New Holland WorkMaster 50 Service Manual page 776

DTC 159-02-Fuel metering unit has an open load error
Control Module : ECU
Context:
The Engine Control Unit (ECU) A-9000 monitors the fuel metering unit Y-9000 signal circuit. If the ECU A-9000 detects
an open load error in the fuel metering unit Y-9000 signal circuit, this fault will occur.
Cause:
There is open load detected in the fuel metering unit Y-9000 signal circuit.
Possible failure modes:
1. Faulty fuel metering unit Y-9000 wiring, open circuit.
2. Faulty fuel metering unit Y-9000, 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 4.
2. Test the fuel metering unit Y-9000 internal resistance.
Disconnect the engine harness (EN) from the fuel metering unit Y-9000 at connector X-9007.
Use a multimeter to measure the resistance on the fuel metering unit Y-9000 pins :
From
X-9007 pin 1
A. If there is between 2.6 - 3.2 Ω, leave connector X-9007 disconnected and continue to Step 3.
B. If there is not between 2.6 - 3.2 Ω, the fuel metering unit Y-9000 has failed. Replace the fuel metering unit
Y-9000.
3. Check the fuel metering unit Y-9000 engine harness (EN) wiring for an open circuit.
Disconnect the engine harness (EN) from the ECU A-9000 at connector X-9001.
With the key in the OFF position, use a multimeter to perform the following continuity check on the engine harness
(EN) side :
From
X-9007 pin 1
X-9007 pin 2
NOTE: Wiggle the harness during the check to promote an intermittent electrical connection.
A. If there is no continuity, there is an open circuit condition in the fuel metering unit Y-9000 engine harness (EN)
wiring. Locate and repair the broken conductor.
B. If there is continuity, check the ECU A-9000 for the appropriate software and re-flash, if necessary.
Electrical systems - FAULT CODES
To
X-9007 pin 2
To
X-9001 pin A60
X-9001 pin A15
47866583_ 02/12/2015
55.12 [55.DTC] / 55
Value
There should be between 2.6 - 3.2 Ω
at approximately 20.0 °C (68.0 °F).
Value
There should be continuity.
There should be continuity.