GTI V6-2.8L (BDF) (2002)
Coolant Temperature Sensor/Switch (For Computer): Testing and Inspection
With Generic Scan Tool
Engine Coolant Temperature (ECT) Sensor, Checking
NOTE: Use only gold-plated terminals when servicing terminals in harness connector of sensor.
Recommended special tools and equipment
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VAG1526 multimeter or VAG1715 multimeter
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VAG1594 connector test kit
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Wiring diagram
Test requirements
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The respective fuses of Motronic Engine Control Module (ECM) -J220- must be OK:
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Parking brake must be engaged or else daylight driving lights will be switched on.
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For vehicles with automatic transmission, selector lever must be in position -P- or -N-.
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Engine must be cold.
Function test
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Connect diagnostic tester.
See: Powertrain Management/Computers and Control Systems/Testing and Inspection/Reading and Clearing Diagnostic Trouble Codes/Scan Tool
Connecting/With Generic Scan Tool/Diagnostic Tester, Connecting
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Switch ignition on.
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Under address word 33, select "Diagnostic mode 1: Checking measured values."
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Select the measuring value "PID 05: Coolant temperature".
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Check specified value of coolant temperature:
If specified value is not obtained:
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Continue test according to the following table:
Indicated1)
Cause
approx. -40 degree C
Open circuit or short circuit to B+
approx. 140 degree C
Short circuit to Ground (GND)
1) If a temperature is indicated which differs greatly from ambient temperature of sensor, check sensor wires for contact resistance.
If specified value is obtained:
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Start engine and let run at idle. The temperature should climb uniformly
NOTE:
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The temperature increases in increments of 1.0 degree C.
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If the engine shows problems in certain temperature ranges and if the temperature does not climb uniformly, the temperature signal is intermittent
and the sensor should be replaced.