imported_martiniracing

i have a 1990 crx dx.. the motor is jdm 1.5 single cam. the check engine light would come on about 5 minutes of driving (from cold engine) and stays on. i have jumped the diagnostic plug, turned the key on to ON position, but it throws no codes. any suggestions?

sam

zeeman

iTrader: (1)

when the CEL comes on, move the carpet on the passenger side (near the firewall) to reveal the ecu, the light on the ecu will blink.

imported_janz3n

unless his jdm motor is obd1

zeeman

iTrader: (1)

doesn't matter if the engine is obd1, it matters if the ecu is obd1.
If your converted to obd1, then you'll need to wire a switch to ground from one of the pins on the ecu in order to make the CEL light flash to read the code.
If the ecu is obd0, there will be a little red light on the ecu itself that will be flashing

imported_chris_v2

No man.. the motor obd matters..

lol

Do what Lenny said, a light on the ecu flashes on obd0's

imported_martiniracing

the ecu remain's obd0..

so do i jumper the diagnostic pin, turn key to ACC and then look for codes blinked from the ecu itself?

imported_chris_v2

I've only checked codes on an obd0 once.. and I don't remember jumping anything. Either way if its not flashing when the CEL is on then jump it..

imported_martiniracing

okay, on normal operation (no CEL) would the ecu light come on?

when ECU light does flash, is that the trouble code?

sam

imported_chris_v2

1) no

2) yes

imported_janz3n

ok.. i meant the ecu could be obd1 aswell as distributor and so on.. i didnt mean just the engine.. bla bla bla. and you can have an ecu code with no cel... i do code 20 but its cuz i have a 88-89 si ecu in a 90-91 sedan with mpfi swap. car runs fine.

imported_martiniracing

okay, i'll look into it, thanks

the car is all original besides the engine

imported_martiniracing

oh another question guys. on obd0, when i'm adjusting timing and have the jumper connected, would there be any indication from the cluster or the ECU that the car is in service mode (with all acessories off)?

sam

imported_janz3n

ok im not really familiar with this.. but i think you only jump the connector when you do timing with the distributor. and the thing about service mode and all acc. off iv never heard of.

imported_chris_v2

Not sure on obd0 but I assume the same rule applies on obd2's. THe CEL will hold steady if its in service mode (thats if you have no codes)