My car suddenly has a flashing D4 light and check engine light on. I jumped the code hookup and I think I get:

725, 65 from the CEL
8 flashes from D4

(I can't quite figure if I'm reading the codes right.)

If I shift into R to back out of the garage it shifts a little hard but moves ok. Then to get back into the garage I go to D4 and it's like I'm in molasses, rev but little acceleration. So something is clearly wrong with the transmission. I drove the car 10 minutes prior and it was fine.

Now the kicker - did I cause this by messing with my cruise control switch? Background: my cruise control went out over the weekend. It worked on a 1 hr drive on Saturday, then wouldn't turn on on Sunday. Tonight I was trying to diagnose and got to testing the switch on the dash. I determined that I had no continuity where I should have because one of the bulbs was bad (the one that indicates cuise is ON). I swapped the good bulb and bad bulb and went for a test drive. Car drove fine. The ON bulb worked, the other did not (confirming it was burned out). I came back and put a little jumper wire across the bad bulb (I don't really care if CRUISE is illuminated). I started the car again and D4 is flashing.....facepalm.

Are the cruise going out and transmission potentially related? I'm thinking it's more likely what I tried since D4 happened immediately after... UGH.

I should add, I'm just rolling over 94k miles. (it was a granny car for almost 10 years and had 17k on it when I got it)

 

I'm skeptical the cruise problem and D4 flashes are related.

CEL obd1 flashes are two digit codes. There is no 725. Flashes are read as Long Flash (2-3 secs) =10 and short flashes (1 sec or less) as 1. F-ffff = 14. There is a long pause (2-3 secs) between successive codes or repeat of code/s.

Code 8 for TCM is an electrical fault in shift control solenoid circuit; solenoid, connector, wiring, or TCM could be at fault. Manual described how to troubleshoot starting w/ checking solenoid resistance for short or open.

When multiple codes are presented, it's always good to read the codes, reset ECM/TCM and see what returns.

good luck

 

OK. Pretty sure I have 70, 20, 41, and 65.

Is the PCM the same as the ECM/TCM? I see a way to clear the PCM codes by removing the #13 fuse for 10 seconds, but want to make sure that's the right thing to do.

If so, I'll do that and then investigate the shift control solenoid - although I don't see in my Haynes manual where that troubleshooting is quite yet...

Thanks for your help.

 

Turns out it WAS related to the cruise control work. When I tried that little jumper wire routine, I blew the CC fuse, which also happens to have the ECU on the same circuit.

I had checked the CC fuse earlier in the day yesterday but didn't think to check it again after I was having transmission issues. A call to a mechanic friend sent me down that route again (to check fuses), and I owe him lunch!

Now, off to see if I can fix that dang cruise control...

 

Older Hondas had 2 separate control "boxes".
ECM = engine control module
TCV = transmission control module

Yours has those combined into one box.
PCM = powertrain control module

Yes, that fuse #13 should reset the PCM for 1998 - 2002 Accords.

 

Thanks for the clarification.

I replaced the CC/ECU fuse which remedied all the transmission issues. I cleared the CEL codes and now it's smooth sailing.

I've gotta say, getting my hands dirty and understanding more and more about my car is pretty fun