Main Relay Defect, Data Incorrect; Cx840, Cx860, Cx880 - New Holland CX720 Repair Manual

0393.2-MAIN RELAY DEFECT, DATA INCORRECT (SERVICE TOOL
FAULT CODE 199) (B.20.A.91.21 - G.30.C.10)

CX840, CX860, CX880

0393.2 - MAIN RELAY DEFECT, DATA INCORRECT (SERVICE TOOL FAULT CODE 199)
Context:
Engine enabled - no restriction on fuel or speed
Cause:
Defective main relay (K-14) - not switching off
Possible failure modes:
1. Faulty relay
2. Fault in wiring harness
Solution:
1. Replace relay K-14
A. Remove the fault code from the engine ECU using the electronic service tool. Check the operation of the
engine. If the fault reoccurs continue with step 2.
2. Check wiring between relay K-14 and engine ECU. (Short to low source)
A. ENSURE THE KEYSTART SWITCH IS OFF. Remove relay K-14 and disconnect the connectors from the
engine ECU (A-01). Using a suitable multi-meter, check for a short to ground at pin 27 of X193. If no short
to ground is indicated continue with step 3.
B. If a short to ground is indicated, disconnect connector X010, if a short to ground is still indicated trace and
repair the wiring between the engine ECU (A-01) and connector X010.
C. Continue to trace the short to ground at the female side of connector X010. Disconnect connector X004
and check for a short to ground at X010 pin 26. If a short is indicated repair the wiring between connectors
X010 and X004. If no short is indicated here then the short to ground must be between the male side of
connector X004 and holder of relay K-14.
3. Check wiring between relay K-14 and engine ECU. (Short to high source)
A. Remove relay K-14 and disconnect the connectors from the engine ECU (A-01). Using a suitable multi-
meter check for a short to +12 Vat pins 3 and 4 of X192. If no short to +12 Vis indicated continue with step
4.
B. If a short to +12 V is indicated, disconnect connector X010, if as short to+12 Vis still indicated trace and
repair the wiring between the engine ECU (A-01) and connector X010.
C. Continue to trace the short to +12 Vat the female side of connector X010. Disconnect connector X004
and check for a short to +12 Vat X010 pin 28. If a short is indicated repair the wiring between connectors
X010 and X004. If no short is indicated here then the short to +12 V must be between the male side of
connector X004 and holder of relay K-14.
4. Check for good connections onto engine ECU and at connectors X004 and X010. Check main Engine ECU
relay, K-14, for correct operation. Remove the fault code from the ECU memory using the electronic service
tool. Operate the engine, the fault may be intermittent, wiggle test the harness and operate other functions to
attempt to induce fault. If fault reoccurs return to step 2. If fault does not occur continue with vehicle operation.
A.
Series 1348 and above
Wiring harness - Electrical schematic frame 02 (A.30.A.88-C.20.E.02)
Series 1206-1347
POWER PRODUCTION - FUEL AND INJECTION SYSTEM
2 4/7/2006
B.20.A / 114