via the fault memory. Actual value for engine speed When set to engine speed the HHT display indicates the nominal value for the idle speed calculated by the control unit on the left and the actual RPM on the right. These two values should deviate from one another only slightly. The permissible tolerances have not yet been established.

Diagnosis - Fault memory

Notes on HHT (continued) D

Drive authorization system stage 2 (DAS) Upon replacement of the ME control module, variant coding must be followed by identification with input of the vehicle identification no. (see HHT actual value "Drive authorization system" menu point 3/6).

D

Adjustment program for models 129, 140 from 6/95 (except I,H, ASR) and model 210 The following adjustments can be carried out using the HHT: 1. Adjustment of ignition for various fuels (RON) 2. Adjustment of the fuel volume in the event of complaint (MKV) 3. Adjustment of idle speed in selector lever position P/N 4. Adjustment of idle speed, selector lever in drive stage 5. CO setting for vehicles without TWC

Diagnosis - Fault memory

D

Variant coding with HHT as of 03/94 (HHT diagnosis code 45 or higher) a) Before removing the HFM control unit, read and store existing code number with HHT (menu point 6 "Variant coding"). After installing the new control unit, enter stored code number. Note When returning the new control unit to the parts depot, the code number must be erased. b) If it is not possible to read the code number, determine the vehicle version, refer to the Parts Microfilm Group 54 for the relevant code number and enter it manually with the HHT. c) If installing the control module from another vehicle with the same part no. but a different code number (only possible to 12/94 excl. model 124) as a check, proceed as follows: D Read and note the code number of the vehicle under repair. D Exchange control units. D Read and note code number of replaced control unit. D Enter code number of the original control unit in the replaced control unit. D Perform a function test. D Before reinstalling the control unit, enter the code number read out at the outset. D Reinstall control unit.

Preconditions for test with pulse counter

Erasing fault memory

Note: Reading fault memory with the pulse counter is only possible on vehicles up to HHT diagnosis code 46. Vehicles with a diagnosis code 49 or higher (incremental control) now only possible with HHT! D Connect pulse counter to the test coupling for diagnosis (X11/4) according to the connection diagram.

a) Press start button 2 - 4 s ("fault code" appears). b) Press start button 6 - 8 s; the fault displayed previously is cancelled. c) Repeat steps a) and b) until fault code "I" appears (no more faults appear). Resetting and re-activating memory of HFM control unit a) Erase fault memory.

Reading fault memory a) Ignition: ON b) Press start button for 2 - 4 seconds. c) Read out fault code and note. d) Once again press start button. e) Read out fault code. Repeat steps d) and e) as often as necessary until the first fault code re-appears.

b) After fault code "I" appears, press the start button 6 - 8 s. c) Switch off ignition and wait at least 2 seconds. d) Switch on ignition and wait at least 10 seconds before starting engine. Note With Bosch control units up to 8/93 it is necessary to press the start button for 5 - 6 s to cancel the faults and for 8 - 9 s to reset and reactivate the memory.

Special tools

124 589 19 21 00

140 589 14 63 00

Diagnosis - Fault memory

Commercially available tools and testers, MB testers (see Workshop Equipment Manual) Designation

e.g. make, order no.

Hand-Held Tester

Mercedes-Benz AG D-70322 Stuttgart VP/SDI 6511 00 01 99

Test cable (multiplexer)

Mercedes-Benz AG D-70322 Stuttgart VP/SDI 6511 00 40 99

Test cable (HHT) for test coupling (X11/4, 8- or 16-pin)

Mercedes-Benz AG D-70322 Stuttgart VP/SDI 6511 00 50 99

Diagnosis - Fault memory

Connection diagram for pulse counter/Hand-Held Tester model 124 Pulse counter Black cable terminal 31 (ground) Red cable terminal 15 (ignition) Hand-Held Tester Black cable terminal 31 (ground) White cable terminal 15 (ignition) Red cable terminal 30

socket 1 socket 16

socket 1 socket 16 battery+ or X4/10

Yellow cable pulse counter/Hand-Held Tester HFM-SFI control unit socket 8 Electronic accelerator pedal/Tempomat (SA) socket 14 Diagnosis module (I only)

socket 3

Fig. 1 013 087 X11/4

Pulse counter (alternatively with Hand-Held Tester 087) Hand-Held Tester (alternatively with pulse counter 013) Test coupling for diagnosis, 16-pin (pulse signal)

P07-5730-57A

Diagnosis - Fault memory

Connection schematic for pulse counter/Hand-Held Tester, models 129, 140 , 202 and 210. Note: Reading fault memory with the pulse counter is only possible on vehicles up to HHT diagnosis code 46. Vehicles with a diagnosis code 49 or higher (incremental control) now only possible with HHT! Connect red cable from pulse counter to socket 3, black cable from pulse counter to socket 1, yellow cable from pulse counter as follows: HFM-SFI control unit Electronic accelerator/cruise control (SA) Base module (except models 202, 210) Speed signal (TN, output, except models 202, 210) Speed signal (TN, output, models 202, 210)

socket 4 socket 7 socket 8 socket 13 socket 17

Diagnostic module (I only)

socket 19

Fig. 2 013 075 087 094 X11/4

Pulse counter (alternatively with Hand-Held Tester 087) Pulse counter adapter Hand-held Tester (alternatively with pulse counter 013) Multiplex cable Test coupling for diagnosis, pulse readout (38-pin)

P07-5925-57

Diagnosis - Fault memory Fault code

Possible cause

Remedy/Test step 1)

N 7)

A

I 2 2 2 2

No fault recognized in system

-

002 003 004 005

HFM-SFI, PEC engine coolant temperature sensor (B11/3) short circuit

j 23 t 8.0

HFM-SFI, PEC engine coolant temperature sensor (B11/3) open circuit

j 23 t 8.0

HFM-SFI, PEC engine coolant temperature sensor (B11/3) implausible

j 23 t 8.0

HFM-SFI, PEC engine coolant temperature sensor (B11/3) loose contact

Contacts at connectors B11/3 or N3/4

3 3 3

006 007 008

Intake air temperature sensor (B17) short circuit

j 23 t 9.0

Intake air temperature sensor (B17) open circuit

j 23 t 9.0

Intake air temperature sensor (B17) loose contact

Contacts at connectors B11/3 or N3/4

4

009

Air mass flow meter (B2/5) air mass flow implausibly high

j 23 t 4.0-5.0 Engine not operating freely

4 5

0I0 0II

Air mass flow meter (B2/5) open circuit

j 23 t 4.0-5.0

Idle speed contact at idle speed control actuator (M16/6s1), throttle valve angle implausibly large

j 25 t 4.0 (not with EA or CC) j 23 t 11.0 (only with EA or CC)

5

0I2

Idle speed contact at idle speed control actuator (M16/6s1), air mass implausibly large

j 25 t 4.0 (not with EA or CC) j 23 t 11.0 (only with EA or CC)

1) 7)

Observe prerequisites for testing, see j 22. Only possible up to approx. 2/95

Diagnosis - Fault memory Fault code

Possible cause

Remedy/Test step 1)

N 7)

A

5

0I2

Idle speed contact at idle speed contro actuator (M16/6s1) air mass implausibly large

j 25 t 4.0 (not with EFP or TPM) j 23 t 11.0 (only with EFP or TPM) Hot film MAF sensor (B2/5)

5

0I3

Idle speed contact at idle speed control actuator (M16/6s1) loose contact

j 25 t 4.0 (not with EA or CC) j 23 t 11.0 (only with EA or CC)

6

0I4

Not with EA or CC Throttle valve actual value potentiometer in idle speed control actuator (M16/6r1) implausibly high

j 25 t 3.0

6

0I5

Not with EA or CC Throttle valve actual value potentiometer in idle speed control actuator (M16/6r1) implausibly low

j 25 t 3.0

6

0I6

Not with EA or CC Throttle valve actual value potentiometer in idle speed control actuator (M16/6r1) loose contact

j 25 t 3.0

7

0I7

Not with EA or CC Drive actual value potentiometer in idle speed control actuator (M16/6r2) implausibly high

j 25 t 1.0, 2.0

7

0I8

Not with EA or CC Drive actual value potentiometer in idle speed control actuator (M16/6r2) implausibly low

j 25 t 1.0, 2.0

1) 7)

Pay attention to preconditions for test, see j 22. Only possible up to approx. 2/95

Diagnosis - Fault memory

Fault code

Possible cause

Remedy/Test step 1)

j 25 t 1.0, 2.0

N 7)

A

7

0I9

8

020

Not with EA or CC Drive actual value potentiometer in idle speed control actuator (M16/6r2) loose contact Idle speed control at bottom control stop

8

02I

Idle speed control at top control stop

8

022

CC/EA signals emergency running mode

9 2)

023

9 2)

024

9 2)

025

with TWC Oxygen sensor (G3/2) sensor voltage too large with TWC Oxygen sensor (G3/2) too cold or open circuit with TWC Oxygen sensor (G3/2) sensor voltage implausible

I0

026

only I, except model 124

Unmetered air, throttle valve jamming Cruise control or el. throttle to emergency running Unmetered air, throttle valve jamming Cruise control or el. throttle to emergency running Air ingress, throttle valve sticks. Adjust throttle control (on automatic). Reset HFM-SFI/MFI control module memory. j 23 t 14.0 j 23 t 14.0 j 23 t 14.0 j 23 t 16.0

Oxygen sensor downstream of TWC (G3/1) sensor voltage too large

I0

027

only I, except model 124

j 23 t 16.0

Oxygen sensor downstream of TWC (G3/1) too cold or open circuit

2) 7)

Fault code "9" may be displayed up to 12/92 although no fault exists. Only possible up to approx. 2/95

Diagnosis - Fault memory Fault code

Possible cause

Remedy/Test step 1)

N 7)

A

II

030

with TWC Oxygen sensor heater of oxygen sensor (G3/2) current too large

j 23 t 15.0

II

03I

with TWC Oxygen sensor heater of oxygen sensor (G3/2) short circuit

j 23 t 15.0

I2

032

only I, except 124

j 23 t 17.0

Oxygen sensor heater of oxygen sensor downstream of TWC (G3/1) current too small

I2

033

only I, except 124

j 23 t 17.0

Oxygen sensor heater of oxygen sensor downstream of TWC (G3/1) current too large

I2

034

only I, except 124

j 23 t 17.0

Oxygen sensor heater of oxygen sensor downstream of TWC (G3/1) short circuit

I3

035

with TWC Lambda control is at rich stop, mixture too lean

Unmetered air, fuel injection valves, diaphragm pressure regulator

I3

036

with TWC Lambda control is at lean stop, mixture too rich

Unmetered air, fuel injection valves, diaphragm pressure regulator

I4 I4 I5 I5

037 038 039 040

Fuel injection valve (Y62y1) cylinder 1 short circuit to positive

j 23 t 19.0

Fuel injection valve (Y62y1) cylinder 1 open circuit/short circuit to ground

j 23 t 19.0

Fuel injection valve (Y62y2) cylinder 2 short circuit to positive

j 23 t 20.0

Fuel injection valve (Y62y2) cylinder 2 open circuit/short circuit to ground

j 23 t 20.0

1) 7)

Observe prerequisites for testing, see j 22. Only possible up to approx. 2/95

Diagnosis - Fault memory Fault code

Possible cause

Remedy/Test step 1)

N 7)

A

I6 I6 I7 I7 I8 I8 I9 I9 20

04I 042 043 044 045 046 047 048 049

Fuel injection valve (Y62y3) cylinder 3 short circuit to positive

j 23 t 21.0

Fuel injection valve (Y62y3) cylinder 3 open circuit/short circuit to positive

j 23 t 21.0

Fuel injection valve (Y62y4) cylinder 4 short circuit to positive

j 23 t 22.0

Fuel injection valve (Y62y4) cylinder 4 open circuit/short circuit to positive

j 23 t 22.0

Fuel injection valve (Y62y5) cylinder 5 short circuit to positive

j 23 t 23.0

Fuel injection valve (Y62y5) cylinder 5 open circuit/short circuit to positive

j 23 t 23.0

Fuel injection valve (Y62y6) cylinder 6 short circuit to positive

j 23 t 24.0

Fuel injection valve (Y62y6) cylinder 6 open circuit/short circuit to positive

j 23 t 24.0

with TWC Self-adaptation idle too rich

20

050

with TWC Self-adaptation idle too lean

Unmetered air, fuel injection valves, diaphragm pressure regulator, wear to motor (reset self-adaptation after repairs, see j 11/3) Unmetered air, fuel injection valves, diaphragm pressure regulator, wear to motor (reset self-adaptation after repairs, see j 11/3)

1) 7)

Observe prerequisites for testing, see j 22. Only possible up to approx. 2/95

Diagnosis - Fault memory Fault code

Possible cause

Remedy/Test step 1)

Unmetered air, fuel injection valves, diaphragm pressure regulator, wear to motor (reset self-adaptation after repairs, see j 11/3) Unmetered air, fuel injection valves, diaphragm pressure regulator, wear to motor (reset self-adaptation after repairs, see j 11/3) Unmetered air, fuel injection valves, diaphragm pressure regulator, wear to motor (reset self-adaptation after repairs, see j 11/3) Unmetered air, fuel injection valves, diaphragm pressure regulator, wear to motor (reset self-adaptation after repairs, see j 11/3)

N 7)

A

20

05I

with TWC self-adaptation lower part throttle too rich

20

052

with TWC self-adaptation lower part throttle too lean

20

053

with TWC self-adaptation upper part throttle too rich

20

054

with TWC self-adaptation upper part throttle too lean

2I 2I 2I

06I 062 063

Ignition output stage 3 or ignition coil (T1/3) for cylinder 1 fails

j 24 t 13.0, 16.0 and 19.0

Ignition output stage 3 or ignition coil (T1/3) for cylinder 6 fails

j 24 t 13.0, 16.0 and 19.0

Ignition output stage 3 or ignition coil (T1/3) amperage not reached

j 24 t 13.0, 16.0 and 19.0

1) 7)

Observe prerequisites for testing, see j 22. Only possible up to approx. 2/95

Diagnosis - Fault memory Fault code

Possible cause

Remedy/Test step 1)

N 7)

A

22 22 22 23 23 23 24 24

055 056 057 058 059 060 064 065

Ignition output stage 1 or ignition coil (T1/1) for cylinder 2 fails

j 24 t 11.0, 14.0 and 17.0

Ignition output stage 1 or ignition coil (T1/1) for cylinder 5 fails

j 24 t 11.0, 14.0 and 17.0

Ignition output stage 1 or ignition coil (T1/1) amperage fails

j 24 t 11.0, 14.0 and 17.0

Ignition output stage 2 or ignition coil (T1/2) for cylinder 3 fails

j 24 t 12.0, 15.0 and 18.0

Ignition output stage 2 or ignition coil (T1/2) for cylinder 4

j 24 t 12.0, 15.0 and 18.0

Ignition output stage 2 or ignition coil (T1/2) amperage not reached

j 24 t 12.0, 15.0 and 18.0

Crankshaft position sensor (L5) signal not recognized/implausible

j 24 t 7.0

Crankshaft position sensor (L5) no solenoid (segment control) Crankshaft position sensor (L5) teeth no. implausible (incremental control)

j 24 t 7.0

24 25

066 067

Crankshaft position sensor (L5) engine speed implausibly high

j 24 t 7.0

Camshaft position sensor (L5/1) implausible/not recognized (segment control) Camshaft Hall-effect sensor (B6/1) implausible/not recognized (incremental control)

j 24 t 8.0 j 24 t 9.0

1) 7)

Observe prerequisites for testing, see j 22. Only possible up to approx. 2/95

Diagnosis - Fault memory Fault code

Remedy/Test step 1)

Possible cause

N 7)

A

26

068

H, ASR)

j 23 t 25.0

except I and model 210. Models 129/140 only up to 5/95 except H, ASR)

j 23 t 25.0

except I and model 210. Models 129/140 only up to 5/95 except HFM-SFI reference resistor (R16/5) short circuit to ground

26

069

Variable reference resistor HFM-SFI (4-cylinders) (R16/5) short-circuit to positive

27 27 28 28 30 3I

32 32

1) 7)

070 071 072 073 076 077

Speed signal (DI/KSS) (output), short-circuit to ground

j 23 t 10.0

Speed signal (DI/KSS) (output), short-circuit to positive

j 23 t 10.0

Vehicle speed signal not recognized

j 23 t 27.0

Vehicle speed signal implausibly high

j 23 t 27.0

FP relay module (K27) open-circuit/short-circuit

j 23 t 6.0

without TWC except models 210. Models 129/140 up to 5/95 CO potentiometer (R33) short circuit to positive

j 23 t 26.0

078

without TWC except models 210. Models 129/140 up to 5/95 CO potentiometer (R33) loose contact

j 23 t 26.0

079 080

Knock sensors 1 (A16) open circuit

Knock sensors

Knock sensors 2 (A16) open circuit

Knock sensors

Observe prerequisites for testing, see j 22. Only possible up to approx. 2/95

Diagnosis - Fault memory Fault code

N 7)

A

33

08I

Possible cause

Remedy/Test step 1)

Maximum retardation reached at at least 1 cylinder

Increased knocking tendency as a result of poor fuel, coked combustion compartments or mechanical damage

33

082

Differences in ignition angle between individual cylinders > 6° CKA

34

083 084

Knock control analysis circuit in HFM-SFI control module (N3/4) faulty

085

with TWC, except

35 3)

36 36 37

086 087 088

38

089

1) 3) 7)

Short-time self-adaptation idle speed/part load exceeded

A

Increased knocking tendency as a result of poor fuel, coked combustion compartments or mechanical damage N3/4 Short-time fault in mixture formation system j 23 t 28.0

Model 124, 129 and 140 secondary air pump switchover valve (Y32) and/or secondary air pump electromagnetic coupling (Y33), model 202 secondary air pump switchover valve (Y32) and/or secondary air pump relay (K17) open circuit/short circuit Purge control valve (Y58/1) open circuit/short circuit

j 23 t 29.0-30.0

Purge control valve (Y58/1) short circuit to positive

j 23 t 29.0-30.0

with automatic transmission (AT) Upshift delay switchover valve (Y3/3) open circuit/short circuit

j 23 t 34.0

Camshaft timing actuator (Y49) short circuit to positive

j 23 t 31.0-32.0

Observe prerequisites for testing, see j 22. Pulse readout "35" is not a fault on vehicles in Australia version as no pump is fitted. Only possible up to approx. 2/95

Diagnosis - Fault memory Fault code

N 7)

A

38 39

090 09I

Possible cause

Remedy/Test step 1)

Camshaft timing actuator (Y49) open circuit/short circuit to ground

j 23 t 31.0-32.0

only I H

j 23 t 38.0-40.0

EGR switchover valve (Y27) short circuit to positive

39

092

only I H

j 23 t 38.0-40.0

EGR switchover valve (Y27) open circuit/short circuit to ground

40

093

with AT Transmission overload protection switch (S65) short circuit to ground

j 24 t 10.0

40

094

with AT Transmission overload protection switch (S65) switch closed and 2nd gear recognized

j 24 t 10.0

40

095

with AT Transmission overload protection switch (S65) switch open and 2nd gear recognized

j 24 t 10.0

40

096

with AT Transmission overload protection switch (S65) implausible

j 24 t 10.0

4I 42 42

097 098 099

Fault in CAN communication from HFM-SFI control module (N3/4)

j 23 t 37.0

Fault in CAN communication from ASR control module (N30/1)

j 23 t 36.0

Fault in CAN communication from EA control module (N4/1) or CC/idle speed control module (N4/3)

j 23 t 36.0

1) 7)

Pay attention to preconditions for test, see j 22. Only possible up to approx. 2/95

Diagnosis - Fault memory Fault code

Possible cause

Remedy/Test step 1)

N 7)

A

42

I00

Fault in CAN communication from diagnostic module (N59/1), only I

j 23 t 36.0

43 44

I0I I02

No starter signal terminal 50

j 23 t 7.0

only H

j 23 t 44.0

TWC thermocouple (B16/6) temperature too large

44

I03

only H

j 23 t 44.0

TWC thermocouple (B16/6) temperature too small

45

I04

only with EA or CC Safety fuel cutoff from electronic accelerator pedal or cruise control activated

j 23 t 12.0 j 23 t 13.0

46 46

I05 I06 I07 4)

Variable resonance intake manifold switchover valve (Y22/6) short circuit to positive

j 23 t 33.0

Variable resonance intake manifold switchover valve (Y22/6) open circuit/short circ. to ground

j 23 t 33.0

Dwell angle control at ignition output stage stop, short circuit to ground

j 24 t 14.1 and 15.1 N3/4

I08

only I

j 23 t 18.0

48

Relay of oxygen sensor heater downstream of TWC (K35) short circuit to positive

48

I09

only I

j 23 t 18.0

Relay of oxygen sensor heater downstream of TWC (K35) open circuit/short circuit to ground

1) 4) 5) 7)

Pay attention to preconditions for test, see j 22. As of 06/93 As of 01/94 Only possible up to approx. 2/95

Diagnosis - Fault memory Fault code

N 49

7)

Possible cause

Remedy/Test step 1)

Voltage supply terminal 87 U at HFM-SFI control module (N3/4) implausible

j 23 t 2.0

A II0

49 50

III II2 II3 5) II4 5) II5 5) II6 6) II7 6)

Voltage supply terminal 87 U at HFM-SFI control module (N3/4) undervoltage

j 23 t 2.0

HFM-SFI control module (N3/4)

N3/4

HFM-SFI control module (N3/4) is not coded

code N3/4

Incorrect control module identification from N3/4

code N3/4, replace N3/4 if necessary

Incorrect control module coding bytes from N3/4

code N3/4, replace N3/4 if necessary

Fault in CAN communication from RCL control module (N54)

j 23 t 36.1

Attempt at starting made with RCL locking system locked

Inadvertent wrong operation, erase fault memory

I20

As of 6/95 129/140 except I H, 210 except I ETS signal not recognized, open-circuit/short-circuit to positive

I2I

As of 6/95 129/140 except I H, 210 except I ETS signal, short-circuit to positive or open-circuit

I22 I25 I26

j 25 t 12.0

j 25 t12.0

As of 6/95 129/140 except I H, 210 except I Front to rear axle vehicle speed signal implausible

j 25 t10.0

Engine control module (HFM-SFI) (N3/4)

N3/4

1) 5)

Pay attention to preconditions for test, see j 22. As of 01/94

6)

As of 12/94. On models 140/210 IH fault code 116 may be displayed on vehicles built between 09/95 and 11/95 although there is no fault.

7)

Only possible up to approx. 2/95

cfsdsdds

Diagnosis - Fault memory Possible cause

Remedy/Test step 1)

I27

Actuator ISC and CC/ISC reversed

Replace actuator

I28 I29

Control module HFM-SFI (N3/4)

N3/4

I30

Drive actual value potentiometer

j 25 t 2.0

I3I I32

Control module HFM-SFI (N3/4)

N3/4

I33

Actuator

HFM-SFI control module: teach-in new with HHT. If fault still displayed, replace actuator

I34

Control module HFM-SFI (N3/4)

N3/4

I35

Voltage supply actuator potentiometer

j 25 t 1.0

I36

Drive actual value potentiometer

j 25 t 2.0

I37

Control module HFM-SFI (N3/4)

N3/4

I38

Actuator

HFM-SFI control module: teach-in new with HHT. If fault still displayed, replace actuator

Fault code

N 7)

1) 7)

A

Pay attention to preconditions for test j 22. Only possible up to approx. 2/95

Diagnosis - Fault memory Possible cause

Remedy/Test step 1)

I39

Cruise control tip switch

j 25 t 9.0

I40 I4I I42

Control module HFM-SFI (N3/4)

N3/4

I43

Stop lamp switch

j 25 t 11.0

I44

Control module HFM-SFI (N3/4)

N3/4

Fault code

N 7)

1) 7)

A

Pay attention to preconditions for test j 22. Only possible up to approx. 2/95