Additional EScope Screen Shots 2
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2: This waveform was taken at the fuel pump relay (power side of fuel pump) with a current clamp after fuel had been added to the empty fuel tank. Note the Freq (Hz) is 79.26 and multiply this by 60 sec. to find the RPM of the fuel pump was 4755.6 RPM.
1: This vehicle was towed in with a no start. When the fuel pressure was tested there was only 5PSI. The fuel gauge had a reading of ¼ tank. The fuel pump current was the next test. The amp clamp was placed at the fuel pump relay. Note the Freq (Hz) is 152.91 and multiply this by 60 sec. to find the RPM of the fuel pump was 9174.6 RPM. This fuel pump was rotating too fast. Possible causes are no fuel in the tank or the fuel pump had separated from the electric motor.
3: This 2002 Nissan MAF sensor had failed causing low power and DTC PO171. This sensor was out of range by 20% which is a very large amount. The signals under the MAF signal are the four O2 sensor signals. Note: The MAF signal was intercepted by the EScope and modified.
4: This Cadillac had multiple shorted injectors. The top screen shows the voltage waveforms. The bottom screen shows the Amp clamp waveforms for three injectors. The two shorted injectors are the white trace and the blue trace. The purple trace is a good waveform.
5: This shows the crank sensor in red, the rectified RPM signal in yellow and the EST signals in blue and green.
6: This GM vehicle was still running and came into the shop for an intermittent stalling problem. The vehicle never stalled but the problem was found using an Amp clamp on the power wire to the fuel pump.
7: These signals are during cranking. The yellow and red traces are distributor timing signals. The green trace is the coil primary. The blue trace is the ASD primary or control side of the relay. The white trace is the secondary side of the ASD relay. The purple trace is the signal from the logic module to the power stage for the module.
10: This shows the front and rear O2 sensor signals. The yellow and red traces are the front O2 sensors. The green and blue traces are the rear O2 sensor signals.
9: This signal is from a Windstar van. The yellow trace is the CAM sensor signal. The red trace is the crank sensor signal.
11. This vehicle was cutting out. The yellow trace is the MAF signal, red trace is the 12V power, and green trace is ground.
12. This stacked chart shows the timing signals and the injector waveforms. Note the injectors are out of sequence and the orange trace shows 50ms of on time. This is a logic problem in the PCM.
 
 
 
 

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