OBD2 showing no codes - How to show
 

I have been troubleshooting my 94 Volvo 850 Turbo Wagon and find that I am not able to read any codes off of the OBD2 diagnostic unit in the engine compartment. When I set the test lead in the A-6 pin location & press the test button, the LED comes up red for as long as I depress the test button but once released shows nothing. I have also tried the procedure for clearing codes (hold the test button down for five seconds) and still nothing.

I have the check engine light on and knew to replace the oxygen sensors(which I have done) and now want to take it in for an emmissions test but the check engine light is still on and I need it off to be able to be tested.

Any advice out there on this?
Signed, Troubled in Oregon:eek:

OBDI port btw. What directions are you using for it? There are specific sequences to operate it.

The instructions here are pretty good; try it again.

If all else fails, take it to AutoZone or somewhere & ask them to clear it. You may also want to get a defferent code reader.