CEL appear and disappearing

cre · 05-17-2012, 06:23 AM

Code 51 won't cause the check engine light to appear under except while the ECU is in diagnostic mode. Improper TPS calibration will not cause a code 41 either.

Have you tested the wire harness? I would inspect and clean the ECU grounds and grounds from the battery. Test the alternator. Test the Vc pin at the ECU, the TPS, and the AFM connector; It should read 4.8v or so when the ignition is in the "on" position.

The ECU is still a possibility but unless you've got a known good one you can swap in to test with I wouldn't spend money on one without testing as much as possible first... Start with the cheap stuff or this car will sink you financially.

EDIT: Clear codes by removing the EFI fuse in the engine bay fuse box for 10 seconds or more.

05-17-2012, 06:23 AM	#25
cre Toyota Racing Development Join Date: Apr 2007 Posts: 5,038	Code 51 won't cause the check engine light to appear under except while the ECU is in diagnostic mode. Improper TPS calibration will not cause a code 41 either. Have you tested the wire harness? I would inspect and clean the ECU grounds and grounds from the battery. Test the alternator. Test the Vc pin at the ECU, the TPS, and the AFM connector; It should read 4.8v or so when the ignition is in the "on" position. The ECU is still a possibility but unless you've got a known good one you can swap in to test with I wouldn't spend money on one without testing as much as possible first... Start with the cheap stuff or this car will sink you financially. EDIT: Clear codes by removing the EFI fuse in the engine bay fuse box for 10 seconds or more. __________________ 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 ---> Last edited by cre; 05-17-2012 at 06:25 AM.