Hi all.. I've recently had To put a new timing cover on as it was cracked, on another post of mine someone said something about a relearn for the crankshaft position sensor must be performed.. Anyway I've rang round a million places and no one has a clue so I just drove it as it seemed fine as it was But.. I had a bad leak coming from the Crankshaft position sensor itself so I've had to change that too and now it's not running the same, it runs and drives fine but I can tell its not as it should, no where near as responsive as it was. So I really need someone in the UK with equipment capable of the relearn. Any ideas???.

Also, the EML was on initially until I topped the oil up then it went off for around an hour then came back on, I desperately need someone with equipment or ill end up flogging it and I really don't want to as its a beauty to drive.

Thanks

 

You're right about the relearn. If the crankshaft position sensor or timing cover is moved, removed, replaced, or disturbed in any way, the crankshaft position sensor relearn must be performed. The relearn is also necessary if the PCM is replaced. It can only be done with a scan tool capable of initiating the relearn. With the scan tool connected, and the relearn initiated on the tool, manually bring the engine to 4K RPM. At that point the scan tool takes over RPM control and performs the relearn, then drops RPM back to idle and the procedure is complete. Once initiated, it takes less than 3 seconds to complete.

The crank sensor is "aimed" at the tone ring inside the timing cover. I'm sure you saw it with the timing cover removed.




The sensor has a very small area that it is focused to. Each sensor is unique in where its focus area is. If the timing cover or sensor move, so does the focus area. That's why the relearn needs to be done. When the crankshaft rotates, the tone ring windows pass the sensor and a signal is generated and sent to the PCM, (Powertrain Control Module). The relearn "teaches" the PCM exactly where the sensor is focused in relation to the windows when they pass the sensor. The relearn data is burned to a memory file in the PCM and remains there until the next relearn.

 

Thank you very much for that, would there be a problem if I have put too much oil in. Would that make the engine management light come on?

 

A professional grade OBD-II scanner can do it. The shop where I did mine had a unit made by Snap-On. The guy who worked there was cool and let me do it while he worked on another car. The procedure was simple and involved scrolling through a few menus to get to it, then following the prompts on the unit.

A GM dealer would definitely be able to do it, but it may cost a bit more.

AFA, excess oil... How much excess? A little bit over full will not cause problems, but if you put in way too much it could blow out through the PCV system and back into the intake, causing smoke, misfires and other issues that will make the SES light come on.