PID Archives - Transmission Digest
Using Parameter Identification Data to Diagnose

I recently fixed an intermittent problem on an FNR5 transmission in a 2006 Mazda 3. The shop that brought it to me had been trying unsuccessfully for the past six weeks to fix it. When I called to inform them that it was fixed, they asked how I was able to fix in such a short time what they had not being able to do in weeks.

That question is what prompted me to write this article, not because I believe I’m in any way more intelligent than the average transmission diagnostician but because of the approach I used that allowed me to find the intermittent problem.

Analyzing Data Helps Solve Complicated Problems

With the addition of parameter identification data (PID), we can combine data with our knowledge of the way a transmission is designed to work and use it as a form of X-ray that permits us to see inside the transmission, so to speak. Let us use the following example to illustrate this.