Volkswagen Golf Service & Repair Manual: Removing and installing engine control unit -J623- (with protective housing)
| Special tools and workshop equipment
required |
|
|
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| Hot air blower -VAS 1978/14A--item 1-
with nozzle -2- from wiring harness
repair set -VAS 1978 B- |
| Small grinder (commercially available) |
| Vehicle diagnostic tester |
| – |
If engine control unit is renewed, select test
sequence/function Replace engine control unit on “vehicle
diagnostic tester” in “Guided functions” mode. |
| – |
Switch off ignition and remove ignition key. |
 Note
|
t |
If the engine control unit comes into contact with the
positive battery terminal, the engine control unit will be
destroyed. |
| Therefore, the battery must be disconnected before the
engine control unit is removed
→ Electrical system; Rep. gr.27. |
|
|
|
| To remove protective housing -1-,
unscrew shear bolts -arrows- as
follows: |
Note
| Cover the area around the engine control unit, and protect
it from flying sparks. |
|
|
|
| – |
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. |
| – |
Select settings on hot air blower as shown in illustration,
i.e. set temperature potentiometer -2-
to maximum heat output and two-stage air flow switch
-3- to position 3. |
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-. |
|
|
|
| – |
Release fastener -arrow- and
detach engine control unit -1-. |
| – |
Release and unplug connectors for engine control unit
-J623-. |
| Installation is carried out in the reverse order; note the
following: |
| – |
It is essential that the engine control unit -J623- be
provided with the protective housing again. |
| – |
Remove any locking compound residues from the threaded holes
for the shear-head bolts. Threads can be cleaned using a tap
(thread cutter). |
| – |
Use new shear-head bolts. |
| After having installed the new engine control unit, the
following work must be carried out: |
| – |
Connect battery
→ Electrical system; Rep. gr.27. |
| – |
Connect vehicle diagnostic tester. |
| – |
Switch on ignition and select the following menu options on
vehicle diagnostic tester: |
| 01 - Renew engine control unit |
|
|
|
Special tools and workshop equipment
required
Hot air blower -VAS 1978/14A--1-
with nozzle -2- fr ...
Other materials:
Refrigerant pressure and temperature sender -G395
WARNING
Danger of freezing injuries.
If refrigerant circuit has not been evacuated,
refrigerant will escape.
The refrigerant must be extracted before removi ...
Warning lamp
First read and observe the introductory information
and safety warnings
Lit up
Possible cause
Solution
Fault in the alternator.
Proceed to a qualified workshop. The electrical system
should be checked.
Switch off all elec ...
Assembly overview - front brakes
Note
After every brake pad change, depress brake pedal firmly
several times with vehicle stationary, so that brake pads are
properly seated in their normal operating position.
Use the brake filling and bleeding equip ...
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Removing and installing engine control unit -J623- (with metal locking
plate)
Exhaus system