Porsche 928 Diag


2. Check pilot pressure valve operation as described below:

Use System Tester 9288 to activate transverse lock solenoid (Drive links / Check transv. lock menu) with 1 - 2 pulses.

Then switch to pressure reduction position and read off gauge pressure after a short interval (to allow for gauge damping). For specifications, refer to p. D39-215.

3. Follow check by bleeding the transverse lock and correcting the reservoir level.

Execution / Notes

- Connect System Tester 9288 along with adapter line 9288/1 to diagnosis socket (located next to the passenger's seat under the booster cover). Bleed pressure gauge by clocking lock solenoid valve complete with System Tester in "Drive links / Bleed position" menu and allow brake fluid to escape from the pressure gauge at the bleeder valve until it is free from air bubbles. (Use collector bottle). For this purpose, leave bleeding device connected to reservoir and leave bleeding line clamped. Bleeding pressure approx. 1.5 - 2.0 bar. Close bleeding valve and press stop buttom. Select pressure reduction position. Switch off bleeding device.

Important note

If pilot pressure is too high (before replacing a valve), build up a lower pressure and reduce pressure by switching off the Ignition, thus deviating from the previous testing procedure. Pilot pressure may drop by max. 0.2 bar within 5 minutes.

- After disconnecting the pressure gauge, use the System Tester (Drive links - Select bleeding menu) and allow brake fluid to escape at bleeder valve of the transverse lock slave cylinder until fluid is free from air bubbles.

- Correct reservoir level with accumulator fully charged (after pump unit has switched off automatically) Do not fill above "max. mark".

Screw on reservoir lid. Open venting line at reservoir again. Disconnect System Tester.

Lateral acceleration sensor

Installation position

The lateral acceleration sensor has been installed on a support welded in under the LH seat.

The sensor is required for the electronically controlled limited slip differential.

1984 Porsche 928 Wiring Diagram
Do It Yourself Car Diagnosis

Do It Yourself Car Diagnosis

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