Equipment Required For Dme Tests; Sender Signals Which Can Be Checked With An Oscilloscope - Porsche 944 Workshop Manual

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Equipnient Required for DME Tests:
- Diagnostics tester 9288 (9268) with
connecting leads
- 1 oscilloscope approved by Porsche
- 1 digital display multimeter with an internal
resistance of at least 10 M-ohms
- 1 Bosch L-Jetronic test lead, Bosch No.
1684 463 093 (check read for correct
polarity in plugs)
- 2 control unit plug test leads (local
manufacture) fitted with 2 flat male plugs,
'N 17.457.2, in order to avoid damage on
plug pins in the control unit plug while
testing
- 2 adapter test leads, consisting of 4 plug
connectors, N 017.483.1, soldered with 2
approx. 150 mm lang leads
- 1 three-pin test lead (e.g. VW VAG 1501)
- 2 control unit plug test leads (local
manufacture) fitted with 4 flat male plugs,
N 17.457.2
Test leads must always be used for
testing!
D 24/28 - 4
Fuel System - Electronic Control
- All sender and ignition timing signals of
Porsche models can be checked with the
engine reglers recommended by Porsche.
Instructions for connection of testers on a
car will be different depending on the
make, so that it will always be necessary
to conform with the instructions supplied
with a pertinent tester.
Sender Signals Which Can Be Checked
With An Oscilloscope:
- Speed sender signal
- Injection ( ) signals
- Idle speed control activation signal
- Hall sender signal
- Ignition trigger signal to ignition final stage
- Tank venting activation signal
as well as:
- Reed switch signal (speedometer)
- ABS wheel sensor signals
DME - Diagnosing/Troubleshooting
944 S/944 S2
Printed In Germany - XXI, 1989