Volkswagen Golf Quiz
4- cylinder injection engine(1.4 1 direct inction. turbocharger)

Removing and installing engine control unit -J623- (with metal locking plate)

In this manual: 4- cylinder injection engine(1.4 1 direct inction. turbocharger)
General body repairs, exterior — 230General body repairs, interior — 279General information, paint — 133Vechile- specific paint information — 27Heating, air conditioning — 156Auxiliary heater — 58Air conditioning system with refrigerant R134a — 1297- speed dual clutch gearbox 0CW — 544- cylinder injection engine(1.4 1 direct inction. turbocharger) — 182Fuel supply system - Petrol engines — 59Running gear, axles, steering — 221Brake system — 92Wheels and Tyres guide — 12Guide for using trailers — 11Wheels and Tyres Guide - General Information — 121Brake system (hybrid) — 73Electrical system — 326Communication — 65Electrical system, general information — 111
~2min read

Special tools and workshop equipment required
Hot air blower -VAS 1978/14A--1- with nozzle -2- from wiring harness repair set -VAS 1978 B-

Small grinder (commercially available)

Vehicle diagnostic tester

Removing

  • 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 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.
Removing and installing engine control unit -J623- (with metal locking plate)
  • Release retaining clip -arrow- and take out engine control unit -J623-.
Note Cover the area around the engine control unit, and protect it from flying sparks.
Removing and installing engine control unit -J623- (with metal locking plate)
  • Make groove (for a screwdriver) in head of shear bolt -1- using a small grinder -2-.
Note
Removing and installing engine control unit -J623- (with metal locking plate)
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.
Removing and installing engine control unit -J623- (with metal locking plate)
  • Hold hot air blower -VAS 1978/14A- with nozzle attachment -arrow- to thread of shear bolt and heat thread for about 20 to 30 seconds.
Removing and installing engine control unit -J623- (with metal locking plate)
  • Unscrew shear bolt -1- using screwdriver -2-.
  • Detach metal locking plate from connectors for engine control unit -J623-.
  • Release and unplug connectors.

Installing

Installation is carried out in the reverse order; note the following:

  • The metal locking plate must always be re-fitted on the engine control unit -J623-.
  • 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 - Engine electronics

Guided Functions

01 - Renew engine control unit
Removing and installing engine control unit -J623- (with metal locking plate)

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