Power Control Module
 

Hi,

I have a '96 Accord LX 2.2 L. It has a TON of miles on it (odo stopped working at 141K about 7 years ago).

Anyhoo... Recently, when I went to start it, it would start, then very quickly die (rune about 2 seconds), I would then start it, and everything would be fine. Finally, it decided to not run altogether. I had to have it towed home.

Here is a list of the checks I've made thus far:

1. Checked fuel filter/ replaced.
2. There was gas all the way up to the fuel rail. (have NOT checked injectors yet)
3. Checked to see if fuel pump mad a humming noise when key is in 'on' position (it did NOT make any noise)
4. Checked for voltage at connector for fuel pump (none was present)
5. Wiring up to fuel pump is OK.
6. Hooked up hand-held scanner to power control module. It was un-able to communicate with the computer. I attempted several times with the same results. I also checked it on my wife's car, and it was able to communicate with that computer.

Is there any other checks I missed/should be doing? Other than the injectors?

Is there a way to verify if the car's computer is indeed bad, before paying $600.00 for a new one?

Thanks for your help.

3) When you turn the key ON, the pump is supposed to run ONLY for 2 seconds then stop. You need to listen during those first 2 seconds.

4) ... same as 3...

6) What kind of scanner? OBD-2 includes at least 3 or 4 different data protocols & not all scanners read all types of car. I had a cheap little $40 one from Harbor Freight that read my 2001 Saab but would NOT read any of the Hondas I owned.

Thanx for the reply. :)

Upon further investigation, I DID hear the pump run for the 2 second bit.

The scanner in question is an actron OBD II (model CP9175). It DID read and clear the codes (I had to replace a cat. converter) in the past. So, I'm pretty sure it would be working this time, too. After all, it read the codes on my wife's Hyundai Elantra.

I also checked out the injectors. They were within the spec for resistance.

I've also been doing some research, and came up with a fuel pressure as a pretty common cause. When I attempted to start the car, I only heard 2 clicks, you're supposed to hear three. According to this webpage:
http://www.tegger.com/hondafaq/mainrelay.html

hmmm... I thought there's only 2 clicks, but I never owned a 1996.

The computer is responsible for triggering the main relay to switch the pump on & off, so I guess in some way the computer is not scrap.

I think 1996 still has the SCS connector (in addition to the OBD-2 plug). You can jumper that with a paperclip (just like checking CEL codes in a OBD-1 car). Then the CEL should stay on solid if there's no errors.

I am not familiar with the SCS connector. What is it? Where is it located?


I appreciate your help thus far.:cool:

either behind the ashtray or behind the passenger kick-panel.

The SCS connector is the 2-wire connector that you jumper with a paperclip, to read CEL codes in an OBD-1 Honda. The CEL will flash - long=10, short=1. I'll go look for a post with actual instructions.

Here's a link, courtesy of DesertHonda...
http://www.troublecodes.net/honda/
Scroll down to your year, it says the SCS connector is below the dash? It's a blue plastic plug, 2 wires, & normally is held inside a rubber socket thing, not really CONNECTED to anything.

Scroll all the way down to get the lists of codes. The "MIL" column is the flashing-CEL version of reading the codes.

Thanx for the help, Jim.
I tried to get the fuel pressure relay to click, and it didn't. I also couldn't get a reading off the cars computer, either. I'll have to try the SCS connector, and get back to you.

Well, I found the connector, jumped it with a paper clip, and waited for the CEL to flash. Nothing. No flash, just a solid CEL light. I even repeated the test several time, and got the same result.

I am at a complete loss, here.

Solid CEL is supposed to mean the ECU is OK and has passed its own internal self-diagnostic.

You said the fuel pump relay doesn't click, but you said earlier that you DO hear the fuel pump running?

Maybe it's time to take NOTHING for granted, & check whether you have spark? Got a timing light? (I probably should have suggested that right at the beginning...)

After TRYING to start, you can pull a spark plug to see whether there's any fuel-smell in the cylinder.

A sloid CEL means all is OK. That's a relief. A ECU costs about $600!

Checking for spark and gas was one of the first things I did.
It does have spark on all cylinders. I pulled one of the plugs, and it appeared to be dry.

I do have a timing light.

Before I pulled the relay to check it, it was clicking. After testing, it wasn't clicking, or energizing the fuel pump for the first few seconds after the key was turned to on/start.