Testing clutch pedal switch — AUDI

ARH
This signal prevents engine speed fluctuations and load change jolts when the clutch is disengaged. The signal is also required for the cruise control system.

Connect vehicle diagnostic, testing and information system VAS 5051 (or fault reader V.A.G 1551) and select engine electronics control unit by entering address word "01" ( => Page
01-3
.)
When doing this the ignition must be switched on.

Rapid data transfer
HELP
Select function XX
Indicated on display:

Press keys 0 and 8 for the function "Read measured value block" and confirm entry with Q key.

Read measured value block
Enter display group number XXX
Indicated on display:

Press keys 0, 6 and 6 to select Display group 66 and confirm entry with the Q key.

Read measured value block 66
⇒
1
2
3
4
Indicated on display:

Observe display in display zone 2.

Display zones
1 · 2 · 3 · 4
Display group 66: Signals to engine control unit
Display · xxx km/h · 0 0 0 0 · xxx km/h · 0 0 0 0
Indicates · Actual speed / · Switch positions · Specified speed · Switch positions for cruise control system
Range · / · off = 0 / on = 1 · / · off = 0 / on = 1
Specification · 0 0 0 0
Note · Relevance of figures / => Page 24-141

Depress clutch pedal

Relevance of figures in 4-digit readout in display zone 2

x · x · x · x · Display zone 2
X · Brake light switch / 0 = Brake pedal not depressed / 1 = Brake pedal depressed
X · Brake pedal switch / 0 = Brake pedal not depressed / 1 = Brake pedal depressed
X · Clutch pedal switch / 0 = Clutch pedal not depressed / 1 = Clutch pedal depressed
X · Cruise control system (CCS) / 0 = CCS deactivated / 1 = CCS enabled

Display zones
1 · 2 · 3 · 4
Display group 66: Signals to engine control unit
Display · xxx /rpm · 0 1 0 0 · xxx km/h · 0 0 0 0
Indicates · Actual engine speed / · Switch positions · Switch positions for cruise control system
Range · / · off = 0 / on = 1 · / · off = 0 / on = 1
Specification · 0 1 0 0
Note · Readout must change from 0 to 1

Allow clutch pedal to return slowly to its normal position.
Readout should return from 1 to 0.

If readout does not change from 0 to 1:

Test voltage supply => Page
24-143
.

Testing voltage supply

Connect voltage tester V.A.G 1527 B as follows:

2-pin connector on wiring harness, socket · Earth
1 · Body earth

Switch on ignition.
The LED should light up.

If the LED does not light up:

Test for open circuit or short to earth in wiring between fuel pump relay and contact 1 on connector via fuse.

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

If the LED lights up:

Test wiring connections => Page
24-144
.

Testing wiring connection

Connect test box V.A.G 1598/31 to wiring harness for engine control unit. Do not connect to the engine control unit itself.
=> Page
24-10
.

Test the following wiring connections for open circuits and short to positive or earth.

2-pin connector on / wiring harness, socket · Test box V.A.G 1598/31, socket
2 · 39

Resistance in wiring: max. 1.5 ω

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

Rectify any open/short circuit as necessary.

If no open circuits are found in wiring:

Renew clutch pedal switch.