91 F150 codes
Thread Starter
|
Mountain Pass
Joined: Jun 2009
Posts: 248
Likes: 0
From: East Wenatchee, WA
91 F150 codes
This is a re-post not getting any help, so I changed the title and added some info.
91 F150 in my sig, PCM is out of a 95 F150
I cleared the codes and drove it around, its still not running that great, surging at light throttle, have to rev it more than usual and drag the clutch to get it to go and not die form a stop.
I replaced the MAF sensor and the distributor, with a MSD bronze gear on it, because the last gear got chewed up.
Read the codes again and got these this time:
511 - read only memory test failure - no idea what this is
638 - trans oil temp - doesnt matter I have a 5 speed
565 - canister purge solenoid circuit failure
652 - trans over temp - ignore also
10
158 - MAF sensor fault over voltage
638 - trans oil temp - doesnt matter I have a 5 speed
The only ones that Im worried about are in bold. Im pretty sure that the canister purge solenoid isnt on my truck any more. Looks like this right?
If thats it then its def gone, hasnt bee hooked up since Ive owned the pickup.
I just replaced the MAF, so why is it still throwing a code?
Can someone please tell me what the Read Only Memory code is all about?
91 F150 in my sig, PCM is out of a 95 F150
I cleared the codes and drove it around, its still not running that great, surging at light throttle, have to rev it more than usual and drag the clutch to get it to go and not die form a stop.
I replaced the MAF sensor and the distributor, with a MSD bronze gear on it, because the last gear got chewed up.
Read the codes again and got these this time:
511 - read only memory test failure - no idea what this is
638 - trans oil temp - doesnt matter I have a 5 speed
565 - canister purge solenoid circuit failure
652 - trans over temp - ignore also
10
158 - MAF sensor fault over voltage
638 - trans oil temp - doesnt matter I have a 5 speed
The only ones that Im worried about are in bold. Im pretty sure that the canister purge solenoid isnt on my truck any more. Looks like this right?
If thats it then its def gone, hasnt bee hooked up since Ive owned the pickup.
I just replaced the MAF, so why is it still throwing a code?
Can someone please tell me what the Read Only Memory code is all about?
Fleet Owner
Joined: Oct 2005
Posts: 20,789
Likes: 1,753
From: Kentucky
Sounds like you are pegging your MAF. You are going to need a different MAF or a tuner that can modify the MAF return signal somehow.
I would assume you used a PCM from an auto transmission equipped donor vehicle.
DTC 511 is not a good thing, indicates the ROM memory test failed. Could indicate the PCM is bad.
I have seen a different style canister purge valve assembly on the later model trucks. The one you show looks just like the one on my '92 F-350. There may be a different impedance between the two causing a false DTC code?
I would assume you used a PCM from an auto transmission equipped donor vehicle.
DTC 511 is not a good thing, indicates the ROM memory test failed. Could indicate the PCM is bad.
I have seen a different style canister purge valve assembly on the later model trucks. The one you show looks just like the one on my '92 F-350. There may be a different impedance between the two causing a false DTC code?
Thread Starter
|
Mountain Pass
Joined: Jun 2009
Posts: 248
Likes: 0
From: East Wenatchee, WA
Sounds like you are pegging your MAF. You are going to need a different MAF or a tuner that can modify the MAF return signal somehow.
I would assume you used a PCM from an auto transmission equipped donor vehicle.
DTC 511 is not a good thing, indicates the ROM memory test failed. Could indicate the PCM is bad.
I have seen a different style canister purge valve assembly on the later model trucks. The one you show looks just like the one on my '92 F-350. There may be a different impedance between the two causing a false DTC code?
I would assume you used a PCM from an auto transmission equipped donor vehicle.
DTC 511 is not a good thing, indicates the ROM memory test failed. Could indicate the PCM is bad.
I have seen a different style canister purge valve assembly on the later model trucks. The one you show looks just like the one on my '92 F-350. There may be a different impedance between the two causing a false DTC code?
I sent off the PCM and had them put a chip in it to run my engine, so maybe when I go back to fine tune it once I can finish the 500 mile break-in they can fix it.
The PCM is from a E40D pickup.
Anyone else want to chime in on the ROM issue? I dont like his answer
.Is the CANP code going to cause my pickup to run differently or just throw a code? Not gonna worry about it if its just a code.
Fleet Owner
Joined: Aug 2005
Posts: 23,667
Likes: 301
From: Easton,Ks
The 511 means you have to replace the PCM Computer.
Thread Starter
|
Mountain Pass
Joined: Jun 2009
Posts: 248
Likes: 0
From: East Wenatchee, WA
So is the purge valve code gonna mess up the running of the engine or just make a check engine light?
The MAF getting pegged seems a bit unlikely, because it was running better, not tip top, but better before. I got a PIP code and replaced the distributor because of the chewed up gear, plus replacing the MAF. Seems like it would be something else causing the surging and such.
Could the 511 ROM code be causing the pickup to be running rough?
The MAF getting pegged seems a bit unlikely, because it was running better, not tip top, but better before. I got a PIP code and replaced the distributor because of the chewed up gear, plus replacing the MAF. Seems like it would be something else causing the surging and such.
Could the 511 ROM code be causing the pickup to be running rough?
Fleet Owner
Joined: Oct 2005
Posts: 20,789
Likes: 1,753
From: Kentucky
I doubt the purge valve is going to cause any damage, it's more of a nuisance issue. The MAF code is reported by the PCM. Whether or not it is a true reading is subject to verification. Regardless if the MAF feedback signal is really above 4.5V the main issue here is the PCM THINKS it is going above 4.5V. Add in the 511 ROM code you may be correct, the MAF is not truly going above 4.5V but the PCM is screwed up.
It's your choice to act on the 511 code. Two of us have given feedback that code 511 is not good and the most likely resolution is to replace the PCM. You were given free advice, do with it what you want.
It's your choice to act on the 511 code. Two of us have given feedback that code 511 is not good and the most likely resolution is to replace the PCM. You were given free advice, do with it what you want.
Trending Topics
Thread Starter
|
Mountain Pass
Joined: Jun 2009
Posts: 248
Likes: 0
From: East Wenatchee, WA
I really appreciate the input, the reason Im asking is that I cant just throw in a stock PCM in and have it run right, which makes it that much more of a pain in the butt. I need to take the truck over and have it tuned on a dyno to make it run 100% and I was hoping to be able to drive it over to the shop which is 3 hrs away, and then put the new PCM in and have them tune it up.
An rla2005 when I said I didnt like your answer about the ROM I was just trying to be funny, sorry if you took it differently
An rla2005 when I said I didnt like your answer about the ROM I was just trying to be funny, sorry if you took it differently
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
3 Best / 3 Worst Parts of Modern Ford Ownership
Brett Foote
10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches
Pouria Savadkouei
Every 2026 Ford Engine Explained
Brett Foote
10 Ugly Ford Trucks That We Still Kinda Love
Joe Kucinski
10 Things Every Truck Owner NEEDS (2026 Edition)
Michael S. Palmer
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath
Verdad Gallardo
Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer
Joe Kucinski
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)
Brett Foote
Top 10 Ford Truck Tragedies
Joe Kucinski
Thread
Thread Starter
Forum
Replies
Last Post
07EXPYEL
2007 - 2014 Expedition & Navigator
6
Oct 11, 2016 11:40 AM
'90-f150-302-5spd
1987 - 1996 F150 & Larger F-Series Trucks
24
Jun 1, 2016 12:51 PM
crosaire
1987 - 1996 F150 & Larger F-Series Trucks
10
Mar 8, 2016 05:17 PM
