Checking on wiring loom plug: VW 2.0 (AAC)

Note:

On vehicles with automatic gearbox after the electrical check the fault "Engine/gearbox electrical connection: Open circuit" caused by the check and stored in automatic gearbox control unit (J217) must be erased.

=> Automatic gearbox 098; Repair group 01; Automatic gearbox 098 self-diagnosis; Interrogating and erasing fault memory.
Automatic gearbox 098
Automatic gearbox 098 self-diagnosis
Interrogating and erasing fault memory.

With ignition switched off pull plug -2- off Digifant control unit (J169) -3-. (The control unit is located in engine compartment on left in direction of travel).
Connect test box V.A.G 1598 to wiring loom plug -2-.
Carry out check according to following table.

Attention!
To prevent damage to the electronic components, switch to the respective measuring range before connecting the measuring cable, observe the test conditions and carry out the additional work listed in the table.
- Measuring range: Switch to voltage measurement -V-.
Test step · Item checked · ▪ Test conditions / - additional work · Test box sockets · Specifications1)
1 · Voltage supply for Digifant control unit (J169) · - Switch on ignition · 20 + 36 / 29 + 38 · app. battery voltage
2 · Wire from starter terminal / 50 · - Operate starter · 26 + 29 · min. 8 V
3 · Wire to fuel pump relay (J17) · ▪ Ignition switched on · bridge / 7 + 29 · Fuel pump must run audibly
4 · Wire to the injectors (N30...N33)2) · ▪ Ignition switched on / Remove fuse 18 / Bridge sockets 7 + 29 · 2 + 20 · app. battery voltage
53) · Activated charcoal filter solenoid valve 1 (N80) · ▪ Ignition switched on · 4 + 29 · app. battery voltage
6 · Wire to ignition trans. (N152) · ▪ Ignition switched on · 20 + 27 · app. battery voltage
74) · Cold start valve (N17) · ▪ Ignition switched on · 3 + 29 · app. battery voltage
8 · Idling stabilization valve / (N71) · ▪ Ignition switched on · 25 + 29 · app. battery voltage

1)
Observe notes => Page
01-34

2)
Checking injector resistance => Page
24-55

3)
Only on vehicles with activated charcoall filter system

4)
If fitted on vehicle

- Switch off ignition / Measuring range: Switch to resistance measurement -ω-.
Test step · Item checked · ▪ Test conditions / - additional work · Test box sockets · Specifications1)
92) · Wire to air conditioning compressor · - Separate single connector behind the relay plate · 37 + Contact with green wire · max. 1.0 ω
10 · Wiring to Hall sender / (G40) · - Pull plug off G40 (distributor) / Bridge contacts 1 + 3 of the plug · 13 + 30 · max. 1.5 ω
- Bridge contacts 1 + 2 of the plug · 11 + 13 · max. 1.5 ω
113) · Coolant temperature sender (G62) · --- · 13 + 14 · Fig. 01-40
12 · Intake air temperature sender (G42) · --- · 13 + 15 · Fig. 01-40

1)
Observe notes => Page
01-34

2)
Only vehicles with air conditioner.

3)
If the self diagnosis indicates a sender fault which is not established by this test, it could be caused by a temporary break in the temperature signal. In this case, additionally check the coolant temperature sender => Page
24-41
.

▪ Ignition switched off / ▪ Measuring range: Resistance measurement -ω- selected
Test step · Item checked · ▪ Test conditions / - additional work · Test box sockets · Specifications1)
132) · CO potentiometer (G74) in intake air temperature sender (G42) · --- · 13 + 35 · 0...2 kω
Idling switch (F60) · ▪ Throttle valve closed · max. 10 ω
- Open throttle valve · ∞ ω
143) · Wiring to throttle valve potentiometer (G69) · - Pull 3 pin connector off throttle valve potentiometer (G69) · 1 + con- / tact 1 / 12 + con- / tact 2 / 13 + con- / tact 3 · max. 1.5 ω

1)
Observe notes => Page
01-34

2)
According to equipment version the idling switch (F60) or the CO potentiometer (G74 will be checked.

3)
On disconnected throttle valve potentiometer connector.

▪ Ignition switched off / ▪ Measuring range: Resistance measurement -ω- selected
Test step · Item checked · ▪ Test conditions / - additional work · Test box sockets · Specifications1)
15 · Wiring to Lambda probe / (G39) · - Separate connector to G39 / Bridge contacts 2 + 3 of connector · 8 + 20 · max. 1.5 ω
- Reconnect connector to G39 · ∞ω
16 · Wire to white diagnostic socket · --- · 32 + Contact 2 on white diagnostic sok-ket (upper) · max. 1.5 ω

1)
Observe notes => Page
01-34

Fig. 1
Resistance graph for

Coolant temperature sender (G62)
Intake air temperature sender (G42) with CO potentiometer (G74)1)

1)
Vehicles ▸ 03.93

Scale A shows resistance values for temperature range 0...50 °C and scale B the values for temperature range 50...100 °C.

Examples:

30 °C corresponds to a resistance from 1500...2000 ω
80 °C corresponds to a resistance from 275...375 ω