New Holland WorkMaster 50 Service Manual page 765

DTC 143-04-Camshaft speed sensor pattern is not plausible
Control Module : ECU
Context:
The Engine Control Unit (ECU) A-9000 monitors the camshaft position sensor B-9017 characteristics for angle, speed
determination, signal plausibility, and quality. If the ECU A-9000 determines that the camshaft signal does not match
the expected pattern (edge, distance, level) or not all expected camshaft edges are detected during an engine revo-
lution, this fault will occur.
Cause:
The ECU A-9000 has detected a camshaft pattern signal error.
Possible failure modes:
1. Faulty camshaft position sensor B-9017 wiring.
2. Faulty camshaft position sensor B-9017, improperly seated or mounted.
3. Faulty camshaft position sensor B-9017, internal failure.
4. 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 6.
2. Check the physical integrity of the camshaft speed sensor B-9017. The sensor should be fully seated and mounted
tightly.
A. If the sensor is not mounted/secured properly, repair as necessary.
B. If the sensor is not damaged and is mounted/secured properly, continue to Step 3.
3. Check the camshaft position sensor B-9017 wiring in the engine harness (EN) for an open circuit.
Disconnect the engine harness (EN) from the camshaft position sensor at connector X-9008.
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-9008 pin 2
X-9008 pin 1
X-9008 pin 3
A. If there is continuity, leave connectors X-9008 and X-9001 disconnected and continue to Step 4.
B. If there is no continuity, there is an open circuit in the camshaft position sensor B-9017 wiring. Locate and
repair the broken conductor.
4. Check the camshaft position sensor B-9017 wiring in the engine harness (EN) for a short circuit.
With the key in the OFF position, use a multimeter to perform the following continuity check on the engine harness
(EN) side :
Electrical systems - FAULT CODES
To
X-9001 pin A28
X-9001 pin A14
X-9001 pin A13
47866583_ 02/12/2015
55.12 [55.DTC] / 44
Value
There should be continuity.
There should be continuity.
There should be continuity.