Honda Civic Forum - '92 Civic VX has ECU Code 12 "EGR lift valve"?

Honda Civic Forum (https://www.civicforums.com/forums/)

- 1st - 5th Generation Civic 1973 - 1995 (https://www.civicforums.com/forums/184-1st-5th-generation-civic-1973-1995)

- - '92 Civic VX has ECU Code 12 "EGR lift valve"? (https://www.civicforums.com/forums/184-1st-5th-generation-civic-1973-1995/356452-92-civic-vx-has-ecu-code-12-egr-lift-valve.html)

'92 Civic VX has ECU Code 12 "EGR lift valve"?

My '92 Civic VX "CA(alifornia)" is intermittently displaying ECU Code 12 "Exhaust Gas Recirculation Lift Valve". I've been told it may not be a failed EGR valve, but rather some clogged runners. Is there a procedure for analyzing and addressing this issue someone can point me to?

Brian

Re: '92 Civic VX has ECU Code 12 "EGR lift valve"?

Quote:

Originally Posted by brians356 (Post 4646029)

A quick look into the code reveals my guess was close.

Quote:

Originally Posted by ezone (Post 4646028)

Without knowing or researching anything more about the EGR issue you have, I'd guess the valve did not open when the computer expected it to open. Mixed up and detached vacuum lines could be a likely cause, but certainly not the only possible cause.

Wow, the forum is working again. Thanks mods.

The code is unrelated to clogged EGR passages, it has everything to do with what value the computer did or did not see from the lift sensor (AKA position sensor) when the valve was supposed to be activated.

You are probably gonna need a shop manual if it's much deeper than vacuum hoses.

Re: '92 Civic VX has ECU Code 12 "EGR lift valve"?

I'm glad you mentioned vacuum lines, as some electrical wires were chewed by ground squirrels, according to the friend who sold me the car. (He replaced spark plug wires three times because of this.) It is not unlikely a vacuum line has been compromised. So may I assume the place to start is to inspect vacuum lines associated with the EGR? Or are there other lines not so obvious I need to check?

Re: Shop Manual: Do you mean full-on phone book-sized official Honda Shop Manual, or something like a Haynes'?

Brian

Re: '92 Civic VX has ECU Code 12 "EGR lift valve"?

Wires, hoses, everything. Be observant.

Learn how the system is supposed to work and learn what the computer uses to determine a failure.... that makes it much easier to figure out what's not working.

Your library may have access to Mitchell or Alldata online, maybe those would help.
I can't comment on any manuals, I have access to factory stuff.

EDIT: Sometimes even the factory info is vague and leaves much to be desired.