CEL appear and disappearing

cre · 04-26-2012, 11:29 PM

Could be knock. Not all runtime errors are recorded and from what I understand some require a certain threshold to be surpassed in any given instance before it's recorded. There is no code for "OMG there's a hole in the #1 piston and your rods are a knockin!". You can try driving around with the diagnostic mode set and see if any additional codes show up. Naturally there will be a code 51.

Power loss at the ECU to the point of clearing the codes is a possibility but usually this isn't consistent and you'll see a code for inconsistent power show up sooner or later.

Code 51 is just indicative of the IDL switch being open the A/C circuit reporting as "on" and it clears as the trigger condition is resolved. So, it'll show up it you step on the throttle, have the A/C on or the TPS is misaligned but once the condition is remedied it'll go away after a few seconds.

04-26-2012, 11:29 PM	#2
cre Toyota Racing Development Join Date: Apr 2007 Posts: 5,038	Could be knock. Not all runtime errors are recorded and from what I understand some require a certain threshold to be surpassed in any given instance before it's recorded. There is no code for "OMG there's a hole in the #1 piston and your rods are a knockin!". You can try driving around with the diagnostic mode set and see if any additional codes show up. Naturally there will be a code 51. Power loss at the ECU to the point of clearing the codes is a possibility but usually this isn't consistent and you'll see a code for inconsistent power show up sooner or later. Code 51 is just indicative of the IDL switch being open the A/C circuit reporting as "on" and it clears as the trigger condition is resolved. So, it'll show up it you step on the throttle, have the A/C on or the TPS is misaligned but once the condition is remedied it'll go away after a few seconds. __________________ If something breaks or you need to contact a member of the administration please post HERE. Unless it's a private or administration matter please post it on the forum. It benefits no one else if car related questions aren't posted for future users and takes away from the time I'm able to spend helping on the rest of the forum. If you're so inclined I'm always more than happy to accept tips via PayPal. Tip Jar --->