The sensors frequently read 0 and 23.5k as range and fail to read accurately in the middle. High or low pressrue test mean nothing as long as there are no codes. What problem though, sensor or actual rail pressure? How do you tell? Answer is you don't, if there is a question you swap in a new one beacuse there is no good way to validate that the sensor is reading correctly without some rather expensive equipment. If the ECU commands 15k and the sensor reads 12k, problem. Swapped it out and the new one was all good. This was repeatable 2x I was looking at it. Around 140~150*f (IIRC) it opened up, then around 170~175 it went back to normal. I have seen a coolant sensor fail while I was logging it during warmup. Assuming it is not either open or shorted.įWIW. The true way to test any sensor is to put a calibrated reference on the system and compare the cal'd standard vs the sensor under test and test multiple data points across the range of the sensor. I'm not sure how the sensor fails (what about it is failing, low or high pressure) but at least that should tell you something about the sensor. Also look at it at idle and see if that pressure makes sense or not. If it goes to the max range of the system then you at least know the upper range is still there. What may work is to put the scan tool on there, log the rail pressure and unplug the FCA for a second or two and see how high the measured rail pressure goes. If it asks for 15k and the sensor tells the ECM its at 15k the ECM will think it's fine.
the sensor it telling the ECM what it thinks the pressure is. Click to expand.Looking at commanded vs actual wont tell you if the sensor is bad.