PCM READNESS CODES

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Oct 17, 2022 | 07:09 PM

terry br

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PCM READNESS CODES

I have a 1997 f350 7.5 the readiness monitors codes reset when truck is turned off. It will not smog

Oct 18, 2022 | 01:03 AM

Prototypemech

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From: Mojave, Ca

Check your 'i' fuse in the engine compartment fuse box and check the terminals for corrosion or melting. It's probably fine because the 'i' fuse also supplies power to the ECM, so if I was blown, your truck wouldn't start, but it may have enough corrosion to drop the battery voltage down enough to loose keep-alive memory.
Next this is to remove the ECM connector from the ECM. It's below the master cylinder and has a 10mm bolt holding it in.
Use a multimeter to check pin 1 voltage. It should be 12v. If it is 12v, your ECM is dying and needs to be repaired/replaced. If it's not 12v, you need to trace the pin 1 wire and find out where it's broken/bad. First place I would check would be in the engine compartment fuse box where the wire connects to the 'i' fuse.

Oct 18, 2022 | 09:06 PM

terry br

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Thank you this is a california truck mass air keep alive is 55 thanks for heads up,it is to dark to see now again thank you

Oct 19, 2022 | 06:23 AM

rla2005

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From: Kentucky

I believe the fuse naming scheme changed around 1996. It is Fuse 9.

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Oct 19, 2022 | 11:18 AM

terry br

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thank you fuse are good 12.64 volts @ pin 55 I guess new computer

Oct 19, 2022 | 11:37 AM

Prototypemech

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From: Mojave, Ca

Yup. I suspect you need a new ECU.

Oct 19, 2022 | 12:05 PM

rla2005

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From: Kentucky

Seems like an odd failure mode. I would also expect a code for the Keep Alive Memory failure, P0603, but if the computer is bad that may not happen. X2 on a vote for a new computer (PCM).