Kickdown Switch - Short Circuit to Ground

P1704

Kickdown switch - short circuit to ground

Function
The kickdown switch detects when the accelerator is depressed past the full-throttle position. It connects ground potential to the Tiptronic control module, which changes the shifting times for acceleration. The transmission shifts down immediately in accordance with the engine speed and does not shift up again until the maximum permissible engine speed is reached.

Diagnosis conditions
- Engine speed 448 rpm
- No throttle plate signal error stored

P1704:

Wiring diagram







Diagnosis procedure

NOTE: The function of the kickdown switch can be tested with the Porsche System Tester 2 (Input signals/Kickdown).







1 Check ground at Tiptronic control module connector.

1. Pull off Tiptronic control module connector.
2. Connect ohmmeter to Tiptronic control module connector pin 18 and ground. Indication:
Accelerator pedal in idle position
(kickdown switch open) = infinity Ohm
Accelerator pedal at stop
(kickdown switch closed) = 0... 5 Ohms

2 Check wire from Tiptronic control module to kickdown switch for short circuit to ground.

1. Additionally pull off connector on kickdown switch.
2. Connect ohmmeter to Tiptronic control module connector pin 18 and ground.

Indication: infinity Ohm

If 0... 5 Ohms is indicated, check wiring harness for crushing and chafing damage.