BMW 3 Series Service Manual (E39)

!is set and the MIL is illuminatedwhen OBD I1 fault criteria are exceeded. The ECM then operatesthe engine usingthe ECT

type sensor. In other words, a> the temperature rises, resistance through the sensor decreases.

Fuel Injection

4 Remove electrical harness connector (arrow) from IAT sen-

MS 42.0 throttle valve assembly, replacing

<The motor driven throttle valve for the MS 42.0 system is referred to as MDK (motor driven throttle valve). The MDK unit is electronically operated to regulate intake air flow by the ECM.

The MS 42.0 system uses a throttle cable from the accelerator pedal to the MDK unit. The throttle cable is connected directlyto the integral pedal position sensor (PWG) in the MDK unit.This sensor communicates pedal position to the ECM, which in turn electronically regulatesthrottle plate position. The MDK pulley is linked to the throttle shaft by springs to allow ASC interventionto override the driver's pedal position.

NOTE-

The MDIC unit is non-adjustable and must be replacedas a complete unit if found to be faulty.

i f replacing the MDK unit, the adaptation values stored in the ECMmustbe clearedand the new unit initialized using BMW special service tools.

CAUTION-

If the adaptationprocess is not completedcorrect& the engine wiiinot start.

-Disconnect battery negative (-) cable in luggage compartment.

CAUTION-

Prior to disconnectingthe battern read the battely disconnection cautions in 001 General Warnings and Cautions.

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4Remove dipstick guide tube:

Disconnect wiring harness brackets from tube (A).

Unclip fuel lines from dipstick tube (El).

Remove lower guide tube mounting bolt (C).Pull out dipstick guide tube.

<If necessary, disconnect electrical harness connector at fuel tank venting valve (A). Disconnect hose at quick disconnect fitting (arrow).

Working at throttle housing, turn harness plug counterclockwise and disconnect. Remove throttle assembly mounting fasteners (arrows) and pull assembly off manifold.

Installation is reverse of removal

Replace sealing ring between throttle assembly and intake manifold.

0 Reattach throttle assembly harness connector with care. Arrow on fully tightened connector must line up with corresponding arrow on throttle assembly housing.

* Connect BMW test equipment or equivalent and carry out throttle plate adaptation following the on-screen directions.

Reattach throttle cable and check cable adjustment as described under Throttle cable, adjusting (MS 42.0).

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MS 43.0 throttle valve assembly, replacing

The electronic throttle valve assemblyforthe MS43.0 system is referred to as EDK (electronicthrottle valve). There is no mechanical (cable) link betweenthe accelerator pedal and the throttle plate.

<The accelerator pedal module (PWG) at the pedal assembly communicates the pedal position directly to the ECM. The module provides two variable voltage signals (via two Hail sensors) to the ECM for pedal position and rate of movement.

NOTE-

The EDK unit is non-adjustableandmustbe replaced as a complete unit if found to be faulty

If replacing the EDK unit, the adaptation values stored in the ECMmustbe clearedandthe new unit initialized using BMW special service tools.

CAUTIOIG

If the adaptationprocessis not completedcorrectk the enqine willnot start

-Disconnect battery negative (-) cable in luggage compartment.

CAUTION-

Prior to disconnectingthe battery, read the batterydisconnectioncautionsgiven in001 General Warnings and Cau- tions.

<-Remove complete air filter housing:

Disconnect electrical harness connector on mass air flow sensor (A).

Disconnect vacuum line at intake boot (6) .

Loosen intaite air duct clamp (C).

Remove filter housing mounting screws.

Disconnect air duct and lift complete air filter housing and MAF sensor out of engine compartment, pulling it forward away from throttle housing.

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4 If necessary, disconnect electrical harness connector at fuel tank venting valve (A). Disconnect hose at quick disconnect fitting (arrow).

<Worlting at throttle housing, turn harness plug counterclockwise and disconnect. Remove throttle assembly mounting fasteners (arrows) and pull assembly off manifold.

-Installation is reverse of removal.

0 Replace sealing ring between throttle assembly and intake manifold.

Reattach throttle assembly harness connector with care.

0 Arrow on fully tightened connector must line up with corre-

-sponding arrow on throttle assembly housing.

Use BMW scan tool to reset ECM adaptation values.

130-38

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Throttle cable, adjusting (MS 42.0)

The throttle assembly on MS 42.0 cars uses a throttle cable. The cable should be adjusted any time it is disconnected or replaced. This procedure requires the factory scan tool or an equivalent to read and adjust throttle angle. It is recommended the procedure be done by an authorized BMW dealer service department

Basic adjustment:

Ensure that at idle (accelerator pedal in rest position) throttle cable has detectable play at throttle lever attaching point. Play must not exceed maximum allowable.

Adjust by turning knurled adjuster (arrow) on end of throttle cable sheath at throttle housing.

NOTE-

Faulty throttle adjustment values must be reset using the

BMW service tester DISplus, MoDiC, GTI or equivalent.

ldle speed control valve, checking and replacing

The Idle speed control valve regulates Idle speed by red~recting air around the throttle valve. The ldle speed control valve is mounted d~rectlyabove the throttle housing. Accessing the valve is best accomplished by flrst removing the air fllter housing and associated ducting.

Thevalve is supplied with batteryvoltage from the ECM relay. The idle speed control valve incorporates a two-coil rotary actuator. The ground sides of each coil are pulsed simultaneously by the ECM. The duty cycle of each circuit is varied to achieve the required idle speed.

A faulty idle speed control valve sets a fault code and the MIL is illuminated when OED II fault criteria are exceeded.

Before checking the idle speed control valve, confirm that the throttle position sensor is working correctly.

-With engine running, check that idle speed control valve is buzzing.

-Turn on AIC system or shift transmission into drive. ldle should remain steady or increase slightly.

-If idle speed valve is not buzzing, or if idle decreases when AIC is turned on, stop engine and disconnect harness connector from idle speed valve.

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CAUTIOIG

Besure ignitionis OFFbefore disconnectingor reconnecting

DMEsystem components.

-To remove valve, remove cable bracket mounting bolt and idle speed control valve mounting bracket bolts from front of throttle housing and remove idle speed control valve with attached bracket.

NOTE-

When installing idle speedcontrol valve, remove intake boot sealing ring from valve and installinto intake air boot. Then install valve info sealing ring.

Evaporative emissions control diagrams

MS 42.0 (LDP)

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Evaporative emissions control,

(MS 42.0,MS 43.0)

E39 models with MS42.0 or MS43.0 engine are equipped with a fuel system evaporative pressure leak diagnosis system. The main component of this system is the leak diagnosis pump (LDP or DM-TL). The function of either system is to pressurize the fuel tank and the evaporative emission system for the purpose of detecting leaks.