Volkswagen New Beetle. Manual - part 1673

Fig. 57: Identifying Scan Tool Display - Checking IAT Sensor (1 Of 3)
Courtesy of VOLKSWAGEN OF AMERICA, INC. 

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Press buttons -0- and -8- for function "Read measuring value block" and confirm entry with -Q- button. 

Indicated on display 

Fig. 58: Identifying Scan Tool Display - Checking IAT Sensor (2 Of 3) 
Courtesy of VOLKSWAGEN OF AMERICA, INC. 

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Press buttons -0-, -0- and -4- for "Display group number 4" and confirm entry with -Q- button. 

Indicated on display (1 to 4 Display zones) 

Fig. 59: Identifying Scan Tool Display - Checking IAT Sensor (3 Of 3) 
Courtesy of VOLKSWAGEN OF AMERICA, INC. 

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Read off intake air temperature value in display zone 4. 

 

2003 Volkswagen New Beetle GLS 

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

  

Specification: approx. ambient temperature 

DISPLAY GROUP 4: GENERAL ENGINE DATA 

If the specification is not obtained: 

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Perform check according to following table:  

Evaluating display group 4, display zone 4 - Intake air temperature 

EVALUATING DISPLAY GROUP 4, DISPLAY ZONE 4 - INTAKE AIR TEMPERATURE 

 

Display zones

1

2

3

4

Display group 4: General engine data
Display

xxxx RPM

xx.xxx V

xxx.x °C

xxx.x °C

Indicated

Engine 

speed (in 

steps of 40)

Supply voltage for 

Motronic Engine 

Control Module (ECM) 

-J220-

Engine Coolant 

Temperature 

(ECT)

Intake air temperature

Working 
range

0 to 6800 

RPM

12.000 to 15.000 V

-48.0 to 143.0 °C

-48.0 to 143.0 °C

Specification 760 to 810 

RPM

(1)

 

700 to 750 

RPM

(2)

12.000 to 15.000 V

-

Approx. ambient temperature

(3)

-

-

-

If the specification is not 

obtained, see CHECKING 

WIRING , Evaluating display 

group 4

(1)

Engine idling at normal operating temperature for manual transmission

(2)

Engine idling at normal operating temperature for automatic transmission

(3)

If a temperature is displayed which is less than the ambient temperature of the sensor, check sensor 
wiring for transfer resistances. When doing this be aware that when stationary the sensor can be 
heated -up by radiated heat.

Display group: 4

Possible cause

Corrective action

Display zone: 4

Approx. -48.0 °C

(1)

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Wiring open circuit or 

short to positive  

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Continuation, see CHECKING WIRING

Approx. 143.0 °C

(1)

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Short to Ground (GND) 

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Continuation, see CHECKING WIRING

Approx. ambient 
temperature

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Signal periodically 

interrupted  

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Check sensor, see CHECKING WIRING , 

continuation for ambient temperature 

 

2003 Volkswagen New Beetle GLS 

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

  

If the specification is obtained: 

Continuation of check when display = ambient temperature: 

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Disconnect 2-pin connector -arrow- from Intake Air Temperature (IAT) sensor -G42-. 

Fig. 60: Disconnecting Pin Connector From Intake Air Temperature (IAT) Sensor 
Courtesy of VOLKSWAGEN OF AMERICA, INC. 

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Remove Intake Air Temperature (IAT) sensor -arrow-. 

(1)

If a temperature is displayed which is below the ambient air temperature of the sensor, check sensor 
wiring for transfer resistances. Note when doing this that sensor is heated from external sources, e.g. 
radiated heat when engine is not running.

 

2003 Volkswagen New Beetle GLS 

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

  

Fig. 61: Removing Intake Air Temperature (IAT) Sensor 
Courtesy of VOLKSWAGEN OF AMERICA, INC. 

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Re-connect 2-pin connector.  

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Note intake air temperature value in display zone 4.  

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Spray sensor -arrow- with commercial chilling agent while observing temperature value. 

 

2003 Volkswagen New Beetle GLS 

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