Removing and installing anti-theft engine control unit J623 (with locking plate) — VW

Removing and installing anti-theft
engine control unit
J623
(with locking plate)
Note
If you wish to renew the engine control unit, connect the
vehicle diagnostic tester
and perform the guided function
“Renewing engine control unit”
.
DANGER!
For vehicles with heavy duty running gear; vehicle must be restricted to a maximum of 210 km/h via the engine control unit. Drive shafts can be damaged at speeds above 210 km/h. Perform function
“Restricting maximum speed”
in Guided function using Vehicle diagnostic tester.
Special tools and workshop equipment required
Hot air blower from
wiring harness repair set
VAS 1978
Nozzle attachment from
wiring harness repair set
VAS 1978
Grip pliers
Removing:
Switch off ignition.
Remove wiper arms
Electrical system
Rep. gr.
92
Windscreen wiper system; Removing and installing wiper arms
.
Remove plenum chamber cover
General body repairs, exterior
Rep. gr.
64
Flush-bonded windows; Assembly overview - plenum chamber cover
.
Note
The shear-head bolt threads are coated with locking compound. Heating the shear-head bolt with a hot air blower releases the locking effect of the locking compound.
Caution
Cover lines, connections and control units in the vicinity of the engine control unit to prevent damage through heat (scorching/melting of plastics etc.).
Perform settings on hot air blower
4
as shown:
Turn temperature setting potentiometer
2
to maximum heat output (600°C).
Set two-stage switch for volume of air
3
to position 3.
WARNING
When shear-head bolts are heated up, parts of the protective housing will be subjected to a large amount of heat. Wear protective gloves to avoid possible injury.
Place nozzle of hot air blower close to shear-head bolt.
Switch on hot air blower and heat the bolts.
Unscrew shear-head bolt
2
using pliers on bolt head.
The procedure for the second shear-head bolt is exactly the same.
Pull connector
1
off
heated windscreen control unit
J505
.
Lift cover
1
and pull it forwards.
Slide connector locking devices
1
on engine control unit outwards and pull off both connectors.
Remove retainer frame with engine control unit from plenum chamber.
Press locking device
1
outwards and slide engine control unit
2
from retaining frame.
Installing:
Slide engine control unit
1
into retaining frame in direction of arrow.
Fit retainer frame with engine control unit onto retainer in plenum chamber.
Specified torque of securing nuts for retainer: 6 Nm.
Fit connectors to engine control unit and slide locking devices
1
inwards.
Slide cover
1
over engine control unit and press it downwards.
Tighten new shear-head bolts
2
evenly until bolt head shears off.
Fit connector
1
to
heated windscreen control unit
J505
.
Install plenum chamber cover
General body repairs, exterior
Rep. gr.
64
Flush-bonded windows; Assembly overview - plenum chamber cover
.
Install wiper arms
Electrical system
Rep. gr.
92
Windscreen wiper system; Removing and installing wiper arms.