Initial Inspection and Diagnostic Overview

Definitions

These explanations refer only to this assembly group: 4-speed automatic transmission 01P On Board Diagnostic from 01.95. These definitions are not necessarily generally valid.

ABS
Anti-locking brake system. Further information on the ABS can be found in the relevant self-study programs.

Display group number See Read Measuring Value Block

ATF (Automatic Transmission Fluid)
Transmission oil for automatic transmission

Data bus
Transportation of data. To do this the electrical signals are brought into a certain format (bus). Further information on this can be found in Self- study program No.186.

Data bus low (high)
The voltage used to transport the data is low (high). Further information on this can be found in self-study program no.186.

Throttle valve potentiometer
An engine component. The "throttle valve signal" originates from here.

Throttle valve control module

Influencing the quantity injected
Reduction in engine torque during gear change by adjusting quantity of fuel injected. Further information on this can be found in self-study program no.232.

Performing electrical check
A targeted check of the electronic components by performing certain measurements.

Electronic Power Control (EPC)
Terms like EPC, electronic accelerator, accelerator module and electric throttle operation all refer to a regulating system. It includes in one component, among other things, senders -G79- and -G185- and a throttle valve positioner.

Because EPC is always a component of engine control, it communicates initially with the engine control module. But because, for example, the signal for the kickdown switch is also generated in the EPC, the engine control module sends the data into the data bus, in order that other control modules have access to it.

Further information on this subject can be found in
- Self-study program no.210.

Vehicle Diagnostic, Testing And Information System VAS 5051
Replaces and supplements all functions that were performed previously using scan tools V.A.G 1551 or V.A.G 1552.

Further information on this subject can be found in self-study program no.202.

Throttle position sender
See Electronic Power Control (EPC)

Road speed sender -G68-
The sender records the speed of the output gear and transmits it to the automatic transmission control module (not to the speedometer). Further information on this can be found in self-study program no.172.

Initiating basic setting
The learned values in the control module are set back to the initial values. Further information on this can be found in self-study program nos. 172 and 232.

No communication
There is no connection for exchanging information between the control modules.

Kickdown switch -F8-
The kickdown switch is integrated in the accelerator cable of vehicles without EPC and in the accelerator pedal position sender of vehicles having EPC. When the accelerator pedal is pressed to its stop, the transmission downshifts for acceleration.

Short to Ground
Current flows -incorrectly- to Ground without supplying a consumer.

Short to positive
Current flows -incorrectly- to a live component without supplying a consumer.

Wiring
Routing of electrical wiring and components in vehicle.

Selector lever lock magnet -N10-
Located in the selector mechanism close to the selector lever. Prevents movement (involuntary) of the selector lever from positions "P" and "N" as long as the brake pedal is not depressed.

Solenoid valves
Opens and closes the oil channels to the clutches and brakes.

Read Measuring Value Block
The control module can transfer a considerable amount of test data. This test data delivers information on the operational condition of the system and/or sensors connected to it. In many cases the transferred test data supports troubleshooting and corrective action. The test data has been summarized into single display groups because all the information cannot be evaluated at the same time. The information can be selected via display group numbers.

(If you can only select a two character display group number, you have an old program card in your V.A.G 1551! Replace the card with a valid version).

Each display group number is displayed on the scan tool as four display zones.

A display zone can be displayed as an eight digit row or as values. These values are sometimes displayed with a measurement symbol.

Emergency running
"Condition of the control module" when certain malfunctions are recognized in order to maintain driving safety, to protect the transmission against damage and at the same time to ensure that driving characteristics are impaired as little as possible.

Pendulum support
Designation of a part of the assembly mounting. Further information on this can be found in self-study program no.166.

Program card version
Always use the most up-to-date program card. Further information can be found in the test unit operating instructions.

Sporadic
Happens occasionally

Stationary uncoupling
The transmission control module hydraulically shifts to Neutral, uncoupling the engine, when a driving range is selected, the vehicle is stationary and the brake pedal is applied (e.g. at a stop light).

Static
Present at the moment, continuous

TDC signal
The signal is used to calculate the engine speed.

Infinity Ohms
The resistance is infinite, open circuit.
Ohms = Ohm

TCC (Torque converter lock-up clutch)
Transfers the engine torque mechanically to the transmission.

Selector lever position display
Shows in the instrument cluster the position of the selector lever. Further information on this can be found in self-study program no.232.

Ignition key withdrawal lock
Ensures that the ignition key can only be withdrawn when park position is selected and in addition mechanically locks the selector lever in this position.

Ignition timing control
The engine torque is reduced during the gear change process by changing the ignition timing. Further information on this can be found in self-study program nos. 172 and 232.