Bosch ME7.1.1

This section is underdevelopment. Feel free to add content.

Reading, writing and checksums

For reading and writing procedures refer to Reading and writing ECU (ME7.1.1)

Most flashing tools fix checksums automatically, if you wish to fix them manually, you can use LSuite

Definition file can be found here. If you are getting started with tuning with recommend consulting : Introduction to tuning

Terminology (Acronyms)

Maps and variables names are identified under acronyms. Knowing some of them will be useful and will help you remember map names.

Here is a list of the useful ones.

List of acronyms

Acronym	German	English
A	Auslaßnockenwelle aktiv	Exhaust camshaft active
AB	Abregelfaktor	Derating factor for acceleration signal
AL	Adaptation Lastbereich	Adaptation load range
ASR		Anti-slip regulation
BB	Betriebsbedingungen	Operating conditions
BG	Berechnete Große	Calculated variable
BTS	Bauteilschutz	Component protection
CW		Code word
DFPM	Diagnose-Fehlerpad-Managers	Diagnostic Faulth Path Manager
DK	Drosselklappe	Throttle valve
DS-S		Pressure sensor (MAP) on intake manifold
E	Ersatzwert	Substitute value
ESUK	Einspritzung Ubergang Kompensation	Injection transition compensation
FA	Fahrer	Driver
FGR	FahrgeschwindigKeitsregler	Cruise control
FK	Faktor	Factor
FUEREG	Fullungreglers	Filling regulators
HFM		Hot film air mass sensor
KF	Kennfeld	Map
KL	Kennlinie	Curve
KN	Klopfereignis	Knock event
KR	Klopfregelung	Knock control
KRA	KR-adaptation	KR-Adaptation
KUPPL	Kupplung	Clutch
KW	Kurbelvelle Grad	Crankshaft degrees
LL	Leerlauf	Idle
LLK	Leerlauf und geoffneter kupplung	Idle and open clutch
LLRBB	Leerlaufregelung Betriebs dedingungen	Idle control operating conditions
LU	Laufunruche	Unstediness / roughness
LUAR	Laufunruhe-Abstandsmass-Referenzwert	Rough running distance measure value
LUR	Laufunruche-Referenzwert	Rough running reference value
MBVH	Missbrauchverginderung	Abuse prevention
MI	Motormoment indiziertes	Indicated torque
ML	Motor Luftmassendurchsatz	Engine air mass flow
MN		Minimum
MS	Massenstrom	Mass flow
MX		Maximum
N	Normierter	Normalized / NM
NW	Nockenwellen	Camshafts
NWS	Nockenwellengsteverrung	Camshaft control
OP	Optimales	Optimal
PVD	Pressure vor Drosselklappe	Pressure in front of DK
RL	relative Luft	Relative air filling (load)
RLMIN	Relative mimale Luft	Relative minimal air (filling)
SA	Schubabschatten	Fuel cut-off / overrun
SOL	Soll	Should
SW	Schlechtwegstrecke	Rough road
TPKHFM	TemperaturKorrektur HFM	Temperature correction HFM
TUM	Umgebungstemperator	Ambient temperature
TV		Delay time
UGD	Ungedroselt	Unthrottled
V	Verzogert	Delayed
WDK	DK-Winkel	DK angle
WKR	Winkelspatverstellung	Angle retard KR
WL	Warmlauf	Warm up
ZUL	Zulassig	Allowed limit
ZW	Zundungs Winkel	Ignition angle

Engine management

The ME7.1.1 use a ST10F275 micro-controller. This set it apart from most ME7 ecus that use the Infineon C167_SR.

There are no public funktionsrahmen for the ME7.1.1. You will have to refer to the following funktionsrahmen : ME7.5 Funktionsrahmen, MED9.1 Funktionsrahmen and MED17.5 Funktionsrahmen

For the fuel injection and knock control system, you can refer to ME7.5 / MED9.1 FR.

Intake manifold pressure schemes are will be found on the MED17.5 FR.

Most other modules will be based on the MED9.1 architecture.

This ecu is load-dependent. Most map works with the requested load or the actual load.

Air mass

HFM (Aka MAF)

HFM5

The ME7.1.1 use a Bosch HFM5 sensor.

The HFM5 return an analog voltage signal to the ECU. The ECU use this sampled voltage value in the MSHFMU map to determine the air mass flow.

Over time voltage drop can happen in the signal wire, this will influence the measured value. For this reason, Bosch switched from a sampled voltage measurement to a sampled period measurement. Sampled period measurement is covered in HFM6.

For more information regarding the HFM5 sensor, refer to HFM5.pdf

HFM6

The HFM6 is not used on ME7.1.1, but I believe covering this sensor is pertinent and interesting.

The HFM6 use a similar design to the HFM5. The bypass channel is flow-optimized compared to the HFM5.

The HFM6 transmit a digital signal for the measured air mass. The air mass measurement is evaluated by the frequency (period) instead of the signal voltage.

The advantage of using a digital signal is that voltage drop / interference does not influence the measurement, which make it more reliable than the HFM5. If the HFM fails, the ECU will use a substitute air-mass model stored in the ECU, like the BGMSDK module (Calculation from throttle angle)

For more information regarding the HFM6 sensor, refer to HFM6.pdf (this is a great document to get a better grasp of HFM)

Reverse flow / pulsations

On some conditions (like intake valve closing, for example), the air might go back through the HFM and influence the readings. Different displacement elements can influence pulsation. To correct these pulsations, the ECU will rely on pulsation map : KFPU, KFPUKL1

The ECU will select a specific pulsation map depending on which elements are influencing pulsations. When using an aftermarket MAF, if you do not wish to deal with those maps, you can set the pulsation maps to 1.0 to disable the pulsation compensations. It should not have much incidence on the engine safety. Please keep in mind that while the engine is on "boost", the HFM is not affected by reverse flow or pulsations. The pulsation compensations are in place to ensure an accurate air mass reading at all-time which lead to more control for stoichiometric AFR thus resulting in better emissions.

BGMSDK (Calculation from throttle valve angle)

This module calculate an air mass flow based of the throttle valve angle, a pressure ratio (intake manifold pressure / the pressure before the throttle valve) and the gas temperature (since it affects air density)

The map KFMSNWDKVP stores the air mass flow depending of the opening angle and the pressure ratio according to the following standards:

• Pressure in front of throttle valve (before) = 1013 hPa
• Gas temperature = 0°C

A pressure and a temperature correction factor is applied to to the standardized mass air flow (Respectively, ftvdk and fpvdk).

*Gas velocity is equal to the speed of sound under a pressure ratio of 0.528

Interesting to note the temperature correction factor (ftvdk) formula:

273 Kelvin = 0°C

${\sqrt {(273Kelvin\;/\;intake\;air\;temperature\;(to\;Kelvin))}}$

For the pressure ratio (fpvdk), it would be as simple as :

$Pressure\;in\;front\;of\;throttle\;/\;1013\;hPa$

Fuel injection

ESUK (Transient compensations)

This module adjusts the injection for transient conditions. The map WFRL contains the amount of fuel that is stored stationary in the wall-film (fuel puddle) at the respective load (pressure).

When the load (pressure) change, the difference in the fuel quantity of the wall-film (fuel puddle) is calculated to ensure the correct air/fuel mixture on transient condition.

Transient condition

Transient conditions are triggered by acceleration / deceleration. (Any drastic change in manifold pressure)

The transient condition cause a change of pressure that makes the engine run leaner / richer for a short moment until equilibrium is reached again.

Some of the injected fuel forms a fuel film (puddle) on the port. On a steady engine, the fuel film (puddle) evaporate at a constant rate, making it possible to achieve our desired AFR.

On acceleration, the pressure increase. This increased pressure force against the fuel molecules that are trying to evaporate from the fuel film (puddle). This slows the rate of evaporation momentary, making the AFR leaner for that moment. (Remember the engine burn the vapors).

On deceleration, the pressure decrease. The decreased pressure make it easier for the fuel molecules to evaporate. The rate of evaporation is faster momentary, causing the AFR to be richer.

Controlling the AFR

With LAMFA

The LAMFA map stores the desired lambda (λ / AFR ratio relative to the stoichiometric ratio) according to the engine (nmot) and the relative desired torque from the FGR (cruise control) and the accelerator pedal (mrfa_w).

The inconvenience with controlling the AFR with this map is that the map does not use the actual load, but the "desired" load. This means that the engine could be on a low load and the driver could request a high loader that would set the AFR really rich on a low load engine, since the AFR is dependent on the driver wish (desired load) and not the current engine load (rl)

With KFLBTS

The KFLBTS map define which AFR ratio to use when the component protection mode (BTS) is active.

This map has a high resolution that allow to be very precise on multiple engine conditions (load and engine speed).

We can force the engine to go into BTS to use this map at all time to control AFR. One downside of using this method is that we loose one OEM safety feature. It is important to understand why this map exist in the first place. The ECU should use this map to affect the air-mixture only if one component (such as catalytic converter, exhaust gas) reach a temperature threshold. The purpose is to increase the fuel delivery to cool down the components.

Forcing BTS

Set the following threshold to 0 : TKATBTS AND TABGBTS

You can set ZLBTS and ZLBTSDLMX higher if you want to smooth out the enrichment (refer to page 2579 of the MED9.1 FR)

Accelerator pedal

*The driver does not request a throttle angle, but a desired relative torque

KFPED : Relative driver desired torque from accelerator pedal

KFPEDL : Relative torque desired at low speed

KFPEDR : Relative torque desired in reverse gear

Idle speed

NLLMG : Target speed for idle steady-state

NLLMGFS : Target speed when set

KFNLLNST : RPM curve after start

Limiters

Engine speed

NMAX : Engine speed limitation

NMAXFA : Increased speed limit for function request (workshop test)

NMAXGA : Maximum allowable engine speed (stationnary)

NMAXOGGA : Maximum permissible engine speed (temporary increase)

NMXBENOT : Maximum speed with gearbox emergency operation

NMAXTMM : RPM limitation at high engine temperature

NMAXTO : RPM limitation at high oil temperature

NMAXDVG : Speed limit for automatic transmission in the event of speed failure

• Set those maps to the RPM limit you wish (for example 7500rpm)

You can also adjust those map if you want to.

NDNWMX : Maximum speed for camshaft control diagnosis

NNWMX : Max. threshold for switching off the NW adjustement

• Set them over your RPM limit

NMINMBVH : Minimum engine speed to activate the MBVH anti-misuse system

• Set higher than your RPM limit to desactive this system

Vehicule speed

VMAXESP : Maximum permissible speed in the event of ESP failure

VMAXNB : Maximum permissible speed in normal operation

• Max them out (FF FF) to disable the vehicule speed limiter

Brake boost

WPMXBR : Maximum permissible pedal value when brake is actuated

• Max out (FF FF)

Disabling DTC

The DTC are stored under error class that are defined in a "DTC table". The index at which a certain error class/DTC is stored in the DTC table can be calculated with a simple formula.

Before getting started, you should define the following address that you will use for calculations:

• CDC (CARB codes, OBD2 generic) start address : CDCAAA
• CDK (Kundle (Customer) / Manufacturers codes) : CDKAAA
• CLA (Error class aka DTC table) : CLAAAA

You can use the .A2L file that match your ECU:

In this case the CDC start address would be 0xE59C2. (The offset of 0x800000 has been substracted from the address)

Once the start address are defined, we can proceed to the calculation of the DTC index.

For generic codes (Starts with P0XXX):

We will use the table CDC

For manufacturer code:

We will use the table CDK

Finding the index

Let's assume we want to remove the code P0302, this is a generic code, so we will be using the table CDC.

In WinOLS (or your map editor of choice), set the view in 16bits, FF, LoHi

Go to (Control-G) the start address of CDC, in this example it would be 0xE59C2

Search for an hexadecimal (using Control-F) with the DTC code : 0302

You should see 0302 repeating 4 times, we want the address of the first occurence of the block of 4. If you see a block of 6, ignore the first two occurences.

The address of the first occurence of 0302 would be 0xE5DE2.

Now to get the index we use this formula :

Index = (address of the first occurence - start address of the table) / 8

In our example it would be :

(0xE5DE2 - 0xE59C2) / 8 = 0x84

Index is 0x84

Locating the error class in the CLA table

Using the start address provided by CLAAAA, use the following formula:

CLA error class address = CLA start address (CLAAAA) + index

In our example it would be :

CLA error class address = 0xE05B1 + 0x84 = 0xE0635

The address 0xE0635 contains the error class for the DTC P0302.

To disable the DTC set the byte at the address 0xE0635 to 0.