Wiring and Component Check With Test Box V.A.G 1598/31
Wiring And Component Check With Test Box V.A.G 1598/31
NOTE:
- The test box V.A.G. 1598/31 is designed so it can be simultaneously connected to the control module wiring harness and to the control module itself.
- This has the advantage of enabling the engine management system to remain fully operational even with the test box connected (for example, when checking signals while the engine is running).
- The instructions for performing the individual tests indicate whether or not the engine control module itself also needs to be connected to the test box.
- Use multimeter Fluke 83 or equivalent and the diode test lamp V.A.G 1527 for the checks.
- To connect the testers to test box 1598/31, always use the adapter leads from adapter set V.A.G 1594.
CAUTION: To prevent damage to the electronic components, switch to the respective measuring range before connecting the measuring cable and observe the test requirements.
Connecting test box V.A.G 1598/31
- Switch ignition off.
- Remove cover of plenum chamber, right side.
- Loosen both screws (arrows) and pull engine control module in direction of travel and out.
As a deterrent against unauthorized access to the connectors on the engine control module, the control module -1- is bolted to a metal casing -4- by means of a locking plate -2- and shear bolts -3-.
The threads of the shear bolts are additionally coated with a thread-locking compound to make them more difficult to remove.
In order to disconnect the connectors from the engine control module (for instance when connecting the test box or replacing the control module), the control module must be separated from the protective casing. The required procedure is described below:
Required tools and equipment
- Hot air blower -1- (from wiring repair set VAS 1978)
- Nozzle attachment -2- (also included in wiring repair set VAS 1978)
- A normal (commercially available) vise-grip wrench
Work sequence
CAUTION: Keep exactly to the following procedure to avoid damage (burning) to the wiring, connectors, insulation or the control module. Follow the operating instructions supplied with the hot air blower.
- Pivot engine control module with protective casing towards engine compartment so that locking plate (item -2- in illustration) is visible. Place a clean cloth under engine control module with protective casing.
- Set controls on hot air blower as shown in illustration: temperature control -2- to maximum heat and two-stage air delivery switch -3- to setting 3.
NOTE: In the next step the blower is used to heat the threads for the shear bolts in the locking plate. This reduces the effect of the thread locking compound so the bolts can then be more easily removed.
WARNING: When the threads in the locking plate are heated the shear bolts and parts of the metal casing are also heated. Be careful not to burn your hands. Also make sure that, as far as possible, heat is applied only to the threads and not to the adjacent parts. Cover these parts if necessary.
- Apply nozzle -1- of hot air blower to thread in locking plate so that nozzle surrounds thread. Nozzle may rest against top of metal casing.
- Switch blower on and apply heat to thread for about 20 to 25 seconds.
- Apply vise-grip wrench -1- to bolt head -2- and unscrew shear bolt in direction indicated (arrows).
- Repeat procedure for second shear bolt.
NOTE: Be particularly careful at the second shear bolt location because the control module connectors are very close to the bolt.
- Apply nozzle -1- of hot air blower to thread in locking plate so that nozzle surrounds thread. Nozzle may rest against top of metal casing.
- Switch blower on and apply heat to thread for about 20 to 25 seconds.
- Apply vise-grip wrench -1- to bolt head -2- and unscrew shear bolt in direction indicated (arrows).
The engine control module can now be separated from the metal casing.
- Release connectors on engine control module and disconnect connectors.
- Connect test box V.A.G 1598/31 to connector on wiring harness. Also connect Ground clamp (arrow) to Ground. Instructions for individual tests indicate whether or not engine control module itself also needs to be connected to test box.
- Perform test as described in relevant repair instructions.
Installing engine control module
Installation is performed in the reverse sequence. Make sure to install the protective casing to the engine control module. Use new shear bolts when installing the protective case.