Off-Road and Agriculture
These videos demonstrate how to use PicoScope to diagnose problems in off-road vehicles such as front-end loaders, excavators, and bulldozers.
Also see our J1939 video on our CAN bus page
Diagnose Engine Health Fast
Accessing the engine on off-highway machinery can be a nightmare. In this video, we show you how to perform a non-intrusive engine health check using the WPS500 Pressure Transducer included in the Expert Kit. By analysing exhaust gas pulsations, you can assess combustion, compression, and fuel delivery without stripping the engine.
Key Diagnostic Techniques Covered:
- Setup & Calibration: How to connect the WPS500 using the exhaust adapter, select Range 3 (low pressure), and zero the sensor for accurate readings.
- Signal Correlation: We demonstrate why you should keep your Cam, Crank, and Injector (Cylinder Sync) channels active. This allows you to correlate exhaust anomalies with specific cylinders.
- Waveform Manipulation: Learn how to fix common setup errors in the software, such as inverting a current clamp that was connected backward and using the Zero Offset feature.
- Scaling for Detail: Exhaust pressure changes can be subtle. We show you how to use the Scale/Offset controls (pinching and dragging) to magnify the waveform and reveal the definition needed to spot faults.
- Interpreting the Data: Understand what a uniform exhaust pattern looks like and how this single test can point you toward cylinder leakage, valve train issues, or misfires.
Hydraulic Diagnostics: Flow Meter Setup
In this tutorial, we take a look at hydraulic diagnostics for off-highway, agricultural, and marine machinery using a Webtec flow meter and PicoScope.
Key Diagnostic Techniques Covered:
- Flow Meter Setup: Learn how to connect the pressure, flow (Q), and temperature (T) outputs to your oscilloscope.
- We also cover the essential step of inputting the flow meter's K-factor (pulses per litre) into the software to ensure accurate conversions.
- Safe Loading Practices: Discover why you must always ensure the flow meter's loading valve is completely unwound and open before starting the machine to prevent unexpected pressure spikes and system damage.
- Generating P-Q Curves: See how to use the X-Y view in the software to plot hydraulic pressure against flow. Watch as we slowly close the loading valve to increase system pressure and evaluate the pump's performance curve in real-time.
- Engine vs. Hydraulics Correlation: Is it a weak pump or a weak engine? By adding a crankshaft sensor to the test, we create a Math Channel to monitor engine RPM during the test. This proves whether the engine can maintain its speed under the maximum hydraulic load, quickly pointing you toward the root cause of performance issues.
- Temperature Monitoring: Understand why monitoring hydraulic oil temperature is critical for ensuring consistent and accurate periodic efficiency tests.
1: Introduction to PicoScope Off Highway Diagnostics
Six videos on Off-Highway Diagnostics with PicoScope.
The first is an introduction to PicoScope Off-highway Kits being used to diagnose a range of common problems found with Off Road machinery. See the PicoScope Off-Highway Kits for more details and pricing on the kits from Garage Lube.
Running time: 47min 33sec.
2: Diesel Diagnostics (Part 1)
PicoScope being used to diagnose problems with diesel engines in off-road vehicles (Part 1). Firstly, we look at injector current and voltage waveforms.
Secondly, we test of a Denoxtronic system operation and shutdown. During shutdown, the 'adblue' fluid is automatically withdrawn from the system to prevent freezing.
Running time: 22min 45sec.
3: Diesel Diagnostics (Part 2)
PicoScope being used to diagnose problems with diesel engines in off-road vehicles (Part 2).
Misfire!
The first test is misfire detection. In the guided test a camshaft sensor was used. this has been replaced by a current clamp measuring injector current as a cylinder identifier. The crankshaft sensor, the current clamp measuring injector current combined with fuel rail pressure are examined.
The crank speed is calculated using a maths channel. Notice how the engine accelerates as each cylinder fires. Any missing 'accelerations' indicate a misfire.
Learn how to reduce sensor noise by filtering and appropriate grounding. Notice the difference between the guided test crank signal vs the hall effect sensor in the vehicle under test.
J1939 CAN
The second test shows you how to analyse a CAN network in an off-highway vehicle. Also see our CAN Bus Testing and Decoding Videos for more on this subject. Note that off-road vehicles typically use J1939 protocol as opposed to cars that use J2534. This test highlights the differences between the protocols. J1939 which is very standardised, when properly understood and decoded, can assist you in identifying problems. PicoScope now has a J1939 Decoder.
Here is a link to isobus.net mentioned in the video which lists standard Source Addresses and PGNs.
Running time: 32min 29sec.
4: Hydraulics Testing
PicoScope being used to diagnose problems with hydraulics in off-road vehicles.
Running time: 32min 29sec.
5: Preventative Maintenance
PicoScope being used for Preventative Maintenance (PM) in off-road vehicles.
Running time: 22min 28sec.
6: Hydraulic Testing
PicoScope being to test hydraulics in off-road vehicles. Ben starts by testing hydraulic pressure using a WPS600S whilst monitoring crank-shaft speed. He shows how the engine speed changes with variations of hydraulic load and uses the high speed capability of the WPS600S pressure sensor to monitor hydraulic pump pressure pulsations.
Jon and Ben then discuss Pico flow-meters (please contact us if you are interested in these flow-meters). The WPS600S and a flow-meter are applied to testing hydraulic pumps, viewing the PQ curve in XY mode to plot the relationship between flow and pressure using the flow-meter's built-in restrictor, which creates a hydraulic load. The flow-meter also measures the temperature of the oil and as load is applied, the temperature increases.
Ben uses Pico to diagnose a simple fault on an old Kubota Mini Digger where the customer complained of limited hydraulic power. Ben used an optical sensor to measure crank-shaft speed. Hydraulic pressure was lower than expected.
Running time: 33min 50sec.