: P056 easy fix



Ken Seliga
07-27-04, 03:05 PM
Recently my 95 Eldorado started randomly setting the SES light, diags showed the stored code was P056 ( Transaxle speed sensor)..I searched Cadillac Forums and the factory manual..What I found was that the signal from the transaxle is very sensitive to electrical interference (EMI). Eldy had never shown this code before so I didn't think it was the sensor.and it all started in a heavy rain. P056 would randomly set, but mostly on start-up. Investigation showed that the number 1 plug wire was laying on the harness below it..That harness carries the ckt 1230 and 1231(C129) signal from the transaxle to the PCM. I had changed the plugs about 2 weeks before this started..This time I re-routed the rear plug wires ( 1 at a time ) over the harness that carries the plug wires to the front 4 cylinders...this raised the rear plug wires above the harness..Viola...P056 fixed.. Lessson 1... Not all problems are bad or expensive...Lesson 2 Old electronic/programmers adage...IF SOMETHING USED TO WORK AND NOW DOESN'T....GO BACK TO THE LAST CHANGE YOU MADE!!!!!!!!!!!!!!!!

Ken Seliga
12-01-05, 01:48 PM
I was wrong ..the problem got progressively worse, until I ended up changing the trans input speed sensor...see my post of 12-01-2005 for the dreaded p056 code..sorry