Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
SYS.OK|MANUAL.DB● LIVE
HOMESERVICE MANUALSVOLKSWAGEN2003PASSAT SEDAN 4MOTION (3B3) W8-4.0L (BDP)REPAIR AND DIAGNOSISPOWERTRAIN MANAGEMENTCOMPUTERS AND CONTROL SYSTEMSCOOLANT TEMPERATURE SENSOR/SWITCH (FOR COMPUTER)TESTING AND INSPECTIONENGINE COOLANT TEMPERATURE (ECT) SENSOR (ON RADIATOR), CHECKING
2003 Volkswagen Passat Sedan 4Motion (3B3) W8-4.0L (BDP)
Engine Coolant Temperature (ECT) Sensor (on Radiator), Checking
2003 Volkswagen Passat Sedan 4Motion (3B3) W8-4.0L (BDP)SECTION Engine Coolant Temperature (ECT) Sensor (on Radiator), Checking
Engine Coolant Temperature (ECT) Sensor (on Radiator), checking
Recommended special tools and equipment
- VAG1526 multimeter or VAG1715 multimeter
- VAG1594 connector test kit
- Wiring diagram
Test requirements
- The respective fuses of Motronic Engine Control Module (ECM) -J220- must be OK:
- Fuses -1, 2, 3, 4 and 7- in protective housing (plenum chamber, left) must be OK:
- Ground (GND) connections between engine and chassis must be OK.
- Ignition switched off.
Test sequence
- Disconnect 2-pin connector from Engine Coolant Temperature (ECT) Sensor (on Radiator) -G83- (arrow).
Checking resistance
- Measure resistance at Engine Coolant Temperature (ECT) Sensor (on Radiator) -G83-.
- Range A displays resistance values for the temperature range of 0 to 50 degrees C, range B displays resistance values for the temperature range of 50 to 100 degrees C.
Read-out examples:
30 degrees C is in range A and corresponds to a resistance of 1.5 to 2.0 k Ohms
80 degrees C is in range B and corresponds to a resistance of 275 to 375 Ohms
If specified value is not obtained:
- Replace Engine Coolant Temperature (ECT) Sensor (on Radiator) -G83-.
WARNING:
- Cooling system is under pressure.
- Danger of scalding when opening!
- Erase DTC memory of Engine Control Module (ECM), Diagnostic mode 4: Reset/erase diagnostic data.
- Generate readiness code. Monitors, Trips, Drive Cycles and Readiness Codes
If specified value is obtained:
Checking wiring
- Connect test box to control module wiring harness, connect test box for wiring test. Test Box, Connecting For Wiring Test
- Check wires between test box and 2-pin connector for open circuit according to wiring diagram.
Terminal 1 + socket 17
Terminal 2 + socket 50
Wire resistance: max. 1.5 Ohms
- Also check wires for short circuit to each other, to vehicle Ground (GND) and to B+.
Specified value: Infinity Ohms
- Erase DTC memory of Engine Control Module (ECM), Diagnostic mode 4: Reset/erase diagnostic data.
- Generate readiness code. Monitors, Trips, Drive Cycles and Readiness Codes
If no malfunctions are detected in the wires and the resistance values are OK:
- Replace Motronic Engine Control Module (ECM) -J220-.
RENDER: 1.0x
NO RELATED
Recommended Tools & Savings
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Affiliate disclosure: We may earn a commission at no extra cost to you.
When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.