1994 F250 a/c problems
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1994 F250 a/c problems
I have searched the forums and not found anything similar to my problem so I figured I would get some input. I have 1994 F250 5.8 E4OD that I have had for a few years. Finally decided to get the A/C hooked up and working. It had a leak that I fixed. The problem is when I turn on the A/C or defrost the engine shuts down. This only happens when the truck is first started. I can let it warm up or drive it for 5 to 10 mins then the engage the a/c and it works as normal. I have replaced the IAC valve already. It's like you just shut the key off. I have checked codes with my Snap-on scanner and have no KOEO codes. KOER I get a code 172 which is a O2 sensor code and that's because it doesn't have one anymore. J have checked codes in the past and get a 512 which is KAM memory but it doesn't always come back. Just curious if anyone thinks it could be the PCM causing my problems?
Fleet Owner
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From: Kentucky
At the very least you should get the System Pass Code of 111 for KOEO and the same if there are no stored codes.
Your truck needs an O2 sensor to run properly, eliminating it can and most likely will cause very strange symptoms.
Code 512 indicates a problem with the computer's memory. A sign the PCM may be bad or going bad. It can also be triggered if you remove a battery cable to clear the stored codes.
Your truck needs an O2 sensor to run properly, eliminating it can and most likely will cause very strange symptoms.
Code 512 indicates a problem with the computer's memory. A sign the PCM may be bad or going bad. It can also be triggered if you remove a battery cable to clear the stored codes.
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Yea I get the code 111 all systems normal. Sorry I should have put that instead of no codes. Yea I understand about the O2 sensor but the truck runs great. Just like you up and shut the key off when you turn the A/C on when you first start the truck. Almost like the PCM loses its memory and needs to run for a few minutes to get back to normal operation.
Fleet Owner
Joined: Oct 2005
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From: Kentucky
If you have not been pulling a battery cable to clear the memory then your Code 512 is pointing towards a memory problem. Could be the computer of the KAM supply itself.
It's time to pull the computer (PCM) inspect the connector/pins and open it up for signs of leaking capacitors.
It's time to pull the computer (PCM) inspect the connector/pins and open it up for signs of leaking capacitors.
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