New Holland WorkMaster 50 Service Manual page 759

DTC 141-02-Crankshaft speed sensor values are not plausible
Control Module : ECU
Context:
The Engine Control Unit (ECU) A-9000 monitors the crankshaft position sensor B-9007 characteristics for angle,
speed determination, signal plausibility, and quality. If the ECU A-9000 determines that there are no crankshaft posi-
tion signals detected for at least 4 engine revolutions, this fault will occur.
Cause:
The ECU A-9000 has determined that there is no crankshaft position signals detected for at least 4 engine revolutions.
Possible failure modes:
1. Faulty crankshaft position sensor B-9007, not fully seated or loose.
2. Faulty crankshaft tone wheel, damaged or misaligned.
3. Faulty crankshaft position sensor B-9007 wiring, short circuit.
4. Faulty crankshaft position sensor B-9007, internal failure.
5. 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 physical integrity of the crankshaft position sensor B-9007. The sensor should be fully seated and
mounted tightly.
Remove the crankshaft position sensor B-9007 and inspect the crankshaft tool wheel. The tone wheel should not
be damaged or loose.
A. If the sensor or tone wheel is damaged or is not mounted/secured properly, repair as necessary.
B. If the sensor or tone wheel is not damaged and is mounted/secured properly, continue to Step 3.
3. Check the crankshaft position sensor B-9007 wiring for a short circuit to battery condition.
Disconnect the engine harness (EN) from the crankshaft position sensor B-9007 at connector X-9039.
With the key in the OFF position, use a multimeter to perform the following voltage check on the engine harness
(EN) side :
From
X-9039 pin 2
X-9039 pin 1
A. If there is no voltage, leave connector X-9039 disconnected and continue to Step 4.
B. If there is voltage, there is a short circuit to battery in the crankshaft position sensor B-9007 engine harness
(EN) wiring. Locate and repair the shorted conductor.
4. Check the crankshaft position sensor B-9007 engine harness (EN) wiring.
With the key in the ON position, use a multimeter to perform the following voltage check on the engine harness
(EN) side :
Electrical systems - FAULT CODES
To
Chassis ground
Chassis ground
47866583_ 02/12/2015
55.12 [55.DTC] / 38
Value
There should be no voltage.
There should be no voltage.