Completely stock 00 civic dx. OBD2 will not pull data. CEL works when jumping using paper clip method. Pins 12 and 13 (grounds) have continuity. Port has power. Pin 15 and A21 on the ECU have continuity. All fuses are good. Tried resetting ECU. I’m stumped. Any ideas?

 

Not to state the obvious, but have you tried a different scanner? And have you tried w the engine running/w just koeo?

 

Yes, tried multiple scanners, even taken to Advance and AutoZone to let them try. Tried with Ignition on, car running and completely off. Same result every time. Sorry I should’ve elaborated on that more.

The only thing in the car I have swapped out is the cluster to have a tachometer.

 

With the ignition in the ON position, there should be pulses on the K-Line, PCM pin A21.

 

Going to try this in a few. Question, if it ends up being the ECU, if I buy the same one do I need it reprogrammed?

 

2000 Civic looks like it didn't have the Immobilizer system; so, no programming necessary.

 

You may want to also check/re-check:

Battery power at the Wht/Red wire terminal no. 8.
Continuity to ground at Blk wire terminals no. 12 and no. 13.

Check for the correct wire colors and terminals.

 

All of this is verified.

Although, the A21 pin is receiving a steady 0.21 no pulses.

 

If there is no pulse from the K-line, then it probably is due to the PCM. You can open the PCM to see if there is any obvious damage, such as blown/leaking capacitors and/or burnt resistors. PCM may still be faulty even if you don't see anything that looks bad.

 

Thanks, will be seeing if I can score one at the salvage yard tomorrow. If not I’ll order one. Will update after.