New Holland WorkMaster 50 Service Manual page 865

DTC 225-03-Main relay stuck error
Control Module : ECU
Context:
The Engine Control Unit A-9000 controls the main relay K-9102. The main relay K-9102 is powered on by the ECU
A-9000 to achieve after-run. The main relay K-9102 is powered off once after-run is completed. If the ECU A-9000
determines that the main relay K-9102 is "stuck" or will not shut off as commanded, this fault will occur.
Cause:
The ECU A-9000 has determined that the main relay K-9102 will not shut off as commanded.
Possible failure modes:
1. Faulty main relay K-9102, wiring.
2. Faulty main relay K-9102, internal failure.
3. Faulty ECU A-9000, software.
Solution:
1. Verify fault is present and active.
Use the Electronic Service Tool (EST) to check the status of this fault.
A. If the fault is present and active, continue with Step 2.
B. If the fault is no longer present or in an inactive state, the fault may be intermittent and not currently active.
Continue with Step 7.
2. Check the main relay K-9102 coil for an internal failure.
Remove the main relay K-9102.
Use a multimeter to measure the resistance on the main relay K-9102 pins :
From
X-9129 pin 85
A. If there is approximately 70 - 130 Ω, leave the main relay K-9102 disconnected and continue to Step 3.
B. If there is not approximately 70 - 130 Ω, the main relay K-9102 has failed. Replace the main relay K-9102.
3. Check the main relay K-9102 low side driver wiring for a short to ground.
With the key in the OFF position, use a multimeter to perform the following continuity check for a short to ground
on the vehicle harness (VE) side :
From
X-9129 pin 86
A. If there is continuity, there is a short circuit in the main relay K-9102 wiring in the vehicle harness (VE). Use the
appropriate service manual, if necessary, to locate and repair the shorted conductor.
B. If there is no continuity, leave the main relay K-9102 disconnected and continue to Step 4.
4. Check the main relay K-9102 low side driver wiring for a short circuit.
Disconnect the vehicle harness (VE) from the ECU A-9000 at connector X-9102.
With the key in the OFF position, use a multimeter to perform the following continuity checks for a short circuit on
the vehicle harness (VE) side :
Electrical systems - FAULT CODES
To
X-9129 pin 86
To
Chassis ground
47866583_ 02/12/2015
55.12 [55.DTC] / 144
Value
There should be approximately 70 -
130 Ω.
Value
There should be no continuity.