How Do I Repair Error Codes

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How Do I Repair Error Codes

July 07, 2006, 02:55:37 PM

I have an intermittent check engine light coming on. It did not do this until I removed the airbox and and replaced it with a K&N cone.
The codes I have pulled are -
51-ECT sensor signal too high
53-TPS circuit above 4.5 volts
54-ACT sensor signal too high
I also pull a #34 - PFE or EVP curcuit above the closed limit of .67 volts. I have pulled this particular code for a while and can't find any reason.

That being said, how dod I go about correcting these? Would resetting the ECM be a step in the right direction?

How Do I Repair Error Codes

Reply #1 – July 07, 2006, 08:50:30 PM

Somebody correct me if I'm wrong.

You can reset the computer by unplugging the battery. Just unhook it and leave it for 10 minutes or so.
While this will clear the codes, they will most likely return and bring the CEL back with 'em.
I've also read that it's possible for codes to be stored without the CEL being illuminated. I find it interesting that swapping the air filter makes a code come up for the TPS.
You may consider resetting the computer, then driving the car for a while and scanning it again.

How Do I Repair Error Codes

Reply #2 – July 08, 2006, 12:39:24 PM

I removed my test wire while I pulled codes then I disconnected the battery. Figured that should clear the codes and the memory. Reconnected the battery and went for a drive. Ran like a top. No check engine light. Went all speeds - even got it up to 95 before common sense took over.
Got back to the house and pulled codes. All previous codes were gone EXCEPT the same #34 is coming up both KOEO and KOER. No vac problems, EGR tests good, etc.
I didn't realize just how much difference changing to a CAI would effect the ECM. I guess it needed some help finding its bearings with a reset.
I have heard of #34 coming up a lot for many different reasons - anything else I could look for?

How Do I Repair Error Codes

Reply #3 – July 10, 2006, 03:19:49 PM

I don't know anything about your car or engine. On the Turbo Coupes a code 34 is EGR not working code.

How Do I Repair Error Codes

Reply #4 – July 10, 2006, 07:07:42 PM

Quote from: turbopete

I don't know anything about your car or engine. On the Turbo Coupes a code 34 is EGR not working code.

I have an 88 Cougar with the 5.0 - PFE or EVP circuit above the closed limit of .67 volts

How Do I Repair Error Codes

Reply #5 – July 11, 2006, 09:50:33 AM

Ford
Engine/Emissions-Diagnosis
1988 Shop Manual
(comes in handy at times)

Code 34, 5.0 SEFI
DN20 - Engine off
DN50 - Engine running
.

How Do I Repair Error Codes

Reply #6 – July 11, 2006, 10:15:57 AM

The first thing I did was to replace the EVP sensor. That was a waste of money as the code reappeared. I have checked the EGR to insure that it holds vacuum and doesn't leak down and that the motor stumbles with vacuum introduced.

How Do I Repair Error Codes

Reply #7 – July 11, 2006, 10:40:53 AM

Quote from: cougarcragar

Somebody correct me if I'm wrong.

You can reset the computer by unplugging the battery. Just unhook it and leave it for 10 minutes or so.
While this will clear the codes, they will most likely return and bring the CEL back with 'em.

there are two groups of codes,, if you perform the complete test.

First group of codes will be the codes that are present now

the second group will be the continuous memory codes which have been present for a while. Its like "whats happening now" and "whats been happening in the past. some of the "now" codes will match the "past codes".

Disconnecting the battery does not really clear them. As mentioned, the only way to clear a code is to disconnect your test jumper ***during***** the time in which actual codes are being displayed for the "whats happening now" section.

It may take as long as 40 restarts / warm up cycles for a conintuous memory code to be removed.

I would suggest removing the egr and inspecting / cleaning both the egr and the engine ports. The emissions system can be very tricky. I would also trace out the green vac line and follow it around to the other end. I would put vac on it as well to see if there is a minor leak.

How Do I Repair Error Codes

Reply #8 – July 11, 2006, 11:06:45 AM

Quote from: jcassity

I would suggest removing the egr and inspecting / cleaning both the egr and the engine ports. The emissions system can be very tricky. I would also trace out the green vac line and follow it around to the other end. I would put vac on it as well to see if there is a minor leak.

I'll give that a shot.
Which is the green line?

How Do I Repair Error Codes

Reply #9 – July 12, 2006, 12:33:08 AM

the green vac tube that is connected to the egr. Its what pulls vac on the egr diaphram and that in turn actuates the EVP sensor buy moving the 1/8'' narrow rod you saw on the evp you swapped in.

How Do I Repair Error Codes

Reply #10 – July 12, 2006, 06:28:47 AM

That line happens to be gray on mine. That is where I found a leak when I first got the car. The plastic tube was cracked and I repaired it. Thought that was the end of my problems but that #34 (KOEO, KOER, current, and memeory) just won't go away.

How Do I Repair Error Codes

Reply #11 – July 12, 2006, 08:41:33 AM

Quote

I have checked the EGR to insure that it holds vacuum and doesn't leak down and that the motor stumbles with vacuum introduced.

That just tells you it opens properly.

Quote

I would suggest removing the egr and inspecting / cleaning both the egr and the engine ports.

Me too.
Code 34 is basically the computer saying "I told the EGR valve to close, but the sensor is telling me it's still open". Either the sensor's rod is sticking (not likely), or the EGR isn't closing all the way due to a build-up of carbon on the pintle/seat or the shaft.

How Do I Repair Error Codes

Reply #12 – July 12, 2006, 04:02:47 PM

Another thing to consider:
There two solenoids that control the EGR. The EGR Control solenoid controls the vacuum to the EGR. The EGR Vent solenoid lets air into the vacuum line to allow the EGR to close.
My dospoogeentation is for the "84 CFI. The air line for my Vent solenoid goes to the CFI air cleaner cover. Where it supposedly gets clean air.

How Do I Repair Error Codes

Reply #13 – July 13, 2006, 09:36:18 AM

We 88's (& earlier?) only get a single solenoid, mounted high on the back side of the passenger strut tower, with the smog pump solenoids below it.
.