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I have a P0500 (Vehicle Speed Sensor Circuit Error) on this van.
It has a two wire active speed sensor with a 12v power feed.
The sensor, power and return cables all check out fine. However there is about 800mv worth of ripple/noise in the power feed. Power feed comes from the ECU and that noise is happening right at the ECU. Interestingly, the noise on the power feed from the DLC is considerably less.
This is a JDM vehicle and no service information is available so testing ECU powers and grounds is a little tricky.
My question to you guys is, do you think 800mv worth of noise in the power feed to the sensor is enough to make the sensor glitch out and cause the P0500?
I am pretty sure I can see the glitch, but only had my little handheld scope at the time. It's a periodic complete jump in the square wave.
Alll thoughts and help very very much appreciated!
Last edit: 2 years 4 months ago by Kiwi Alex. Reason: Typo
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