Technical BulletinImportant!Please give copies to allyour VW Technicians

C 24--99--04E 1999 Volkswagen of America, Inc.

1

Subject:

Model(s):

Group:

Number:

Date:

Thin Coating of Oil Collects on Mass Air Flow (MAF)Sensor

1996➤1998 to VIN: WM143854

2499--04Aug. 20, 1999All with 2.0L (OBDII)

Su p ersed es T.B. Gro u p 24 Nu mb er 99 -- 02 d ated Ap r. 12, 1999Superseded due to addition to VIN range, air cleaner inspection and Warranty Claim information

ConditionOil vapors from Positive Crankcase Ventilationsystem collecting on MAF sensor.

ServiceClean MAF sensor element and installbreather valve kit Part No: 037 198 002

-- Obtain radio code.

-- Note customer’s preset radio stations.

-- Ensure ignition is switched OFF.

-- Disconnect Battery Ground (GND) Strap.

MAF sensor, cleaning

-- Remove intake air duct (between MAFsensor and throttle body) and discard.

-- Remove MAF sensor.

-- Carefully clean MAF sensor from both sidesusing a solvent based electronic cleanerwhich is safe on plastics and leaves no resi-due, such as Part No. ZVW 805 001 or equiv-alent. One can will clean approx. 2-3 MAFsensors.

CAUTION!The MAF sensor film is very delicate.DO NOT touch the film during repair.DO NOT use any harsh cleaners such ascarburetor cleaners.Always read and follow precautionslisted on cleaner container.DO NOT use compressed air to dry.This will damage the MAF sensor.

(Cont. on Page 2)

50mm

60mm

A

24-A070

24-A071

A

Technical BulletinImportant!Please give copies to allyour VW Technicians

C 24--99--04E 1999 Volkswagen of America, Inc.

2

-- Inspect air cleaner for oil saturation andreplace if necessary.

-- Reinstall MAF sensor.

Breather valve, installing

-- Disconnect bottom vacuum hose from sideof intake manifold.

-- Disconnect top vacuum hose from side ofintake manifold to fuel pressure regulator.

-- Cut top hose 60mm from fuel pressureregulator.

-- Shorten remainder of hose to 50 mm, insertgreen plastic vacuum “T” between two hosesand reinstall hose to top port on intakemanifold with clamp.

-- Install previously removed bottom vacuumhose to open port of green plastic vacuum“T” with clamp (this leaves bottom port ofupper intake manifold free).

-- Install new intake air duct (between MAFsensor and throttle body) and connect tobreather valve.

-- Install support -A- on fuel line, route vacuumhose from new breather valve into clip asshown and connect to bottom vacuum port ofintake manifold with clamp.

(Cont. on Page 3)

24-A072

24-A073

24-A074

Technical BulletinImportant!Please give copies to allyour VW Technicians

C 24--99--04E 1999 Volkswagen of America, Inc.

3

Electrical harness, installing

-- Remove lower panel below fuse/relay panel.

-- Lower fuse relay panel.

-- Remove body plug (approx. 40mm) locatednear brake booster -arrow-.

-- Insert harness (with fuse, black and brownconnectors) through body panel to inside ofvehicle.

-- Fully seat grommet into body panel.

-- Route brown connector behind fuse/relaypanel bracket and insert into center ring ofbrown ground lug -arrow- at A-pillar.

-- Connect fused black connector to openterminal in black 4 point TV block locatedabove fuse relay panel or clipped to steeringcolumn bracket.

Note:

If black 4 point TV block has no open terminal,replace with Part No. 3A0 937 517 (8 point TVblock).

When connected, relay should activate withignition key in the ON position only.

-- Reinstall fuse/relay panel and lower panel.

(Cont. on Page 4)

24-A075

24-A076

Technical BulletinImportant!Please give copies to allyour VW Technicians

C 24--99--04E 1999 Volkswagen of America, Inc.

4

-- Route harness with existing enginecompartment harness to right side of vehiclebehind black plastic harness cover -arrows-.

-- Plug connector into resistor for newlyinstalled valve and tie-wrap harness asshown

-- Connect Battery Ground (GND) Strap.

-- Code radio.

-- Reprogram customer’s preset radio stations.

The procedure applies to vehicles withinthe applicable Emissions Warranty, usethe following:

Part Identifier: 2445

Labor Operation: 2445510 80TU

Use quantity .5 of Part No: ZVW 805 001 perWarranty claim.