Volkswagen New Beetle. Manual - part 1688

 

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Volkswagen New Beetle. Manual - part 1688

 

 

If the specification is obtained: 

z

Press --> button.  

z

Press buttons -0- and -6- for function "End output" and confirm entry with -Q- button.  

z

Switch off ignition. 

Continuation 

If the oxygen sensor control in display zone 1 does not fluctuate as stated: 

z

Press --> button.  

z

Press buttons -0- and -6- for function "End output" and confirm entry with -Q- button.  

z

Test drive vehicle to remove possible residue on oxygen sensor and repeat check. 

Observe the valid safety precautions when carrying out a road test, see SAFETY PRECAUTIONS . 

If the specifications in display zone 1 are not obtained even after a test drive, or the value does not 
fluctuate by at least 2%: 

z

Check oxygen sensor before Three Way Catalytic Converter (TWC) for aging, see OXYGEN SENSOR 
AGING, OXYGEN SENSOR BEFORE THREE WAY CATALYTIC CONVERTER (TWC), 
CHECKING
 .  

Evaluating display zone 33, display zones 1 - oxygen sensor control learned values before Three Way 
Catalytic Converter (TWC)
 

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

Appears on 
display

Possible cause

Corrective action

Low oxygen 
sensor control 
learned values

z

Low learned values at idling but 

with normal learned values at part 

throttle: possible oil dilution (high 

level of fuel in oil)  

z

Fuel injector leaking  

z

Fuel pressure too high  

z

EVAP solenoid valve 1 

permanently open  

z

Mass Air Flow (MAF) sensor 

malfunctioning  

z

Heated Oxygen Sensor (HO2S) 

malfunctioning or oxygen sensor 

soiled  

z

Check if it disappears after highway 

drive or oil change 

z

Check fuel injector, see FUEL 

INJECTORS, CHECKING

z

Check fuel pressure regulator and 

holding pressure, see FUEL 

PRESSURE REGULATOR AND 

HOLDING PRESSURE, CHECKING

z

Check EVAP solenoid valve 1, see 

OUTPUT DIAGNOSTIC TEST 

MODE (DTM)

z

Check Mass Air Flow (MAF) sensor, 

see MASS AIR FLOW (MAF) 

SENSOR, CHECKING

 

2003 Volkswagen New Beetle GLS 

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

  

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

  

 

 

 

 

 

 

 

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