Note

Be sure to use correct control unit when replacing the units as it may be confused The only outward differences of the control units are the Bosch and Porsche part nos., 2. Take electronic control unit off the bracket after having undone the fastening nuts. 1. Fit electronic control unit bracket. 2. Attach multiplug safely to electronic control

Menu 1 fault memory

Fault Fault code Possible causes - Short to ground - may also be checked via menu 2 sensors. In this case, HF sensor defective appears regardless of the wheel position if there is a ground fault. - Disconnect the control unit plug and measure from PIN 18 to ground 5 kOhm would be displayed if there is no ground fault). Check the entire line path between control unit plug and HF sensor according to the circuit diagram. - Open circuit - may also be checked via menu 2 sensors. In this case, HF...

T

The diagram shows the interrelations of braking force, cornering force and slip. An increase in braking force causes a very fast reduction in cornering force and consequently in directional control and steerability of wheels. It is well known that absolutely no steering correction is possible when wheels have locked (100 slip the car slides straight ahead in spite of turned front wheels. The operating range of ABS is designed to always provide sufficient cornering force with simultaneous...

Important notes

Faults which were not present during the last journey and the test conditions applying them cannot be measured (with one exception). The relevant fault path should therefore be inspected visually. since with this type of fault the cause is either poor electrical contact, contact resistance or corrosion at the plug connections. Exception HF sensor signal not plausible (fault code 1-4). This fault is always output by the system tester as Not Present. However, it is possible that the fault is...

Exceptional regulations order processing

If the steering gear replacement proposed by the shop is refused by the customer or insurance company for financial reasons, an expert or, if this is not possible in foreign contries, the importer should be consulted (to be charged to the refusing party). If a decision is made against the above guidelines, it is recommended to file a note to this effect and have it signed by the expert. Power steering gears with no visible outside damage that require replacement can be supplied on an exchange...

Call up the Switch Inputs menu with the Pressure Switch display

Pressure Switch FL closed FR open RL open RR closed Coniune N 3. By pushing the car or, if it is on a hoist, by turning one wheel (for instance a rear wheel), position one of the pressure sensing switches precisely opposite its high-frequency transmitter. This adjustment can be carried out with the aid of the tester at the correct wheel position the display for the RL or RR pressure sensing switch changes from Open nach Closed (assuming that the tire pressure is correct in case of doubt,...

Changing the brake fluid bleeding the brakes

To ensure fast and efficient servicing, is is recommended to use a filling and bleeding device. The procedures described below were carried out with a Teves unit. For a detailed description of the unit, refer to the operating manual of the unit. Bleed both bleeder valves of each wheel of the four-piston fixed caliper brake. When changing the brake fluid, also drain some brake fluid from the bleeder valve of the clutch slave cylinder. Use only fresh DOT 4 brake fluid. Observe change intervals...

Check HF sender and ABS speed sensor

Each test with attenuated and unattenuated HF sensor - Required display OK* for attenuated HF sensor OK for unattenuated HF sensor Attenuated means Closed pressure-operated switch (Tire pressure greater than switching pressure) above the HF sensor - If display shows defective, there is a fault in the HF sensor or in the line to the control unit. Refer to menu 1 (fault memory) to remedy faults for fault code 1 - 4 a) Open pressure-operated switch (Tire pressure less than switching pressure)...

Checking and adjusting the rackandpinion power steering

Defects in the power steering arise as the result of a lack of oil in the hydraulic system. Because of the high oil pressure which builds up in the hydraulic circuit, even small leaks may lead to a loss of fluid, damaging the servo pump. Rumbling noises from the steering as ist is turned or foam in the lluid reservoir indicate low oil level and or air in the system. Before refilling the reservoir, eliminate any leaks on the intake side or replace the defective component on the delivery side. It...

Checking brake disc thickness

Measure brake disc thickness in approx. 8 places within the braking surface using a micrometer. DISASSEMBLING AND ASSEMBLING PARKING BRAKE LEVER Sometimes a washer is used to align parking brake lever Switch must respond before first catch align bracket if necessary DISASSEMBLING AND ASSEMBLING PARKING BRAKE LEVER 1. Remove parking brake lever parking brake cable trim. Unscrew mounting bolts and take out complete parking brake lever. 2. Pull off sleeve forward from parking brake lever (pasted...

Checking Delivery Pressure of Power Pump

Shut-off valve must be open (lever position I). 2. Turn steering wheel to left and right full lock and read off fluid pressure at pressure gauge. Specification 68 to 82 bar for power steering pump 928.347.431.04, 928.347.431.05 and 928.347.089.00. Specification 110 to 110 bar for power steering pump 928.347.089.01 (as of MY '91). Identification Nameplate on pump. Part No. and pressure specification are indicated on the nameplate.

Combined plug connections distinguishing line features

There are several combined plug connections of the same type in the lines for brake-pad wear, speed sensors and HF sensors. The lines in this area can be distinguished from one another as follows For brake-pad wear 2 lines protected by The HF sensor connectors have 1 pin and 1 socket. The connectors for the speed sensors have 2 pins with 2 sockets on the other side. Use 1 or 2 auxiliary cables (own construction) for measurements on the control unit connectors and plug connections with the same...

Dismantling and assembling steering wheel height adjuster of airbag vehicles

If not present, retrofit to modified steering wheel height adjuster (p. 48 - 40 ). Affected parts No. 1, 2, 4 and 6. always fit a new spring, making sure it is not bent when fitting fit modified version only (p. 48 - 40). replace if required. Coat inside with multi-purpose grease. replace if required. After adjustment, tighten setting nut No. 12).

General

As of MY '84, the Porsche 928 S is optionally available with anti-lock system (ABS) (option M593). As of model year 1986, the 928 S is fitted with ABS as standard equipment worldwide The anti-lock braking system represents an important contribution to the enchancement of active safety in the vehicle. The system prevents the wheels from locking when the brakes are applied, thus assuring full steera-bility and directional stability. Furthermore, the braking distance is optimized under all road...

Ih

Tighten to specified torque 150 Nm 108 ftlb. Tighten while holding rack and use torque wrench with special tool 9183 150 Nm 108 ftlb. Tighten while holding rack and use torque wrench with special tool 9183 Replace. Tighten to specified torque Run out rack ends completely and coat with VW steering gear lube AOF 086 000 Replace if necessary. Position correctly Not for new steering gears with bushings in mounting bosses Not for new steering gears with bushings in mounting bosses REMOVING...

Modifications to the steering wheel height adjuster

As of MY '92, axial locking of the operating level (No. 4) was improved by a spring clip (No. 1). This has entailed modification of the operating lever (No. 4) and of the eccentric (No. 6). The spring clip (No. 1) and two spring washers (No. 2) were newly introduced. In case of repairs, the modified design should also be adopted for vehicles prior to MY '92 equipped with airbag. Required parts New lever, new eccentric, two spring washers and one spring clip.

Notes on brake system from 1986 models on

For modifications to front-wheel fixed brake calipers and notes on replacement, refer to Pages 47-04 47-05. So that correct brake caliper position can be checked with the brake pads installed, the fixed calipers have an arrow mark above the Porsche logo to indicate the correct direction of brake disk rotation. For modifications to front-wheel fixed brake calipers and notes on replacement, refer to Pages 47-04 47-05.

Replacement

Make sure that the two brake calipers on an axle are both of the same pattern. New models have lock wire with wire guide Check, replacing if necessary. Wear limit 2 mm. It is better to mount pad after installation of brake caliper Replace if wire core is ground through Check, replacing if necessary. Wear limit 2 mm. It is better to mount pad after installation of brake caliper Drive off of floating frame with plastic hammer. Place piece of wood in caliper frame Don't mix up left and right...

Technical data as of MY

Brake booster Vacuum reduction factor Hydraulic twin-circuit brake system with front axle rear axle circuit division. Vacuum booster, internally vented brake discs with four-piston fixed caliper on front and rear axles. The pushrod circuit is assigned to the front wheels. ABS standard. 2 x 44 + 2 x 36 mm 2 X 30 + 2 X 28 mm Min. brake disc thickness * after machining Thickness tolerance of brake disc max. Runout of brake disc when fitted max. Surface roughness of brake disc after machining max....

Tire pressures on cars with RDK Important notes

The tire pressure control system takes the effect of tire temperature on tire pressure into account. Despite this, it is possible for the tire not to reach the nominal pressure only in a particular vehicle operating situation. In other words, a pressure loss display may not necessarily appear immediately the car is driven away. It may also fail to appear after switching the ignition off and on and driving the car away a second time. This merely indicates that the same vehicle operating...

Vehicles with PSD

The lock control assembly is located on an additional PCB in the ABS control unit. This PSD ABS control unit has 55 pins. Previous ABS control unit versions had 35 pins. When repairs are required, make sure the PSD ABS control unit is not confused with the PDAS ABS control unit fitted to the 911 Carrera 4. To tell the two versions apart, refer to the Part Nos. Control unit for 928 with PSD 928 618 Control unit for 911 Carrera 4 964 618

Important notes when working on vehicles with the tire pressure warning system

Always carry out a tire pressure warning system short test on the respective wheel every time a wheel or tire is changed. After the wheels have been finally balanced or after running on the test bench, erase the fault memory In the tire pressure warning system control unit. If Club-sport vehicles are fitted with winter tires, remove the spacer on the rear axle if necessary. This is only necessary if the vehicle is fitted with permitted rims having a different offset, if the spacers are not...

Conventional adjustment of tire pressure

If the Pressure Loss fault display appears, tire pressure at the affected wheel must be increased by 0.3 bar or at least to the specified pressure at that wheel. Since diffusion losses are approximately the same at the two wheels on any one axle, the tire pressure at the other wheel should therefore be increased by the same amouint. But do not reduce the tire pressure if too high a value is measured. The specified tire pressures at 20C are front 2.5 bar, rear 3.0 bar 2.5 bar for 17 summer...

Checking and correcting tire pressures

When tire pressures are corrected, a distinction has to be made between the conventional method (method A) and the more accurate method in conjunction with the 9288 system tester (method B). Do not check tire pressure by the conventional method (method A) unless pressure loss has been Indicated on the Instrument panel. By using the 9288 system tester, however, tire pressure can be checked and accurately adjusted at any time (method B). This is practicable during wheel and tire fitting work or...

Important notes on the diagnosis and assessment of RDK faults

When the RDK control unit plug Is disconnected, the display panel shows RDK SHUT DOWN after the engine has been started. This display is supplied from the instrument panel. If a wheel without a pressure sensing switch is fitted to the car, TIRE PRESSURE LOSS appears on the display panel after a short time, and the affected wheel is Indicated by an arrow. The system fault display takes precedence over the pressure loss display (in the event of pressure loss and an RDK fault, the RDK system is...

RDK possible fault displays and their causes Possible RDK fault displays

Tire pressure at each wheel is monitored by two pressure sensing switches installed in the wheel, if the tire pressure drops below the nominal value to which the pressure sensing switch is set, or if a system fault develops, a warning appears on the instrument panel the warning light at the top right comes on and the corresponding fault display is shown in the display panels. When the ignition is turned on, the warning light comes on as a bulb test. It goes out when the engine is started. Tire...

Tire pressure warning system

Two pressure-sensitive switches are allocated to each wheel, fitted to the rim well, 180 apart. The pressure-sensitive switches are subjected to the tire inflation pressure and act as switches for a resonant electric circuit, integrated into the pressure- sensitive wjtch- The resonant circuit remains closed as long as the tire inflation pressure remains above a specific setpoint value for the switch. If the inflation pressure drops below the setpoint value, the pressure-operated switch opens...

When pressing off the tire start at the valve since the levering force required in this area is somewhat lower

Then press off the tire on both sides, coating the rim flange with assembly compound. - Lift the first side of the tire over the assembly head (Fig. 1017 - 44). Place a rag or a leather cloth between the wheel and the tire lever. In addition, make sure the tire remains in the drop center opposite the disassembly head (Fig. 1018 - 44). Use Special Tool 9539 to facilitate this. - Remove the second side of the tire INSTALLING AND REMOVING WHEELS ON CAR Aluminum wheel nuts may only be loosened and...

If vehicles have aluminium joint carriers

Always turn the caster eccentric from small values towards large caster values, i.e. if the caster value is too high, first turn the eccentric back completely and then adjust to the correct value. This guarantees that the camber and caster values are always maintained, even under extreme operating conditions. If it is not possible to achieve the prescribed caster value, adjust the other side to the higher value if necessary (up to 4 degrees 30' is acceptable). Preparation Center steering gear...

Front axle

At actual vehicle height (Page 44 - 2 44 - 2a), measure the distance between the tire contact surface and the measuring point on the rear link bearing. the vehicle height is adjusted at the front axle by turning the adjusting nut. Set the wheels to a suitable lock to give access to the adjusting nut (do not raise the vehicle). Should the vehicle be raised, restore to actual vehicle height before checking the height again. - turn to the right vehicle higher - turn to the left vehicle lower...

Checkadjust height Note

The adjustment facility is used to correct differences between left and right wheel loads. If the height is correct, the differences in wheel load are within a permitted tolerance as long as the coil springs on each axle are the same length spring pretention). Tolerance 1 mm. It is possible to keep the differences in wheel load as low as possible if wheel-load scales are used. The tolerance between right and left on front and rear axles less than 20 kg. 2a) If spring struts are not adjustable...

Specimen measuring chart

Diffsrertca angla ot 20 turning radius 0 2 10 tOe-in Vehicle Empty weight according 1c- DIN 7CO20 (with full fuel lank, spare wfr* i and loots) Diffsrertca angla ot 20 turning radius 0 2 10 tOe-in 20 right turn-in measured I ell Vehicle Empty weight according 1c- DIN 7CO20 (with full fuel lank, spare wfr* i and loots) Car's he g hi (nominal valui 190 - 20 mm Car's he g hi (nominal valui 190 - 20 mm * Refer to instructions in Repaie Manual * Refer to instructions in Repaie Manual * The caster...

Tire and wheel overview tire specification character

For a tire and wheel overview for summer and winter tires, refer to the relevant Technical Information (T ), Group 4. When replacing summer tires, check for the correct tire specification character. The specification characters N 0, N 1, or N 2, respectively, help to distinguish summer tires approved by Porsche from other versions of identical tire type and the same tire size. The tires approved by Porsche are also identified in the corresponding Tl. NO, N1 and N2 tires must not be mixed on one...

Tire pressure of cold tires approx 20C summer and winter tires 15 and 16 inch

2.5 bar pos. pressure 2.5 bar pos. pressure 2.5 bar pos. pressure 3.0 bar pos. pressure front and rear 2.5 bar pos. pressure for 8 PR 89 P 92 P tires front only 2.2 bar pos. pressure for 4 PR 83 P tires * Due to changes in standards and legislation, V and ZR tires require tire pressures that deviate from the values indicated in the Owner's Manual. Always use the new tire pressures indicated above. Relevant adhesive labels are available from all official Porsche dealers. ** In some cases, only...

Wheels and tires Tire condition tire pressure

Tires are safety-relevant items that are only capable of meeting the requirements applicable if they are run at the correct tire pressure and with sufficient tread depth. The tire pressures indicated are minimum pressures. The tires must never be run at lower pressures since this affects roadhoiding In a negative manner and may lead to severe tire damage. Valve caps protect the valve against dust and dirt and therefore help prevent leaks. Always screw on caps tightly and replace missing caps....

Info

- The exploded drawing shows the front-wheel bearing arrangement of cars with sliding calipers. - If the front axle is equipped with floating calipers, brake caliper, brake disk, guard and steering knuckle are of different appearance and size. - The following components of four-piston fixed-caliper brakes differ in appearance and size brake disk, brake caliper, mounting bolts for caliper, outer wheel bearing, wheel hub, guard and steering knuckle. Mounting bolt (hex bolts for sliding and...

RDK Possible causes if a fault is indicated

Increase tire pressure at indicated wheel by 0.3 bar. Increase pressure at wheel on opposite side of same axle to the same pressure. Or Adjust tire pressures exactly with 9288 System-Tester (to 0.3 bar above the pressure-sensing switch trigger value). Tire wheel damage Display reappears at frequent intervals Leaking wheel rim or tire valve slow puncture in tire, damaged sealing ring at pressure-sensing valve. Fit the temporary spare wheel. Take car to Porsche dealer tire repair as soon as...

Accurate adjustment of tire pressures with the 9288 system tester

In view of tire pressure gauges' display tolerances and the difficulty of measuring the temperature of the air in the tire accurately, cars with what appear to be correctly adjusted tire pressures are very often only just above the switching threshold of the diaphragm-pattern pressure sensing switches. When a slight centrifugal force acts on the diaphragm at high speed, an entirely justifiable tire pressure warning is displayed. To avoid this problem, tire pressures in the workshop should...

Removing and installing relay General

The anti-lock system is fitted with three relays. The ABS relay (power supply for electronic control unit and scavenge pump motor relay) is located on the Central Electrical System. The relay for the solenoids and the relay for the pump motor are located below the cover of the hydraulic unit. 1. Flip up cover of Central Electrical System in the passenger's footwell. 2. With the ignition off, pull out and insert ABS relay, respectively (electronic relay with overvoltage protection). The relay is...

Psd

Possible fault displays via system tester 9288 DTC Fault type System allocation 11 Transverse lock valve PSD 12 Lateral acceleration sensor - PSD short circuit discontinuity 13 Lateral acceleration sensor - PSD signal implausible 14 Transverse lock - deviation PSD 15 Control unit - defective ABS PSD 21 Wheel speed sensor, front left ABS PSD 22 Wheel speed sensor, front right ABS PSD 23 Wheel speed sensor, rear right ABS PSD 24 Wheel speed sensor, rear left ABS PSD 31 ABS valve, front left ABS...

Checking Hydraulic Function of Steering Pressure Test Printed in Germany XXXIV 1994

REMOVING AND INSTALLING STEERING WHEEL 2. Mark position of steering wheel to steering shaft for reinstalling. 1. Install steering wheel with road wheels pointing straight ahead or according to disassembly mark in such a manner, that steering wheel spokes are horizontal. 2. Install hexagon nut with spring washer and tighten to specified torque. 3. Mount horn wires on impact pad and press impact pad on to retaining pins. 4. Check function of horns and direction indicator switch. X. Pull impact...

Tire pressure warning system RDK diagnosis General

- The system tester 9288 will be used for PORSCHE DIAGNOSIS from Mod. 89 onwards. PORSCHE DIAGNOSIS can be used for all systems capable of self diagnosis. Capable of self diagnosis means the control unit can detect, store and output system errors. Read out tire pressure loss event memory from control unit version R02 on introducing during 1991 model year . As the number of systems capable of self diagnosis will be increasing in the forseeable future, diagnosis of the relevant system will be...

Wheel alignment measuring data

The following values apply at empty weight in accordance with German DIN 70020 standard car with full fuel tank, spare wheel and tools . Measuring surface on rear control arm pivot Toe-out on turns at 20' steering lock Can only be varied by renewing steering arms From wheel contact patch to measuring surface on lateral subframe Height adjustment settings apply to new cars. After cars have been driven for a period the height may be max. 10 mm less, in other words the downward tolerance can vary...

Checking the ABS operation

If service operations not directly related to parts of the ABS have been carried out on the brake system, a simple functional check is sufficient. I.e. after starting the engine, the warning lamp in the instrument cluster must go off if the ABS system is o.k. Operations of this type include replacement of brake pads, brake hoses, brake discs, brake booster, tandem master cylinder, brake cables and components of the parking brake as well as brake pipes that are not screwed into the hydraulic...

Runout of removed

If the brake disc runout exceeds 0.1 mm, remove the brake disc and check runout of the wheel hub. Mark position of disc with regard to wheel hub. 3. Engage dial gauge holder, e.g. Ate Part No. 03.9314-5500.3 01, into brake caliper, determine center position and fit by turning the wing screw. If required, fit dial gauge holder with Ate conversion kit, Part No. 03.9314-5510.3 01 longer wing screw and bracket for dial gauge if required . Four-piston fixed...

All former steering gear versions are to be replaced with the current version 92834701027

The elastic steering stop, 928.347.329.03, for left and right sides is replaces by a solid steering stop, 928.347.329.04, for improvement in quality. At the same time it was necessary to replace the dust cover, 928.347.191.02, with a new version dust cover having a supporting lip, Part No. 928.347.191.03. Only the new steering stop 928.347.329.04 and the new bellows 928.347.191.03 are supplied for steering gear 928.347.010.24. The bellows 928.347.191.03 and the steering stop 928.347.329.04 are...

Dia left and right 23 mm

928.347.010.24 928.347.010.26 928.347.010.27 The steering gears with Part No. 928.347.010.22 former version and interim solution are no longer available. They should be replaced with the new current version. The steering gears of the new version 928.347.010.24 and 928.347.010.26 indicated in brackets have since been deleted as well status as of December, 1994 .

Installation

REMOVING AND INSTALLING SPEED SENSORS ON FRONT AND REAR AXLES 1. Take off front wheel. Remove intake hose on air cleaner. 2. Turn off ignition, take wire plug out of holder in engine compartment and disconnect. 4. Unclip wire on side member and in holders on steering knuckle. Loosen socket head screw and pull speed sensor out of steering knuckle. 3. Remove front exhaust shield to make procedures easier . Unclip wires on wheel housings and pull out with rubber grommet in direction of wheel. Also...

Important information on troubleshooting and ABS test program

Abs Led Tester

After certain repairs to the ABS system refer to functional check on page 45 - 07 , a test program using an ABS tester must be run. The ABS test plan, Print No. WKD 493 720, is required for this test operation and for troubleshooting. Following repairs affecting the ABS system cf. page 45 - 07 , a functional test using the ABS 2-LED tester must be run. 2 55-pin ABS 2-LED adapter lead. Same lead as for ABS testing on the 911 Carrera 4. Manufacturer and supplier Bosch. For address and order no.,...

Quick test of RDK

Whenever a wheel or tire is changed, it is essential to perform a quick test of the tire pressure control system. If only one wheel was removed, the quick RDK test need only be performed at this wheel. A short test drive for a distance of at least 20 meters, at a road speed of between 5 and 40 kph and at the following tire pressures is sufficient 1. Tire pressure 0.5 bar below nominal value front 2.0 bar rear 2.5 bar 2.0 bar for 17 summer tires The relevant arrow s must flash on the instrument...

Procedure for optimizing the wheels

The complete procedure is subdivided into 4 working steps 2. Stationary balancing of the wheel eliminating static and dynamic imbalance with optimization of smooth running 3. Fitting the wheel to the vehicle 4. Electronic fine balancing static balancing of the wheel on the vehicle after stationary balancing if required - not usually necessary Further to 1 Fitting the tire to the rim - Clean the rim above all, remove residua rubber and dried-on tire paste from the bead seat and the hump. -...

Technical Data Rear Axle

Wheel suspension Independent wheel suspension with lower diagonal suspension links and upper wishbones, coil springs and interna dampers. double-action hydraulic dampers page 42 - 18 d 0 22.5 x 3.5 mm tubular stabilizers modified in course of model year 1981 standard up to end of MY '91 Club-Sport-Version standard as of MY '92 Light alloy casting suspension link bearing for lower control arm 86 models onward to body Lower suspension link to transverse member camber eccentric Lower suspension...

Workshop Manual

Porsche 928 Lower Control Arm Bushings

PORSCHE Aktiengesellschaft TECHNICAL DATA Front Axle Suspension until end of model year 79 80 models onward 86 models onward control arm with coil spring and internal Double-action hydraulic dampers See page 40 - 51 dia. 28 mm x 4 tubular stabilizer with modified knuckle Spring strut and stabilizer linkage to lower control arm Stabi1izer clamp to longitudinal member Upper and lower control arms to steering knuckle Rubber bushing of piston rod of spring strut Ball joint,...