Three Fault Codes at one time

[Guest]

Just recently my "Check Engine" light came on and when I check the code it presented three codes, 13, 15 and 23. I have the definitions to these three codes but am wondering if anyone has any idea what would cause all three of these codes at one time? 13 has to do with the Map sensor circuit, 15 with the distance sensor circuit and 23 with the charge temperature sensor circuit. I have checked the connector on all three units and the vacumme lines and find nothing visually unusual.

Any help in diagnosing the sourse of these three codes at one time will be much appreciated.

By the way - the engine is the 89 TC 2.2L EFI engine and except for a little idle stumble when one of these codes kicks on the check engine light, the engine seems to run fine.

[Guest Stephen Lyons]

Well, Fred, you're certainly right, those three items are hardly linked to each other, & you've certainly done the right thing by checking the electrical & vacuum connections first, which can quite easily cause a trouble code to pop up. With three at once coming on like this, though, I am wondering if you don't have some sort of glitch developing in the Single Module Engine Controller (SMEC). I emphasize that's just a semi-educated guess on my part for the next direction to look, not a definitive diagnosis by any means.

I should backtrack just a bit here, though. I presume you have cleared the codes by disconnecting the battery, and the same three codes come up right away again? If not, you may be seeing old malfunctions that stay in to be read, even after the any fix has been made. If you clear these out, & just one comes back up, my thought above probably has no validity whatsoever. You could then zero in on just that one device being a problem for some reason.