Engine diagnostics.

Switching to initial menu, choose the appropriate group (engine, body, chassis e.t.c.) and appropriate unit from the list. In this example we choose engine control unit MSD80 for N43/N53.

The basic menu allows to identify the unit, read digital and analogue data, activate the units, delete adaptations, perform diagnostic of units.

F1. Menu: SGBD Info contains basic information regarding unit.

F2. Menu – Identification contains detailed technical information regarding unit: HW/SW release data another basic information.

F3. Menu: Anwenden Information – continuation of identification data.

F4. Menu: Error messages: provides the access to error message lists. MSD80 contains three error message lists:

a) actual error message list (Sub-menu: F1);

b) informative error messages – information regarding internal errors of MSD80 (Sub-menu: F2);

c) history error messages or common error message log (Sub-menu: F3).

When choosing actual error message list (Sub-menu: F1), several options of viewing error messages are provided:

a) error message list (Sub-menu: F1): contains information regarding error message code, its transcript (description), error message status (active/passive), information, if this error messages lights up the EML;

b) detailed info or error messages (Sub-menu: F2): additionally displayed – number of error message recordings, odometer value, basic data;

c) freeze frame data (Sub-menu: F3), additionally displayed more detailed information regarding odometer values, when last time the error message has been recorded, characteristics of the engine performance.

Menu of all error message lists (F4).

F4/F1/F1. Example for error message sub-menu (F1).

F4/F1/F2. Example of detailed sub-menu (F2).

F4/F1/F3. Example of freeze frame sub-menu (F3).

Example of History memory log list.

Note: unfortunately, the manufacturer does not gives any information, how often the history list is restored (updated); the error messages, which have been in actual error message list for a short while, may not be displayed in the history error message memory list.

F5. From basic menu. Analogue/digital values.

F5/F1. Sub-menu. Digital values menu.

F5/F1/F1. Sub-menu. Contains information regarding power supply voltage in 15-th bus, accelerator pedal status.

F5/F1/F3. Functional status: basic information regarding performance mode of engine (idle, kick-down), status of all Lambda probes e.t.c.

F5/F1/F4. OBD control menu contains information regarding peripheral units, which performance is being controlled and data sent to OBD for diagnostics.

Continuation of menu.

F5/F1/F5. DME configuration menu.

Continuation of configuration menu.

F5/F2. From basic menu. Menu of analogue data values.

F5/F2/F1. Sub-menu. Module of analogue units No.1.

F5/F2/F2. Sub-menu. Note: parameters of fuel adaptations is recommended to view in appropriate menu (../F5/F6).

F5/F2/F3. Sub-menu. Module of analogue units No.3.

F5/F2/F4. Sub-menu. Values of internal ADC. This menu could be more interesting for MSD80 developers.

Exception: values of throttle and acceleratior pedal sensors. Detailed description here.

F5/F2/F5. Sub-menu.

To control the basic parameters of engine performance, I usually use values, displayed in sub-menu 6 – all actual and more often valuable parameters are displayed here.

F5/F2/F6. Sub-menu. Actual values of menu:

a) all temperature readings are displayed in one menu;

b) two bottom lines – Nernst values of Lambda probes; detailed information read here;

Air consumption in idle (660 RPM): around 18 kg/h Stratified charge (Lambda 2.0); around 12 kg/h Homogeneous mode for warm engine (N53B30);

Note: the engine temperature for N43/N53 in Eco mode can reach 110 .. 115 oC.

If insufficient performance of CO catalytic converter or other significant engine defects are detected, the cooling temperature is decreased below 80 oC, additionally heating up the thermostat (mapped mode). Thermal management of N series, read here;

Pressure of low-pressure pump: 5000 hPa (+/-30 hPa); after switching off the engine it has to stay in 90% level for 10 .. 15 seconds.

Pressure of high-pressure pump: 150’000 .. 200’000 hPa. Detailed information here;

Nernst cell resistance of unheated probes: 16K Ohm and 65K Ohm (accordingly wide-band and narrow-band probes), in working mode: 0/256/512 Ohm; allowed values also: 768/1024 Ohm.

F5/F3. Throttle valve adaptations.

Note: Stratified charge performs only in multiplicative part of adaptations (example below).

Throttle valve adaptations in Homogeneous mode. Both multiplicative and offset adaptations are performing (offset – in idle run, multiplicative – partial/full opening of throttle valve).

Note: Stratified charge and Homogeneous mode have different values of multiplicative adaptations. In case of throttle valve defect, data of both modes have to be checked.

F5/F4. VANOS adaptation menu. Readings of reference value adaptations, required and set values both for intake & exhaust shafts. More about VANOS read here.

F5/F5 IBS/Power management

F5/F6. Fuel mixture adaptations menu. Menu displays:

a) first two lines: PWM values for Lambda probe heating (0 .. 10% initial heating, 30 .. 70% working mode, 95 .. 100% forced heating for faster reach of working mode);

b) integrators for both banks;

c) offset adaptations for both banks (idle);

d) multiplicative adaptations (partial/full load);

e) corrections (momentous) for both banks;

f) Lambda value for wide-band probes.

In the picture: Stratified charge. Both compensations and integrators are 0.0, because the Lambda of Stratified charge fuel mixture is corrected with changing opening of throttle valve (not changing the fuel amount) – values mentioned before are not being used. More about STFT and LTFT here.

F5/F6. Continuation of menu.

g) voltage of wide-band probes (2,0V corresponds Lambda 1.0; 2,5V corresponds Lambda around 2; 3.0V corresponds Lambda around 3.0);

h) voltage of narrow-band probes;

i) repeatedly – multiplicative and adaptive values for both banks.

Fuel mixture adaptations in Homogeneous mode. As you can see, both compensations and integrators are smoothing out the fuel mixture.

Continuation of menu. Homogeneous injection. Appropriate control probe values in case of correct fuel mixture: around 0,7 .. 0,8V.

F5/F7. Rough run menu (mechanical cylinder’s efficiency at idle). Status bit: flywheel adaptation status. Positive bar value: reduced efficiency of cylinder. In case of balanced cylinder performance,  bars for all cylinders has to change polarity (from >0 to <0 and back) after a specific period (typically – not more than 10 seconds). How to perform flywheel adaptations, read here.

Attention: cylinders marked in firing order!

F5/Shift + F1. Energetic model of engine.

F5/Shift + F2. Menu of NOx sensor. More about NOx menu and check-up of NOx sensor performance read here.

F5/Shift + F3. Exhaust ventilation system. Stratified charge, idle: EGR is used to optimize the exhaust gases.

Exhaust ventilation system. Homogeneous injection. As you see, EGR is closed (to ensure stability of idle and fuel mixture composition).

F5/Shift + F5. Adaptation maps. Unfortunately, most part of them is not displayed, even when using loader 2.023.

F5/Shift + F6. Individual adaptation data for injectors.

F5/Shift + F6/F1. Sub-menu: real time data of injectors;

a) opening time;

b) applied relative correction;

c) electric charge.

Continuation of menu:

d) voltage;

e) energetic charge.

F5/Shift + F6/F2. Sub-menu: status bits. Points out individual adaptation modes for injectors.

Status after completed individual adaptations:





Note: MSD80 regularly performs re-adaptation of injectors, it’s possible (*) status bit change:


*; ON

*; *

*; *

In case of status bit (mode) change, MSD80 switches from Stratified to Homogeneous injection. Additionally – MSD80 switches to Homogeneous injection mode also in other cases, for example: performing the re-calibration of multiplicative or offset values for banks, balancing the mechanical efficiency of cylinders in idle, calibrating wide-band Lambda probes e.t.c.

F5/Shift + F6/F3. Sub-menu: measurements of efficiency of injectors for low/high load at Homogeneous mode:

a) results of last test;

b) efficiency measurements for cold engine (always 0, obviously – additional corrections are applied only within banks, see F4 Sub-menu).

Continuation of menu:

c) applied corrections for long injector opening;

d) applied corrections for short injector opening.

F5/Shift + F6/F4. Sub-menu: additional corrections of banks for cold engine, starting from -20 oC to +90 oC. Maximum depth of corrections +/-8%. For the latest software releases: allways 0 (obviously – average value added to each bank’s adaptations).

F5/Shift + F6/F5. Sub-menu: additional corrections of injectors in idle for Stratified charge:

a) results of last test.

Continuation of menu:

b) applied multiplicative multiplier after results of last test.

To be continued.


Related entries:

Diagnostics with INPA. Part 4

Diagnostics with INPA. Part 3

Diagnostics with INPA. Part 1