[hgani]

Today I discovered one reason why the check engine light comes on along with messed up transmission, "P" and "D4" light up at the same time and the transmission clunks continously.

A little background:
I've had Crimestopper remote starter installed on my '99 Odyssey EX for 2 years now, always works like a charms never gives me any trouble. But, I never connected the Anti-Grind feature to prevent grinding the starter because I didn't want to cut the starter wire.

Well lately, I've been careless and grind the starter a few times. I finally decided to use the Anti-Grind feature which is normally done by using 3-wire relay with a diode across the coil. I've installed this stuff on cars a few times without any problems, not a big deal...so I thought.

Once everything hooked up, I tested it by turning the key to start while the engine is running, works like a charm. But when, I shifted the transmission from "P" to "D4", that's when things run havoc on me.
The transmission started to make clunking noises and both "P" and "D4" light up at the same time, I quickly turn the engine off. Check all my connections, found no problem, so I tried again and this time the Check engine light stays up in addition to the problem with the transmission. I thought, "boy, I screwed up". I traced the problem to the relay that I just installed, time to get the Service Manual out. I reset the PCM by pulling the "Clock Backup" fuse at the passenger side fuse panel for 10 seconds. After a couple of hours poking wires and testing, I was finally able to install the relay but I couldn't use the Starter wire to energize the coil, that's what screwed upt the PCM.

So, if anyone ever experience the "P" and "D4" light up at the same time and the transmission starts jerking, remember that it is NOT the transmission problem, it is the PCM computer that experience a mulfunction.

Sorry for the long post.

------------------
Harry
'99 Odyssey Pictures

 

[ceng]

Hi Harry,

I do not have the transmission clunking problem, but when I turn the key to on, the P and D4 lights up at the same time, give it two seconds, then the D4 light goes away. Is this normal? Can you also tell me the page number on Helm's manual relate to resetting the PCM?

I tried your trick but pulling the "Clock, backup" fuse for more than 10 seconds but the problem still exist.

 

[hgani]

Resetting the PCM only resets the codes that have been generated, it doesn't fix the problem.
In my case, the problem was caused because my remote starter still supplying negative to the starter kill relay when I start the car when it shouldn't, causing havoc to the PCM. I simply connect the relay to another negative output of the remote starter and reset the codes.

Your case however, is something else because you don't know the cause of the problem. If you can reproduce the problem, take to the Dealer, they can check the errors stored in the PCM. Don't let the Dealer tells you that it's normal or it's okay because it is NOT!
Ask them to show you a new Odyssey that does the same thing, else, tell them you want it fixed.

Good Luck.

-Harry