Renewing Simos control unit J361: Audi 2.4 (BDW)

Renewing
Simos control unit
J361
Note
When the engine control unit is disconnected, the learnt values are erased but the contents of the fault memory remain intact.
Special tools and workshop equipment required
Hot air blower (220 V/ 50 Hz)
VAS 1978/14
item 1
with nozzle attachment
2
from
wiring harness repair set
VAS 1978
Small, commercially available vice grip pliers
3
WARNING
Heating the thread of the locking plate also heats up the shear bolts and parts of the metal housing. Take care to avoid burns. It is also important to ensure that only the thread is heated and none of the surrounding components if at all possible. These should be covered if necessary.
Removing
Simos control unit
J361
Connect
vehicle diagnostic, testing and information system
VAS 5051B
and select vehicle system
“01 - Engine electronics”
from list. When doing this, the ignition must be switched on.
Always start by displaying the control unit identification and printing it out.
Switch off ignition and remove ignition key.
Pull off rubber seal
1
on plenum chamber cover.
Detach plenum chamber cover
2
.
Use screwdriver to pry off cover caps on wiper arms and unscrew hexagon nuts.
Pull wiper arms off wiper shafts.
Unscrew bolts (left and right)
arrows
from cowl panel
1
.
Unscrew bolts
arrows
and take off cover for electronics box.
WARNING
The pump valve unit for the heating system (left in front of electronics box) gets very hot – risk of burns!
Carefully lever out the retaining strap
3
using a screwdriver
arrows 1 and 2
and remove the engine control unit from the electronics box.
To help prevent unauthorised access to the connectors on the engine control unit, the engine control unit
1
is bolted to a metal casing
5
by means of shear bolts
3 and 4
and a locking plate
2
.
The threads of the two shear bolts
4
which are not screwed into the engine control unit are secured with locking fluid. To unscrew these two bolts, the threads must therefore be heated with the hot air blower.
The threads of the two shear bolts
3
which are screwed into the engine control unit are not secured with locking fluid. Do not apply heat to the threads in the control unit housing; this is not necessary and would cause overheating of the control unit.
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.
WARNING
Heating the thread of the locking plate also heats up the shear bolts and parts of the metal housing. Take care to avoid burns. It is also important to ensure that only the thread is heated and none of the surrounding components if at all possible. These should be covered if necessary.
Apply heat to the threads of the shear bolts on the connector side as shown in the illustration.
Switch on the hot air blower and heat the bolt for approximately 20 ... 30 seconds.
Unscrew shear bolts using vice-grip pliers (see arrow in illustration).
The two shear bolts screwed into the control unit do not need to be heated. They can be removed without heating.
Detach protective housing from control unit connectors.
Release connectors on engine control unit and unplug connectors.
Remove old
Simos control unit
J361
and install new
Simos control unit
J361
.
Installing
Simos control unit
J361
Installation is performed in the reverse sequence.
After installation, the protective housing must be re-fitted on the control unit.
Clean threaded holes for shear bolts to remove any residue from locking fluid. This can be done using a thread tap.
Always use new shear bolts.
After installing a new engine control unit, the following operation must be performed:
Activate engine control unit via
vehicle diagnostic, testing and information system
VAS 5051B
in
“Guided Functions”
mode,
“Replace engine control unit”
.