Gearbox: Electrical check — VW

Special tools, testers and auxiliary items

Hand multimeter V.A.G 1526 A
Adapter set V.A.G 1594 A
Test box V.A.G 1598/18
VAS 5051 Vehicle diagnosis, testing and information system

If VAS 5051 is used, V.A.G 1526 A is not required.

Additional information required

Workshop manual Caddy 1996 ▸, Polo Classic 1996 ▸, Polo estate 1998 ▸, Automatic gearbox 01M
"Current flow diagrams, Electrical fault finding and Fitting locations"binder

Test requirements:

Battery voltage in order.

Switch ignition and electrical consumers off before commencing the check (headlights, lighting, fan ...).
Fuses in main fuse box OK.
Fuses must be OK (remove fuses from fuse holder to check).

=> Current flow diagrams, Electrical fault finding and Fitting locations binder

The gearbox control unit (arrow) is located in the plenum chamber.

Check earth connections for corrosion and poor contact; repair if necessary.

Earth connection point is located to left of relay plate.
Check battery earth strap and earth strap between battery and gearbox.
Switch ignition off, release multi-pin connector and pull off control unit.
Fit test box V.A.G 1598/18 onto multi-pin connector (1) and lock, in direction of arrow (2).

Using test box V.A.G 1598/18 the wiring can be checked according to current flow diagram.

Before connecting the test leads the correct measuring range on tester must be adjusted. Otherwise the electronic components can be destroyed !

The specified values are valid for an ambient temperature from 0 °C...40 °C.
If the readings obtained differ from the specified values, determine fault on the basis of the current flow diagram.
If the readings obtained differ only slightly from the specified values, clean sockets and connectors of the testers and test leads and repeat test. Before replacing the particular components, test wiring and connections and, particularly if specified values are below 10 ω, repeat resistance measurement on component.

Control unit -J217- multi-pin connector (68 pin) assignment (sockets on V.A.G 1598/18)

1- · Earth (terminal 31) · 20- · Road speed sender -G68-
2- · Vacant · 21- · Gearbox speed sender -G38-
3- · Data bus wire. Only for vehicles with data bus · 22- · Solenoid valve 6 -N93- supply voltage
4- · Vacant · 23- · Supply voltage (terminal 15)
5- · Throttle valve potentiometer -G69- signal · 24- · Diagnosis K-wire
6- · Gearbox oil temperature (ATF) sender -G93- · 25- · Data bus wire. Only for vehicles with data bus
7- · Vacant · 26- · Vacant
8- · Vacant · 27- · Vacant
9- · Solenoid valve 3 -N90- · 28- · Throttle valve potentiometer -G69- earth
10- · Solenoid valve 7 -N94- · 29- · Selector lever lock solenoid -N110-
11- · Park/neutral signal · 30- · Vacant
12- · Kickdown for air conditioner · 31- · Vacant
13- · Ignition timing influence · 32- · Vacant
14- · Vacant · 33- · Vacant
15- · Brake light switch -F- signal voltage · 34- · Vacant
16- · Kickdown switch -F8- · 35- · Vacant
17- · Vacant · 36- · Vacant
18- · Multi-function switch -F125- · 37- · Vacant
19- · TD (revolution) signal · 38- · Vacant

39- · Vacant · 54- · Solenoid valve 2 -N89-
40- · Multi-function switch -F125- · 55- · Solenoid valve 1 -N88-
41- · Load signal from engine control unit. Only for vehicles with data bus · 56- · Solenoid valve 5 -N92-
42- · Engine speed sender -G28- Diesel engine (screening) · 57- · Selector lever display
43- · Road speed sender -G68- (screening) · 58- · Solenoid valve 6 -N93-
44- · Gearbox speed sender -G38- (screening) · 59- · Vacant
45- · Supply voltage (terminal 30) · 60- · Voltage supply (terminal 15)
46- · Vacant · 61- · Cruise control system (output) => current flow diagram
47- · Solenoid valve 4 -N91- · 62- · Multi-function switch -F125-
48- · Vacant · 63- · Multi-function switch -F125-
49- · Vacant · 64- · Engine speed sender -G28- (Diesel engine)
50- · Throttle valve potentiometer -G69- (5 volt) · 65- · Road speed sender -G68-
51- · Vacant · 66- · Gearbox speed sender -G38-
52- · Vacant · 67- · Solenoid valves voltage supply
53- · Vacant · 68- · Vacant

List of test steps (multi-pin connector with 68 pins) 1)

Component checked · Component checked
Supply voltage from control unit -J217- · - Perform test step 1 · Solenoid valve 6 -N93- · - Perform test step 10
Brake light switch -F- · - Perform test steps 2 · Solenoid valve 7 -N94- · - Perform test step 11
Throttle valve potentiometer -G69- · - Perform test step 3 · Kickdown switch -F8- · - Perform test step 12
Selector lever lock solenoid -N110- · - Perform test step 4 · Gearbox oil temperature sender -G93- (ATF) · - Perform test step 13
Solenoid valve 1 -N88- · - Perform test step 5 · Road speed sender -G68- · - Perform test step 14
Solenoid valve 2 -N89- · - Perform test step 6 · Gearbox speed sender / -G38- · - Perform test step 15
Solenoid valve 3 -N90- · - Perform test step 7 · Multifunction switch -F125- · - Perform test step 16
Solenoid valve 4 -N91- · - Perform test step 8
Solenoid valve 5 -N92- · - Perform test step 9

1)
Perform only the test steps listed in the fault table or in the measured value block according to component.