51
Group 23 EDC III
Electronic fault detection
Checking the coolant level
sensor
1.
Empty the coolant from the expansion tank.
Warning!
NEVER open the expansion tank’s
pressure cap when the engine is warm. Hot coo-
lant could spray out, causing burns.
2.
Disconnect the connector from the coolant
sensor.
3.
Check that the contact is activated and sends
a signal when the expansion tank is empty.
4.
Then fill the expansion tank with coolant and
check that resistance remains the same.
Checking the combined sensor
for oil pressure/temperature
Checking the function of oil pressure
1.
Switch off the engine
2.
Disconnect the connector from the oil pressure
sensor and connect 4-pin adapter 9998534 bet-
ween the sensor connector and the engine wiring.
Then connect multimeter 9510060-8 between me-
asurement points 1-4.
3.
Switch on the operating voltage.
4.
Measure using a multimeter set to measure volta-
ge. Check that the multimeter reads 5.0 volts.
5.
Then connect the multimeter between measure-
ment points 2-4. The voltage should be about 0.5 V.
Checking the function of oil temperature
1.
Disconnect the connector from the oil pressure
sensor.
2.
Connect 4-pin adapter 9998534 between the
sensor connector and multimeter 9510060-8.
3.
Measure with the multimeter set to measure resis-
tance between the measurement points of the
adapter.
The multimeter should show the following values:
Measurement points
Desired values
3–4
R~1.9 k
Ω
(20°C / 68°F)
3–4
R~ 0.1 k
Ω
(100°C / 212°F)
NOTE:
Even if resistance values follow those in the
above table, it is no guarantee that the sensor is fault-
free.
