Notes Regarding Plug Connections - AH00.19-P-1000-06A
Model All (4xWD, CAR, Light transporter, smart)
Terminology of electrical connections:
Coupling and plug form an electrical connection. The female contact and the contact pin form the contact pair.
Shown on SLK family, coding A (with circular conductor)
Plugs and couplings
The plugs and couplings are grouped into families in the same way as the contact groups (e.g. SLK, JPT). The type and shape of the receptacle chambers in the housing is the major differentiating characteristic. Different contact families may be installed in the same housing. Different codings (e.g. A, B, C) may also exist within the same plug/coupling family.
Codings are special profiles or teeth on the housings of the coupling and the plug, which may be marked in different colors (e.g. black, white, violet).
These ensure that connector pairings can only be made with the same codings.
- Safety and restraint systems (airbag, emergency tensioning retractor, roll bar) have yellow, orange, or red electrical connections for easy identification.
Part number assignments
The housings are assigned according to the part numbers on the housings. On housings made up of several components, the number on the external housing is critical. (When ordering, all the individual part numbers must be ascertained).
This method of identification by means of part numbers can be used when referring to the literature.
Contacts
A distinction is made between the contact pin and the female contact. Each contact pin and each female contact can be clearly assigned to one group or "family" (e.g. SLK, JPT). Within these families distinctions are made according to the cable cross section and whether there is single-strand insulation for watertight connections. The contacts are also distinguished by their coating (tin, gold or silver).
The contacts are fastened to the cables by means of crimping.
Crimp connections
Crimped connections are used to connect female contacts or contact pins to the line. Each contact type must be crimped with the aid of specifically assigned matrixes using a pair of pliers. Determining factors: contact family, size of cable cross section, with or without single-strand insulation.
Only lines up to 4 mm2
may be crimped.
Unpinning
This requires a release tool appropriate to the contact family in order to remove female contacts and contact pins from plugs and couplings.
On some plugs and couplings the housings must first be disassembled and unlocked (secondary release) according to the instructions before the actual unpinning.
Contact materials
The contacts used in the interior of the vehicle are primarily tin/tin combinations. Those used on the exterior and in the splash zone are generally silver/silver combinations. Safety systems (particularly the airbag) are equipped with gold/gold combinations.
"Similar" contact pairs with the same contact surface (coating) are required for the repair.
Differentiation and special features for safety-relevant electrical connections
A differentiation is made into the two following types of connection for electrical connections on safety-relevant systems, components or connections at risk to short circuits:
- Positive connection
- Non-positive connection
Positive connection
The electrical connection is latched into place, e.g. when connected through catch hooks, slides, clips, threaded connection or suchlike, and they can only be disconnected from the connected equipment again by operating a release or by unfastening the bolted connection. They cannot be disconnected by simply pulling on the connector housing under normal control forces.
A positive connection is checked using the "Push-Pull-Push" method (except for bolted connections).
Non-positive connection
The electrical connection does not latch into place when connected, but it is simply clamped, for example, using a toggle-action clamp. Pulling on the electrical line or the electrical connection can disconnect the electrical connection.
A positive connection is checked using the "Push-Pull-Push" method.
In the "Push-Push" or "Push-Pull-Push" test, the line should not be tugged or pressed together. The electrical connection must be directly engaged. Otherwise, damage may occur or there may be contact problems with the electrical connection.