OK I just picked up a CRX SI and I got the check engine on this morning so when I went to check the cell codes I noticed that the red light was already flashing with no jumper. Even when I put in a jumper it did not flash any different. Just keeps flashing it looks like a code 1 O2 sensor. After I turned off the car the check engine light went off but the ECU keeps flashing. Anyone ever have this issue? Video posted below.

https://www.youtube.com/watch?v=iVV2...ature=youtu.be

 

Obd0 ecu is always in test mode so that's normal if you have a code

 

ok thats good, now i need to figure out why when i put in the jump wire I get no codes flashing. If i track back those two wires where are they suppose to land?

 

the service connector on the OBD0 is only jumped for setting the ignition timing, not for checking codes - reset the ECU and the codes will go away until the next time the Check Engine Light comes on - when you get a Check Engine Light, the codes are stored in the ECU and remain there until you physically reset it - when you turn the ignition off the Check Engine light will go off and stay off until another (or the same) problem is detected by the ECU

 

So how do I pull the cell codes then? I thought it was like the obd1 with the jumper

 

just look at the red LED on top of the ECU like in your video and count the number of flashes - if it has just one code as you seem to have (code 1) it will flash, pause, flash, pause flash, etc. - if you have more than one code it will flash a code for the first problem, pause, flash the code for the next problem, pause, and so on - when it gets to the last code, it will pause and start over - to give you a better understanding of how it works, unplug your IACV connector and start it up - you should get a check engine light - if you haven't reset the ECU, you should see it flash once for the O2 sensor and 14 times for the IACV

these are the codes for the OBD0 D-series ECUs

 

Oh cool thanx so no jumper is needed