Porsche 1989 944 S2, Workshop Manual

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944 S/944 S2 Fuel System - Electronic Control
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Diagnosable DME Control Unit
Self-diagnosis with a fault memory, with which it is possible to detect and store certain injection.
ignition and knock regulating system faults, is integrated in the DME control unit of 944 S cars
beginning with 1988 models.
The DME control unit has a permanent positive connection to prevent cancellation of detected
and stored faults by turning off the ignition. Detected faults remain stored in the memory for at
least 50 engine starts (exception: idle speed switch interruption faults).
Important!
If the DME control unit plug or battery is disconnected, the fault memory and system adaptation
will be cancelled.
Tester Connections:
A 12-pin plug, which leads out of the DME wire harness in the passenger's footwell to the right
above the DME control unit, is provided for diagnosing in cars since 1988 models. 9268
Flashing Code Testers can be connected on this plug.
A 19-pin plug replaces the 12-pin plug beginning with 1990 (L) models. Either a 9288 System
Tester or the Flashing Code Tester (via adapter leads 9268/2) can be connected on this plug.
Operation of the testers is explained in the instructions supplied with the testers.
Note:
A pertinent test point is supplemented by a corresponding fault flashing code of Tester 9268.
Example:
Test Point 2 = idle speed contact (1-12)
Second digit display:
"1" fault exists
"2" fault does not exist
The following actual engine data can be read direct in the "actual value" menu with a 9288
System Tester beginning with the version 2.0 tester module status.
Intake air temperature
Ignition timing
Oxygen sensor voltage
Version code
Idle drive pulse duty factor
Engine temperature
Engine speed
Power supply
Air flow sensor signal
Load signal
DME - Diagnosing/Troubleshooting
Printed In Germany - XXI, 1989
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