CEL Question

Ira R.

Ira R.

Registered User
I'm wondering if anyone else has come across this problem. I am getting a very intermittant CEL. I mean very. Never stays on for more then a miute or two and then it goes away for a while. No rhyme nor reason, no pattern to it that I can see.

Ran the codes and got
341 - Octane Adjust Service Pin in Use

Cleared the codes and got the same next time out.

So now what the hack is that?? When I try and trouble shoot it my info points me to the Octane Adjust Shorting Bar. As far as I can tell everything looks right where it is supposed to be.

Has anyone else ever gotten this one?

Ira
 
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Well, we cleared the all the codes and it's back. Not so much local driving but at high speed she flashes on and off pretty much all the time.

The only common thread I see is that all of the error codes include a line item that says, "replace PCM".

Is there a way to test it? So how big a problem is that?? Do all those little wires need to be reconnected one at a time to the new plug??

Ira
 
341 - Octane Adjust Service Pin in Use
Click to expand...

This refers to the "octane plug". It pulls some timing to reduce the chance of detonation when running low grade fuel (the assumption is that Ford put it there for emergencies when premium fuel isn't avail.). Search for octane plug for more info... the plug may be missing, the contacts might be dirty or a wire might be broken.

all of the error codes include a line item that says, "replace PCM".
Click to expand...

What other codes are you getting?

My 94 does the flashing CEL/MIL light thing every once in a while when cruising. I've traced it to an EGR problem. Now I have an excuse to get rid of the EGR altogether :)

Vince

p.s. No you don't need to move the wires over one by one! The wires terminate on a plug so the change over is pretty easy.
 
Vince_Hayduk said:
This refers to the "octane plug". It pulls some timing to reduce the chance of detonation when running low grade fuel (the assumption is that Ford put it there for emergencies when premium fuel isn't avail.). Search for octane plug for more info... the plug may be missing, the contacts might be dirty or a wire might be broken.


What other codes are you getting?

My 94 does the flashing CEL/MIL light thing every once in a while when cruising. I've traced it to an EGR problem. Now I have an excuse to get rid of the EGR altogether :)

Vince

p.s. No you don't need to move the wires over one by one! The wires terminate on a plug so the change over is pretty easy.
Click to expand...

Then maybe I should just swap in a new PCM and see if that fixes this. As far as the octane plug, I thought maybe I got a bad tank of gas, but I have cycled through 3 tanks now, using 3 different brands of 93 octane.

The other codes that come up are :

171 - No EGO Switch
172 - EGO Not Switching, Lean bank one
528 - Clutch Pedal Switch
556 - Fuel Pump Relay

Now the O2 sensors have been checked and were just replaced. The car starts, so how bad could the clutch pedal position switch be, and if the fuel pump relay was bad wouldn't the pump shut down??

This is just very confusing.

Ira
 
The more I think about it I have a suspicion that there may be a problem with the right bank 02 sensor still. It might not even be the sensor. If the EEC thinks that it is lean on that side it would explain why it keeps dumping fuel and giving you such poor mileage. When I tuned the car that 02 sensor was disconnected. I also noticed that the 02 sensor we bought for the car was not a Bosch unit. It really could be that the sensor is bad.
 
XR7 Dave said:
The more I think about it I have a suspicion that there may be a problem with the right bank 02 sensor still. It might not even be the sensor. If the EEC thinks that it is lean on that side it would explain why it keeps dumping fuel and giving you such poor mileage. When I tuned the car that 02 sensor was disconnected. I also noticed that the 02 sensor we bought for the car was not a Bosch unit. It really could be that the sensor is bad.
Click to expand...

Replacing the sensor is easy enough. In fact I should replace both just to be sure. I'll see if that does anything.

I will hold off on the EEC until afterwards.

Ira
 
Ira R. said:
Replacing the sensor is easy enough. In fact I should replace both just to be sure. I'll see if that does anything.

I will hold off on the EEC until afterwards.

Ira
Click to expand...

Ira:

I replaced my O2 sensors with Motorcraft ones from Rock Auto, they were the cheapest for OEM if you wanna stick to that, plus they are pencil thin compared to "magic marker" thick if clearance is an issue.
 
pablon2 said:
Ira:

I replaced my O2 sensors with Motorcraft ones from Rock Auto, they were the cheapest for OEM if you wanna stick to that, plus they are pencil thin compared to "magic marker" thick if clearance is an issue.
Click to expand...

Thanks for the suggestion Paul, but right now cheap isn't the issue. I just need to get all of this miscellanious crap resolved once and for all and get the car back on the road.

Ira
 
As far as the octane plug, I thought maybe I got a bad tank of gas, but I have cycled through 3 tanks now, using 3 different brands of 93 octane.
Click to expand...

The octane plug is a physical "jumper" plug. Do a search and you'll come up with lots of info (including it's location). If you are still getting a code 341, make sure the plug isn't missing. If it's there, unplug it, clean the contacts and then plug it in again.

528 can also be a/c on during the test...

I'm not sure about the fuel pump code... I'm with you that it shouldn't be running if the relay was bad.

Vince
 
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