New Holland CX720 Repair Manual page 2258

E0152-05-Coolant Temp / Fuel Filt Line Disconnected (B.50.A.95.90
- G.30.B.50)
CX720 Series 1282 - 1347, CX720 Series 1238 - 1281, CX740 Series 1282 - 1347, CX740 Series 1238 - 1281, CX760 Series 1282 - 1347, CX760 Series
1238 - 1281, CX780 Series 1282 - 1347, CX780 Series 1238 - 1281, CX820 Series 1282 - 1347, CX820 Series 1238 - 1281
E0152-05 - Coolant Temp / Fuel Filt Line Disconnected
NOTE: This troubleshooting chart is for CX combines Series 1238 and above.
Cause:
The coolant temperature sensor (B-31) circuit is open. (NH7.5 L Mechanical Engines Only)
Possible failure modes:
1. Sensor supply or ground wiring is open.
2. Controller internal failure (internal regulator failure).
Solution:
1. Enter the InfoView monitor - "Diagnose info" screen.
Select "Engine" sub menu.
Select "Coolant Temp / Fuel Filt" and check voltage range.
The proper voltage range is 0.5 - 4.9 volts.
A. If the voltage reading is high out of range (4.9 - 5.2 volts), continue with Step 2.
B. If the voltage reading is within the proper limits, continue the troubleshooting at step 7.
NOTE: Visually inspect the wiring harness and connectors. Verify that the connector was fully installed. Inspect
the terminals and wires at the connector for pushed back or corroded terminals or damaged wires. Flex the
harnesses involved to reveal intermittent breaks or shorts in the wiring concerned.
2. The voltage reading on the Infoview monitor is high (4.9 - 5.2 volts). Disconnect the coolant temperature sensor
connector X310. Use a jumper wire to short connector X310 pin B to chassis ground.
A. If voltage drops to less than 0.5 volts, the open circuit is not in the supply side of the circuit. Continue with
step 4.
B. If the voltage remains high, continue with Step 3.
3. The voltage reading on the Infoview monitor is high (4.9 - 5.2 volts). Disconnect the engine harness from the
main frame harness at connector X010. Use a jumper wire to short connector X010 pin 18 to chassis ground.
A. If voltage drops to less than 0.5 volts, the open is in the engine (EN) harness between connector X010 pin
18 and coolant temperature sensor connector X310 pin B wire 429 yellow. Locate the open and repair.
B. If voltage remains high, the open is in the main frame (MF) harness between connector X010 pin 18 and
connector X016 pin J2-24 wire 429 yellow. Locate the open and repair.
4. Disconnect the coolant temperature sensor connector X310. Use a multimeter to check for continuity between
the harness end of connector X310 pin A and chassis ground.
A. If there is continuity, the ground path for the sensor is complete, and the fault is in the sensor itself. Replace
the sensor.
B. If there is no continuity to ground, the ground path for the sensor is open. Continue with step 5.
5. Disconnect the engine harness from the main frame harness at connector X010. Use a multimeter to check for
continuity between the harness end of connector X010 pin 14 and chassis ground.
A. If there is continuity, the open circuit is in the engine (EN) harness between connector X010 pin 14 and
connector X310 pin A wire 852 blue or 468 blue. Locate the open and repair.
B. If there is no continuity to ground, continue with step 6.
POWER PRODUCTION - ENGINE COOLANT SYSTEM
2 4/7/2006
B.50.A / 68