BMW 5 series E39

Since 1996-2001 of release

Repair and car operation

The description of system of onboard diagnostics

(In case of the equipment of your car OBD II on шильде under a cowl should be record “OBD II compliant” and there should be a 16-contact socket. As a rule, OBD II North American models, since 1996 of release and the European models, since 2000 of release) are equipped

System OBD structure includes some the diagnostic devices making monitoring of separate parametres of systems of decrease of toxicity and fixing revealed refusals in memory of the onboard processor in the form of individual codes of malfunctions. The system makes also check of gauges and actuation mechanisms, supervises vehicle service cycles, provides storing possibility even failures quickly arising in the course of work and clearing of the block of memory.

Models described in the present Management are equipped by system of onboard diagnostics. A system basic element is the onboard processor, more often named the electronic module of management (ЕСМ), or the module of management of functioning of the power unit (РСМ). РСМ is a brain of a control system of the engine. The initial data arrives on the module from various information gauges and other electronic components (switches, the relay etc.) . On the basis of the analysis of the data arriving from information gauges, and according to put in memory of the processor in base parametres, РСМ develops commands on operation of various operating relays and actuation mechanisms, carrying out thereby updating of working parametres of the engine and providing peak efficiency of its return at the minimum expense of fuel. Data read-out of memory of the processor is made by means of the special scanner connected to a 16-contact diagnostic socket of reading of a database (DLC), located on the average console or to a 20-contact diagnostic socket located at the left in an impellent compartment.

On service of components of control systems by the engine/decrease of toxicity of the fulfilled gases special guarantee certificates with the prolonged period of validity extend. It is not necessary to undertake attempts of independent performance of problem diagnostics РСМ or replacement of components of system, to an exit of terms of the given obligations, - address to experts of firm car repair shops.

Reading of codes of malfunctions

Codes DME (SAE J1979) are transferred by a 8-digit binary word (byte). Each category (bit) reflects result of check of a certain electric chain of a control system, and accepts value 0 - if the test has passed, and 1 - if malfunction is found out.

Example of information byte and value of its categories

The information maintenance of categories of 5-digit code SAE

Kind P 0 3 8 0 at the left-to the right:

1 category
   -   P the power unit
   -   B a body
   -   From the chassis
2 category a code Source
   -   0 standard SAE
   -   1 set BMW
3 category System
   -   0 system as a whole
   -   1 подмешивания air (air/fuel induction)
   -   2 injections of fuel
   -   3 systems of ignition or ignition admissions
   -   4 additional control of release
   -   5 speeds of the car and management х.х.
   -   6 entrance and target signals of the block of management
   -   7 transmission
4,5 categories the Serial number of malfunction of a component or a chain (00-99)

Appointment of conclusions of a 20-contact diagnostic socket

Reading of codes of malfunctions

At revealing of the malfunction repeating successively on two trips, РСМ gives out a command on inclusion of the control lamp built in in an instrument guard “Check up the engine”, named also the indicator of refusals. The lamp will continue to burn until memory of system of self-diagnostics will not be cleared of the codes of the revealed malfunctions brought in it. Reading of codes of malfunctions in system OBD can be made by means of described above the devices connected to a diagnostic socket. Other ways are possible not on all models. The blinking code can be считан on a lamp “Check up the engine”.