Volkswagen Golf/Jetta/Cabriole 1990-1999

Coolant Temperature Sensor

Print

Description



Monotronic System

The Engine Coolant Temperature (ECT) sensor is mounted in the water outlet on the back side of the head. If you vehicle still has a original VW part it will be black in color with a four terminal connector. This device signals the engine management system with the current coolant temperature, the ECU takes this information and uses it to control other such circuits as the idle speed, knock control system, oxygen sensor circuit, exhaust gas recalculation, and fuel tank venting. It is also important to note that if at any time ECU does not receive a signal from the ECT it will substitute a value of 176°F (80°C).

VR6

The Engine Coolant Temperature sensor is mounted in the thermostat housing. The body of the sensor will be blue and the sensor will be blue and have two terminals if it is an original factory VW part.

Digifont

There are two coolant temperature sensors mounted in the upper radiator hose-to-engine flange. The black connector is for the gauge on the instrument panel. The blue connector is for the ECU.

There is also an air temperature sensor at the inlet end of the air flow sensor. Both temperature sensors operate with the same resistance values.

TESTING



Motronic
  1. Unplug the sensor connector and use an ohmmeter to check sensor resistance:

    55°F (13°C)-3000-3800 ohms
     
    65°F (18°C)-2200-3000 ohms
     
    75°F (24°C)-1800-2500 ohms
     
    85°F (29°C)-1500-2100 ohms
     
    150°F (65°C)-400-550 ohms
     
    200°F (93°C)-200-270 ohms
     

  2.  

Digifont
  1. Unplug the sensor connector and use an ohmmeter to check sensor resistance:

    1.55°F (13°C)-3000-3800 ohms
     
    2.65°F (18°C)-2200-3000 ohms
     
    3.75°F (24°C)-1800-2500 ohms
     
    85°F (29°C)-1500-2100 ohms
     
    150°F (65°C)-400-550 ohms
     
    200°F (93°C)-200-270 ohms
     

  2.  

 
label.common.footer.alt.autozoneLogo