System Diagnosis

Equipment Required for DME Testing:

1- Diagnostics tester 9288 with connecting leads
1- oscilloscope approved by Porsche
1- digital display multimeter with an internal resistance of at least 10 Mohm
1- Bosch L-Jetronic test lead, Bosch No. 1684 463 093 (check lead for correct polarity at plugs)
2- control unit plug test leads (shop-made) with 2 tab connectors no. 17.457.2 fitted to avoid damage to the plug terminals in the control unit plug during testing.
2- adapter test leads, consisting of: 4 plug connectors N 017.483.1 with 2 leads approx. 150 mm long, soldered.
1- three-pin test lead (e.g. VAG 1501).

Test Lead:

2- control unit plug test leads (shop-made) with 4 tab connectors N 17.457.2.

CAUTION: The test leads must always be used for the tests!

All sender and ignition timing signals of Porsche vehicles can be checked with the engine testers recommended by Porsche. Since instructions for connection of testers on a car will differ depending on the equipment manufacturer, these instructions must always be followed to ensure correct tester connection.


The following signals can be checked with the oscilloscope:
^ Engine Speed
^ ti signals (injection time)
^ Idle stabilizer
^ Hall sensor signal
^ Tank venting activation signal
^ VarioCam

Note: For USA vehicles, if a fault which affects exhaust gas composition is detected by the Check Engine lamp, and is read out, repair is possible with standard workshop tools.