Warm up the engine to operating temperature until the cooling fan comes on.
Measure the voltage between pins 7 (Yellow/Green (+)) and 32 (Black (-)).
If the voltage is approximately 1 V, the TW sensor is normal.
Otherwise, turn off the ignition.
Next, disconnect the 7-pin connector from the right front of the engine compartment.
Turn on the ignition.
Measure the voltage between pins 7 (Yellow/Green (+)) and 32 (Black (-)).
If the voltage is not approximately 5 V, the control unit should be replaced and retested.
If the voltage is approximately 5V, then measure the resistance between the Yellow/White and Black terminals on the main engine wiring harness.
If the resistance is not in the range of 200-400 Ohms, then you should check for an open or short circuit in the Yellow/White and Black wires between the TW sensor and the 7-pin connector. If the wires are normal, then you should replace the TW sensor.
If the resistance is in the 200-400 ohm range, then measure the voltage between the Yellow/Green (+) terminal on the main engine wiring harness and ground.
If the voltage is approximately 5V, then the break in the Black wire between the 7-pin connector and point G2 should be repaired.
Otherwise, the open or short circuit in the Yellow/Green wire between the 7-pin connector and terminal 7 of the control unit must be repaired.