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Home >> Porsche >> 1990 >> 928 GT V8-4957cc 5.0L >> Repair and Diagnosis >> Powertrain Management >> Computers and Control Systems >> Testing and Inspection >> Pinpoint Tests >> LH Test Points (Fuel Injection) >> Test Point 6 - Idle Speed Control

Test Point 6 - Idle Speed Control

TEST POINT 6 - Idle speed control (V) - Fault code 1_22

Possible Causes, Elimination, Remarks
Call up actuator activation menu point.

If no pulse is audible, check: Power supply.




- Connect voltmeter to terminal 2 of disconnected idle speed actuator plug and ground with the test leads. Switch on the ignition.

Display: battery voltage.
No display: Check power supply according to wiring diagram.

Checking the control signal
- Insert 2-pin DME test lead (Bosch No. 1 684 463 093) between rotary actuator and plug connection.
- Connect engine tester as stated in manufacturer's instructions, and adjust.
- Make sure that there is no contact between the lead connections and ground on the vehicle (risk of short circuit).
- With the engine running, the following display must be seen:




Frequency approx. 100 Hz.

If there is no audible pulse in spite of the power supply and the signal being present, renew the idle speed control.