ME-SFI diagnosis fault memory function - GF07.61-P-2004GS

ENGINE 111.951 in MODEL 203.035

ENGINE 111.952 in MODEL 202.081

ENGINE 111.955 in MODEL 203.045

ENGINE 111.956 in MODEL 202.087, 208.344 /444

ENGINE 111.957 in MODEL 210.048 /248

ENGINE 111.958 in MODEL 170.444

ENGINE 111.981 in MODEL 203.747

ENGINE 111.982 in MODEL 208.448

ENGINE 111.983 in MODEL 170.449

Fig 1: ME-SFI Diagnosis Fault Memory Function Diagram - Engine 111.955 In Model 203.045 And Engine 111.981 In Model 203.747

The ME-SFI control module checks its inputs and outputs for plausibility and detects possible faults. The recognition of faults and their storage is differentiated as follows:

Fault constantly present

Loose contact faults (only in the case of coolant temperature and pedal value sensor)

The fault memory is not erased if the vehicle battery is disconnected.

Reading out fault memory

The faults stored can only be read out and erased at the data link connector with ignition "ON" or with "engine running" using the STAR DIAGNOSIS.

In line with legal requirements, faults can also be read out at the diagnosis test connector conforming to SAE standard, ISO 9141-2, with generic scan tool.

Fault recognition

Signals above or below limit value (open circuit in wiring, short circuit, sensors faulty)
Frequency with fault freeze frame data
Illogical combination of signals
Function chains with fault
Fault messages over CAN databus from ETC, ESP or RFL/EIS/IC/ESM control module

Fault storage

Faults detected are written to the fault memory as a fault together with freeze frame data. If the fault is not confirmed in the subsequent driving-cycle, it is erased. Emission-relevant faults are always entered, they have a high priority. Non exhaust-relevant faults are erased if there are more than 5 entries.

Actuation of the CHECK ENGINE malfunction indicator lamp

Actuation of the engine diagnosis malfunction indicator lamp (in the case of low-emission EURO3/4)

The malfunction indicator lamp in the instrument cluster comes on if the fault was already stored in the last driving cycle .

A driving cycle for a test consists of

Engine start
particular test performed
engine switched off

Fault freeze frame data/operating conditions

If a fault is detected, the following data are stored:

Fault code
Vehicle speed
Engine speed
Coolant temperature
Intake air temperature
Intake manifold
Intake manifold pressure
Engine load status
Throttle valve angle
Ignition angle
Gear engaged (MT, AT, ESQ)
Mixture formation adaptation value
Status of lambda control
- Lambda control not enabled
- Lambda control enabled
- Lambda control disabled (e. g. in the case of fuel shutoff)
- Lambda control disabled (e. g. if fault detected)
- Lambda control without correction of O₂ sensor downstream of TWC
Further fault freeze frame conditions (e.g. fuel tank level, time after end of start, distance in the case of fault entry, counter readings for fault frequency, purging or secondary air injection active, emergency mode active)

Function chains are test sequences, e.g. for secondary air injection, purge system and leak-tightness of evaporative emission control system, activated by the ME-SFI control module.

Consequential faults

If a faulty signal is detected and the corresponding fault code is stored, all the tests in which the signal is required as a comparative parameter, are ended. This serves to ensure that consequential faults parameter, are ended. This serves to ensure that consequential faults are not stored.

Limp-home mode

If a fault is detected, substitute values are formed. The malfunction indicator lamp in the instrument cluster comes on if the fault was already stored in the last driving cycle .

Readiness/function code

This code makes it possible to recognize that tests relating to fault recognition are in progress and the system is thus active.

The code is set once the following tests are completed (result of test not significant):

Catalytic converter efficiency
Purge control
Secondary air injection
O₂ sensor upstream of TWC, signal
O₂ sensor upstream of TWC, sensor heater

Fig 2: MIL Lights Flow Chart

ME-SFI control module position/task/ design/function		GF07.61-P-5000GS
Pressure sensor, location/design/task/function		GF07.04-P-5014F
CHECK ENGINE malfunction indicator lamp location/task/function		GF07.13-P-3144F
Engine diagnosis malfunction indicator lamp, location/task/function	low emission EURO 3/4 (code 925)	GF54.30-P-4102A
Connect STAR DIAGNOSIS and read out fault memory		AD00.00-P-2000-04A
ME-SFI fuel injection and ignition system, DTC memory	Fault codes List of all P-codes with possible causes of faults and references to remedy.	AD07.61-P-4000GS