Case IH AFX8010 Repair Manual page 1053

Sensing system Coolant temperature - Incorrect value (B.50.A.95.90
- G.30.C.10)
AFX8010
E0399-02 - Coolant Temperature Sens
Cause:
Signal range outside threshold limits
Signal not plausible or intermittent fault
Possible failure modes:
Effect on Engine: Engine enabled - no restriction on fuel or speed
1. Faulty coolant sensor
Faulty connector or wiring
2.
Solution:
1. Check the engine Coolant level.
A. Ensure the coolant level is within the min/max indicators. Adjust as required. If the level was very low,
ie, no fluid visible in the header tank, investigate the cause of the fluid loss and repair. Remove the
fault code from the ECU memory, using the electronic service tool and operate the engine, if the fault
does not reoccur, continue with vehicle operation.
B. If the fault reoccurs, continue with step 2.
2.
Check connector X373 at coolant temp sensor B44.
A. Ensure the connector X373 is not damaged, the terminals are in the correct position in the housing, and
that the fit is tight on the sensor. Repair or replace damaged components as required.
B. If the connector is okay,continue with step 3.
3. Check coolant temp sensor B44.
A. Remove the connector X373 and check the sensor using a suitable multi-meter. Measure the resistance
across the sensor terminals, the resistance should vary between 8 - 10 kOhms @ -10 °C, 2.2 - 2.7
kOhms @ 20 °C, and 0.29 - 0.36 kOhms @ 80 °C, . Check for a short to ground between each sensor
terminal and the engine block, an open circuit should be recorded on each terminal. If any readings are
incorrect replace the sensor.
B. If the sensor is okay continue with step 4.
4. Check wiring.
A. Disconnect the sensor connector X373. With the keystart switch ON, measure the voltage at pin
1 (pink wire), +5 volts should be measured. If no voltage is measured check the wiring for continuity
between Pin 1 of the sensor connector X373 and pin 5 of engine ECU connector X192X192. Repair
wiring as required. Check for voltage on Pin 2; 0 volts should be measured. If voltage is measured
trace and repair short circuit in wiring between Pin 2 of the sensor connector X373 and Pin 22 of the
engine ECU connector X192. With the keystart OFF, also check for continuity of the wire between
Pin 2 of the sensor connector X373 and Pin 22 of the engine ECU connector X192, and for a short
to ground. Trace fault and repair as required.
B. If the wiring is okay suspect a faulty engine ECU. Download engine software using the electronic service
tool and operate engine. If fault still occurs substitute engine ECU.
POWER PRODUCTION - ENGINE COOLANT SYSTEM
9675 1 27/05/2004
B.50.A / 45