Skoda Workshop Service and Repair Manuals > Octavia Mk1 > Drive unit | 1.8 ltr./92 kW Engine - Fuel Injection and Ignition System Motronic | Mixture preparation system, electronic inj.,Gas | Testing auxiliary signals | Check signal for gearbox intervention during gearshifts

Check signal for gearbox intervention during gearshifts

Note

t	By means of this signal from the gearbox control unit, the ignition angle is briefly reduced (torque reduction) depending upon the speed and engine speed during gearshifts of the automatic gearbox, in order to avoid the jerky gear change.

t	The signal is a rectangular signal, which arrives at contact 23 at the engine control unit.

t	Due to the very short signal, the request for ignition angle relief from -V.A.G. 1552- is not always detected.

Special tools and workshop equipment required

t	Vehicle system tester -V.A.G 1552- with cable -V.A.G 1551/3-

t	Test box -V.A.G 1598/22-

t	Hand-held multimeter e.g. -V.A.G 1526 A- or multimeter -V.A.G 1715-

t	Voltage tester, e.g. - V.A.G 1527-

t	Measuring tool set - V.A.G 1594 A-

t	Current flow diagram

–	Connect -V.A.G 1552- → Chapter.

–	Conduct test drive and select read measured value block (function 08) and display group 019 → Chapter.

WARNING

The V.A.G 1552 should be operated by a second person.

Readout on display:

–	Display field 3 shows the gearbox intervention signal supplied by the gearbox for the gearshifts.

Specified value: X 1 X = without gearbox intervention

Specified value: X 0 X = gearbox intervention

Value: X = no meaning

–	Display field 4 shows the effective ignition angle (actual value).

–	The wiring to the gearbox control unit is monitored by the gearbox self-diagnosis (fault code 00545).

Reading measured value block 19       ->

1           2            3             4

–	During gearshifts if no read-out for the torque reduction is performed in the measured value block or the fault code 00545 is shown (in the gearbox control unit), connect the test box -V.A.G 1598/22- at wiring loom to engine control unit → Chapter.

–	Test wiring of contact 23 of engine control unit to gearbox control unit for open circuit and/or short circuit → Current Flow Diagrams, Electrical Fault Finding, Fitting Locations.

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