Battery Voltage Filter, Shorted To Low Source - New Holland CX720 Repair Manual

0442.4-BATTERY VOLTAGE FILTER, SHORTED TO LOW SOURCE

(SERVICE TOOL FAULT CODE 18) (B.20.A.92 - G.30.B.53)
CX840
0442.4 - BATTERY VOLTAGE FILTER, SHORTED TO LOW SOURCE (SERVICE TOOL FAULT CODE 18)
Context:
Engine enabled - no restriction on fuel or speed
Cause:
Battery voltage is outside Signal Range Check.
Possible failure modes:
1. Battery fault
2. Engine ECU main relay (K-14) faulty
Solution:
1. Check fuses F-01 and F-38.
A. Replace fuse If blown. Remove the fault code from the engine ECU memory using the electronic service
tool and check the operation of the engine. If fuse blows again inspect wiring harness for damage.
B. If fuses are okay continue with step 2.
2. Check battery voltage.
A. If voltage is less than 9.5 Volts, check the battery and charging system . Ensure the battery has the correct
voltage and remove the fault code from the engine ECU memory using the electronic service tool. Operate
the engine, if the fault reoccurs continue with step 3.
B. If the voltage is greater than 9.5 Volts continue with step 3.
3. Check the Main Relay (K-14).
A. Remove the relay and check its operation. If okay continue with step 4.
B. Replace the relay if faulty. Remove the fault code from the engine ECU memory using the electronic
service tool. Operate the engine, if the fault reoccurs continue with step 4.
4. Check the wiring harness.
A. Remove relay K-14 and check for continuity of the wiring between the engine ECU connector X193 and
the relay K-14 holder. Check between pin 2 of the holder and pin 27 of X193 and between pin 5 of the
holder and pins 3 and 4 of X193. If an open circuit is indicated at any stage repair or replace the wiring as
required.
B. If continuity is good remove the fault code from the ECU memory, using the electronic service tool and
operate the engine. The fault may be intermittent, wiggle test the harness to attempt to induce the fault. If
fault reoccurs repeat step 4. If fault does not occur continue with vehicle operation.
Series 1348 and above
Wiring harness - Electrical schematic frame 02 (A.30.A.88-C.20.E.02)
Series 1206-1347
Wiring harness - Electrical schematic frame 03 (A.30.A.88-C.20.E.03)
Series 1206-1347
Wiring harness - Electrical schematic frame 24 (A.30.A.88-C.20.E.24)
Series 1348 and above
Wiring harness - Electrical schematic frame 29 (A.30.A.88-C.20.E.29)
POWER PRODUCTION - FUEL AND INJECTION SYSTEM
2 4/7/2006
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