Volkswagen New Beetle. Manual - part 1669

Fig. 45: Identifying Throttle Valve Control Module Harness Connector Terminals 
Courtesy of VOLKSWAGEN OF AMERICA, INC. 

Engine Coolant Temperature (ECT) sensor -G62-, checking 

NOTE:

The Motronic Engine Control Module (ECM) - J220- will use a replacement 
temperature value for an engine start as soon as there is a DTC stored in the 

 

2003 Volkswagen New Beetle GLS 

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

  

Special tools, test equipment and auxiliary items 

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VAG 1551 scan tool or VAG 1552 mobile scan tool with VAG 1551/3B cable  

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VAG 1598/31 test box  

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VAG 1526 A or Fluke 83 multimeter  

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VAG 1594 adapter set  

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Electrical Wiring Diagram  

Test conditions 

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Engine must be cold  

Test sequence 

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Connect VAG 1551 scan tool ((VAG 1552). Switch ignition on and select Motronic Engine Control 
Module with "Address word" 01. Connecting scan tool and selecting Motronic Engine Control Module 
(ECM) -J220-, see VAG 1551, CONNECTING AND SELECTING MOTRONIC ENGINE 
CONTROL MODULE (ECM) -J220- .  

Indicated on display 

Fig. 46: Identifying Scan Tool Display - ECT Sensor, Checking (1 Of 3) 
Courtesy of VOLKSWAGEN OF AMERICA, INC.

DTC memory which affects the Engine Coolant Temperature (ECT) sensor - 
G62-. The temperature then rises according to a model stored in the ECM. When 
the engine has reached normal working temperature a fixed replacement value 
will be displayed after a certain period. This fixed value is also dependent on 
intake air temperature.

NOTE:

Only gold-plated terminals must be used to repair the terminals 3 and 4 in the 
connector for the Engine Coolant Temperature (ECT) sensor.

 

2003 Volkswagen New Beetle GLS 

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

  

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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. 47: Identifying Scan Tool Display - ECT Sensor, Checking (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. 48: Identifying Scan Tool Display - ECT Sensor, Checking (3 Of 3) 
Courtesy of VOLKSWAGEN OF AMERICA, INC. 

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Read Engine Coolant Temperature (ECT) value in display zone 3. Specification: approx. Engine Coolant 
Temperature (ECT)  

DISPLAY GROUP 4: GENERAL ENGINE DATA 

 

2003 Volkswagen New Beetle GLS 

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

  

If the specification is not obtained: 

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Perform check according to following table:  

Evaluating display group 4, display zone 3 - Engine Coolant Temperature (ECT) 

EVALUATING DISPLAY GROUP 4, DISPLAY ZONE 3 - ENGINE COOLANT TEMPERATURE 
(ECT) 

 

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 air temperature 

(3)

-

-

-

If the specifications are not obtained, see 

CONTINUATION OF CHECK WHEN 

DISPLAY APPROX. - 48 °C: , 

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 deviates greatly from the ambient temperature of the sensor, 
check sensor wiring for transfer resistances/open circuit.

Display 
group: 4

Possible cause

Corrective action

Display zone: 
3
Approx. -48.0 
°C 

(1)

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Wiring open circuit or 

short to positive  

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Continuation, see CONTINUATION OF CHECK 

WHEN DISPLAY APPROX. - 48 °C:

Approx. 143.0 
°C 

(1)

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Short to Ground 

(GND)  

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Continuation, see CHECKING WIRING

(1)

If a temperature is displayed which deviates greatly from the ambient 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