New Holland Workmaster 50, Service Manual

Page: 880 / 1067

Electrical systems - FAULT CODES
DTC 238-03-Oil pressure switch active with engine off
Control Module : ECU
Context:
The Engine Control Unit (ECU) A-9000 monitors the oil pressure switch S-9016 for proper operation. The oil pressure
switch S-9016 changes from its off to on state between
0.6 - 0.9 bar ( 8.7 - 13.0 psi ). If the oil pressure switch S-9016
does not return to its off state, once the engine is switched OFF, this fault will occur.
Cause:
The ECU A-9000 has sensed that the oil pressure switch S-9016 did not return to its off state.
Possible failure modes:
1. Faulty oil pressure switch S-9016, failed internally.
2. Faulty oil pressure switch S-9016 circuit wiring, open circuit.
3. Faulty ECU A-9000, software.
Solution:
1. Verify that the 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. Check the condition of the oil pressure switch S-9016.
Disconnect the engine harness (EN) from the oil pressure switch S-9016 at connector X-9016 .
Use a multimeter to check for continuity on the component side :
From To Value
X-9016 pin 1 chassis ground There should be continuity.
A. If there is continuity, leave connector X-9016 disconnected and continue with Step 3 .
B. If there is no continuity, the oil pressure switch S-9016 has failed internally, replace the oil pressure switch
S-9016.
3. Check the oil pressure switch S-9016 circuit for an open circuit condition.
Carefully disconnect the engine harness (EN) from the ECU A-9000 at connector X-9001 .
Place a jumper wire between connector X-9001 pin A06 and chassis ground.
Use a multimeter to check for continuity on the engine harness (EN) side :
From To Value
X-9016 pin 1 chassis ground There should be continuity.
A. If there is no continuity, there is an open circuit in the oil pressure switch S-9016 circuit. 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.
4. Visually inspect the relevant harnesses and connectors for damage, bent or dislocated pins, corroded terminals,
or broken wires.
Verify that the connectors are fully installed.
Flex the harnesses involved to reveal intermittent breaks or shorts in the wiring concerned.
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