I'm thinking about situation like this:
when I do the self diagnostic procedure- the service checked connector is jumped and there is no errors in my car

the check engine shoud stay still on
or it shoudl stay off?

civic 94 d16z9

 

You jump the service connector while the car is off, turn it on and wait for codes

if no codes come up the ECU isn't seeing any problems. If it does come up with a code then refer to this


https://honda-tech.com/zerothread?id=1171263

 

I know how to do the self diagnostic and how to read the codes

but what about the situation when I jump the service connector and the check engine light stay still on?

is it correct?
check engine shouldn't stay off?

 

On my '95 Integra, with no codes stored, the CEL comes on solid when you jumper the connector. For example when checking spark timing...

If the CEL doesn't come on at all (after ruling out a burned-out bulb) that's code zero, which is supposed to be a fried ECU.

 

On my 99 Civic, the CEL behaves the same way as Jim describes.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by EE_Chris &raquo;</TD></TR><TR><TD CLASS="quote">On my 99 Civic, the CEL behaves the same way as Jim describes.</TD></TR></TABLE>
All obd1 and obd2 models do the same.