SEAT Workshop Service and Repair Manuals

Engine control unit with anti-theft protection II: Removing and installing Special tools and workshop equipment required

t  Vehicle diagnostic, testing and information system -VAS 5051B- or vehicle diagnostic and service information system -VAS 5052-

t  Hot-air gun -1- (from the wire repair set -VAS 1978B-), see equivalent t  Connectable nozzle -2- (also from the cable repair kit -VAS 1978A-) t  Self-locking pliers, sold commercially (gripping jaws) -3-   Note t  To replace the engine control unit, connect the central diagnosis and complete the guided function „Replace engine control unit“. t  The thread on the breakaway bolts can been treated with a threadlocker. For making sure that unscrewing is easier, you can warm the head screws using the Hot air blower -VAS 1978/14-. Ensure that neither the lines or connectors nor components in the vicinity are damaged. Removal: –  Switch ignition OFF.

–  Pull off rubber seal -2- on plenum chamber cover.

–  Remove bolts -1-.

–  Remove parting wall for plenum chamber.   Note

t  The engine control unit -1- is bolted to a protective casing -2 and 5-. To make it even more difficult to undo the breakaway bolts -3 and 4- on the locking device-2-, a threadlocker has been used. t  To disconnect connectors on the engine control unit (e.g. when connecting the testing box or to replace the engine control unit), the protective casing must be removed. –  When renewing engine control unit, select diagnosis object „engine control unit“ in Guided Functions„: replace. “ → Vehicle diagnostic, testing and information system VAS 5051

–  Open the clip»arrow« and remove the engine control unit.   WARNING To ensure that damage (burning) is not caused to the cables and connectors as well as insulation and control units, the following steps must be observed in all cases: Remember the instructions for using the hot-air gun. Carry out the adjustments on the hot air blower -4- as described below:

–  Turn temperature setting potentiometer -2- to maximum heat output (600 °C).   Note t  Next, heat the breakaway bolts with the hot-air gun. This reduces the strength of the threadlocker on the thread of the breakaway bolts to make them easier to remove. t  Cover all painted parts to prevent damage from the hot-air gun or the self-locking pliers.   WARNING When breakaway bolts are heated, some parts of the protective casing become very hot. Risk of burn injuries! Also, make sure that, as far as possible, you only heat the breakaway bolt and not adjoining parts. If necessary, cover these parts.

–  Bring the nozzle of the hot-air gun up to the breakaway bolt on the lock. –  Connect hot air gun and heat the head bolt approx. 20 to 25 seconds.

–  Release the breakaway bolts with the self-locking pliers -arrow-. Follow the same procedure with the second breakaway bolt. Separate the protective casing from the engine control unit. –  Unlock the front and rear connectors from the engine control unit.

Fitting . Installation is carried out in the reverse order. When installing, note the following: –  Remove the remains of the threadlocker from the breakaway bolt holes. A male thread tap can be used for this. –  First connect the rear connector and next, the front connector to the engine control unit and lock. –  It is essential that the protective casing -2 and 5- is replaced onto the engine control unit. –  Use new breakaway bolts. –  Interrogate and erase fault memory if necessary → Chapter.