Volkswagen New Beetle. Manual - part 1628

 

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Volkswagen New Beetle. Manual - part 1628

 

 

EVALUATING DISPLAY ZONE 33, DISPLAY ZONES 1 - OXYGEN SENSOR CONTROL LEARNED 
VALUES BEFORE THREE WAY CATALYTIC CONVERTER (TWC) - 2 OF 2
 

Possible causes of malfunction if sensor control frequency is too slow: 

z

Slots or holes in sensor body are blocked  

z

Sensor vent hole in area of connecting wire is blocked  

z

Sensor has been overheated (glazed)  

z

Sensor has been damaged by leaded fuel  

Checking Oxygen Sensor wiring for oxygen sensor 1 

z

Remove inner plenum chamber cover, left: 

See PLENUM CHAMBER INNER COVER, REMOVING AND INSTALLING 

z

Connect VAG 1598/31 test box to control module wiring harness. Motronic Engine Control Module 
(ECM) -J220- is not connected by this action. 

z

Check Heated Oxygen Sensor (HO2S), 

see FUEL INJECTION SYSTEM 

COMPONENTS, CHECKING

Appears on 
display

Possible cause

Corrective action

High oxygen 
sensor control 
learned values

z

High learned values at idle speed, 

not so high learned values at part 

throttle: possible unmetered air in 

area of intake manifold  

z

Unmetered air between Mass Air 

Flow (MAF) sensor and throttle 

valve  

z

Fuel injector blocked  

z

Mass Air Flow (MAF) sensor 

malfunctioning  

z

Fuel pressure too low  

z

Heated Oxygen Sensor (HO2S) 

malfunctioning or oxygen sensor 

soiled  

z

Unmetered air at exhaust manifold 

gasket  

z

Check intake air system for leaks, see 

INTAKE AIR SYSTEM 

(UNMETERED AIR), CHECKING 

FOR LEAKS

z

Repair cause 

z

Check quantity injected, see FUEL 

INJECTORS, CHECKING

z

Check Mass Air Flow (MAF) sensor, 

see MASS AIR FLOW (MAF) 

SENSOR, CHECKING

z

Check fuel pressure regulator and 

holding pressure, see FUEL 

PRESSURE REGULATOR AND 

HOLDING PRESSURE, 

CHECKING

z

Check Heated Oxygen Sensor (HO2S), 

see FUEL INJECTION SYSTEM 

COMPONENTS, CHECKING

 

2003 Volkswagen New Beetle GLS 

1998-2004 ENGINE PERFORMANCE Multiport Fuel Injection (MFI) , 1.8L AWP, AWV - New Beetle

  

Fig. 106: Connecting VAG 1598/31 Test Box To Control Module Wiring Harness 
Courtesy of VOLKSWAGEN OF AMERICA, INC. 

z

Remove protective cover -arrows- and separate 6-pin connector (black) -1- to Heated Oxygen Sensor 
(HO2S) before Three Way Catalytic Converter (TWC) -G39-. 

 

2003 Volkswagen New Beetle GLS 

1998-2004 ENGINE PERFORMANCE Multiport Fuel Injection (MFI) , 1.8L AWP, AWV - New Beetle

  

Fig. 107: Separating 6-Pin Connector To HO2S -G39- Before TWC 
Courtesy of VOLKSWAGEN OF AMERICA, INC. 

z

Check wiring for open circuit between test box and 6 -pin connector (to control module) according to 
Electrical Wiring Diagram. 

z

terminal 1 + socket 70  

z

terminal 2 + socket 71  

z

terminal 5 + socket 51  

z

terminal 6 + socket 52  

Wire resistance: Max. 1.5 

 

2003 Volkswagen New Beetle GLS 

1998-2004 ENGINE PERFORMANCE Multiport Fuel Injection (MFI) , 1.8L AWP, AWV - New Beetle

  

Fig. 108: Identifying HO2S -G39- Before TWC Harness Connector Terminals 
Courtesy of VOLKSWAGEN OF AMERICA, INC. 

z

Additionally check wires all for short to one another. 

Specification: INFINITY ohm 

 

2003 Volkswagen New Beetle GLS 

1998-2004 ENGINE PERFORMANCE Multiport Fuel Injection (MFI) , 1.8L AWP, AWV - New Beetle

  

 

 

 

 

 

 

 

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