Removing and installing engine control unit J623 with protective housing, Sharan and Tiguan — VW

Removing and installing
engine control unit
J623
with protective housing, Sharan and Tiguan
Special tools and workshop equipment required
Hot air blower
VAS 1978/14A
item 1
with nozzle
2
from
wiring harness repair set
VAS 1978 B
Vehicle diagnostic tester
Note
If the engine control unit is to be replaced, connect the
vehicle diagnostic tester
and carry out the guided function
“Renewing engine control unit”
.
The shear-head bolt threads may coated with locking compound. To simplify removing, the shear-head bolts can be heated using
hot air blower
VAS 1978/14
. When doing this, ensure that no adjacent cables, connectors or components are damaged!
Removing
If the engine control unit is to be renewed, switch on ignition, and select the following menu options on
vehicle diagnostic tester
:
01 - Engine electronics
Guided functions
01 - Renew engine control unit
Switch off ignition and remove ignition key.
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.
50
Plenum chamber cover
.
Remove plenum chamber bulkhead
General body repairs, exterior
Rep. gr.
50
Plenum chamber bulkhead
.
Pull seal together with engine wiring harness upwards in
direction of arrow
out of cable guide.
If fitted, unclip cover
1
at sides from mountings
1
arrows
, and remove it.
Push guides
2
towards side.
Remove engine control unit
1
upwards.
Bend upwardly projecting tabs
1
of locking bar outwards.
Make groove (for a screwdriver) in head of shear bolt
1
using a small grinder
2
.
Note
The threads of the shear bolts are secured with locking fluid. To unscrew these bolts, the threads must therefore be heated with the hot air blower.
Set hot air blower as shown in illustration.
Potentiometer for temperature adjustment
2
set to maximum heat output.
Two-stage switch for air flow rate
3
set to position 3.
Note
Risk of damage to adjacent components caused by hot air blower. Risk of overheating.
If necessary, cover adjacent components.
Heat head of shear bolt
1
for approx. 20 to 30 seconds.
Unscrew shear bolt
1
using screwdriver
2
.
Slide connector locking devices
1
on engine control unit in
direction of arrow
and pull off both connectors.
Installing:
Attach connectors to engine control unit and slide locking devices inwards until they engage.
Screw on a new locking bar
3
with new shear-head bolts
2
and tighten bolts uniformly until just before heads shear off.
Disregard item
1
.
Push engine control unit
1
into side guides
2
in the
direction of arrow
.
Install plenum chamber bulkhead
General body repairs, exterior
Rep. gr.
50
Plenum chamber bulkhead
.
Install plenum chamber cover
General body repairs, exterior
Rep. gr.
50
Plenum chamber cover
.
Fit wiper arms
Electrical system
Rep. gr.
92
Windscreen wiper system; Removing and installing wiper arms
.