Removing and installing anti-theft-secured engine control unit J623 (►model year 2007) — VW

Removing and installing anti-theft-secured
engine control unit
J623
(►model year 2007)
Special tools and workshop equipment required
Hot air blower from
wiring harness repair set
VAS 1978
Nozzle from
wiring harness repair set
VAS 1978
If you wish to renew the engine control unit, connect the
Vehicle diagnostic tester
and carry out the guided function
“Renew control unit”
.
Removing
Remove windscreen wiper arms and cover for plenum chamber
Electrical system
Rep. gr.
92
Removing and installing windscreen wipe system
.
Remove air filter (engine code BMD)
Chapter
.
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 brake hose and cable to brake fluid container in order to avoid damage.
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 bolt for about 20 to 25 seconds.
Unscrew shear-head bolt using
mole grips
on bolt head.
The procedure for the second shear-head bolt is identical.
Push the clips of the protective housing in the plenum chamber together and unhook it from the plenum chamber bulkhead.
Pull the protective housing off the engine control unit.
Release connectors on engine control unit and pull off connector.
Installing
Fit connectors and lock in position.
Push the protective housing over the engine control unit.
Install cover of protective housing using new shear-head bolts.
Tighten shear-head bolts evenly until head shears off.
Hook the protective housing into the plenum chamber bulkhead and push the clips into the openings.
Install windscreen wiper arms and cover for plenum chamber:
Electrical system
Rep. gr.
92
Removing and installing windscreen wipe system
.
Install air filter (engine code BMD)
Chapter
.
If
engine control unit
J623
is renewed, erase learnt values and adapt engine control unit
Vehicle diagnostic tester
“Guided functions”
.
Read fault memory, rectify any faults and then erase fault memory
Vehicle diagnostic tester
“Guided fault finding”
.
The readiness code must be generated if the fault memory has been erased.
Carry out a road test.
Read control unit fault memory again.