Even in the Helm book, the grounds are scattered around in a lot of different wiring drawings.

 

Yeah. Im gonna have to go through all the diagrams I guess. Although that thread that I found on the 1297 on a 97 prelude said that there was a ground missing from the thermostat housing, I didnt see anything near there. Then again it was most likely an H22...
Even with a wiring diagram I wouldnt be able to know what theyre grounded to unless I follow the wire. And that can get tricky.

 

Ok. So an update. I had reset it and cleaned some connections. 60 miles later, right after flooring it (just cuz I gotta do it once in a while on those perfect roads) the CEL came on. I'm assuming its the same thing. Now I'm thinking theres a vacuum leak thats only opening up when theres a lot of air being drawn in, but something interesting happened. After that, the idle did what its been doing- staying at 1000rpm for a second, but this time it was a little longer, and then I saw the dashboard lights dim real quick and then the idle went down to normal at 750. That suggest anything? Definitely sound like the ELD?

I did get a download of the factory service manual. Its pretty big. 1000 something pages. But its useful. I actually found diagrams of the ground locations and the harnesses.

If anyone wants or needs a FSM for the 4cyl 97 Accord I can send it.

But heres the thing thats bothering me- I cant find any info on 5th Gen accord ELDs. theyre on other hondas. But looking through this FSM and online, theres no info.

 

The ELD is built into the under-hood fuse/relay box, see attached pic.

For P1297, check the ECU ground at G101, see attached pic.

P170 and P171 may be due to the primary O2 sensor.

 

Thanks for your post. this gives me a lot of hope actually. Now the FSM had nothing on the ELD. It showed the fuse box and did not label (even though its built in) so I was at a loss. But I did see the g101 connection in the diagrams. that one I had to take off and put back on during my intake manifold swap. What I did was use a wire brush on the part where I connected the ground on the manifold. I dont see why it wouldnt ground on the f23 manifold. Should I try just attaching it to the chasis or does it have to be on the manifold? a ground is a ground right?

As for the other two codes. They come on exactly when the light comes on. So its all three codes at the same time. Would that indicate that theyre related?
But I'm suspecting the o2 sensor as well although I dont get an o2 sensor code. maybe its not faulty enough to have the actual sensor code? What I found a while ago was oil in between the o2 sensor and harness connection. I cleaned it and reattached it. It was an inexpensive but good quality o2 sensor i replaced a year ago. The o2 sensor voltage readings would be a bit low at times.

Whats my best approach here after checking the grounds? Replace o2 sensor? Replace fuse box? As to not throw away money but have a good bet on what will fix these issues. I'm gonna test the grounds voltage but how do I know if I have a bad o2 sensor without an actual o2 sensor code.

 

I just checked some stuff on my car. I check g101. it was secure but also, the car does not run without it. So if it wasnt secure my car would randomly shut off. I did the test to see if its the ELD. According to the instructions because theres no CEL when I turn on the headlights then I gotta check for loose connections.
There was an issue I saw that I've fixed before but it came back- the o2 sensor connection has oil in it. its from oil dripping down the harness behind the engine. I cleaned that out real good, wrapped part of the connection with electrical tape and propped it up above the harness.
So could oil in the connection cause all 3 codes? I know it could cause the 0170 and 0171. But what about a low ELD voltage?
This is just a guess but a lean engine restricts the amount of work the alternator does to supply power to the devices when active thus causing confusion with the ELD?

 

I don't see why either. I just hooked G101 to the F23's intake manifold too with no problems. Grounds aren't all equal. Sensors are low voltage, take very little current, and good grounding is essential to having them work correctly. Intermittent dimming dashboard lights could definitely be caused by a bad ground. Break out a DVM and check continuity between the negative battery post and the engine ground lugs. There shouldn't be more than a couple ohms resistance.

 

Ok. So switch my ammeter to ohms and measure the grounds like g101 and the negative battery terminal?

Its rather random but I cant tell if I have a vacuum leak or the idle is related to the issue and its all electrical. Perhaps the ground wire for the IAC?

 

So I think the RPM could or could not be related but I cannot find any vacuum leaks. But the cars electrical is sometimes affected when the idle goes back to normal. I notice the RPMs go up when I push on the brakes too.