code 54

[Gerry]

i have code 18, 35, 54. truck starts with difficulty.

 

[Will L.]

Welcome. More info can be helpful- fill out the signature line with truck and any modification details, then it always pops up so we can see what we are dealing with.

Do not just throw parts at it- that makes it worse because so many new parts come defective now days. And with that- ask before buying because many of us learned where to avoid rip off places. Brick and mortar AC Delco AUTHORIZED dealer is good, LeroyDiesel.com is good online- there are others

That 54 according to manual when not paired with code 17 says to replace the pcm- but do not do it until other options are 100% knocked out because changing it by itself rarely fixes it.

Start with the pain in the neck of remove, clean, reinstall all engine and battery grounds. This is a HUGE common problem and solves this issue maybe 25% of the time.

If you still have the optic sensor filter- remove it and plug the two ends of harness together bypassing it.

Next is I am guessing you don’t have a spare pmd (because you didn’t mention trying it).
Unfortunately there is no way to test pmd but they fail often enough and only test from GM is “replace with known good”. We learned to mount them on the back side of front bumper using a heat sink and an extension cable.
Leroy sells a good extension cable and lifetime warranty pmd. The trick is use the new lifetime warranty one and keep an old working unit like spare tire. Years later when lifetime one dies, drive on the old one while mailing off warranty unit for replacement. Pmd fails in crazy ways and can cause almost any problem. It is the thing that gives this engine a bad name.

Start with that info and anything more you can tell us will help solve your issue faster

 

[Gerry]

My PmD has been relocated. Thank you I will try your recommendations

 

[Will L.]

I see you started two threads. It will be better to keep it all together so everyone can follow all questions.
For other readers here is the other thread that has more responses on it:

code 54

while driving engine stopped. started again with difficulty. i have codes 18, 35 and 54. need help diagnosing

www.thetruckstop.us

 

[jrsavoie]

Welcome. More info can be helpful- fill out the signature line with truck and any modification details, then it always pops up so we can see what we are dealing with.

Do not just throw parts at it- that makes it worse because so many new parts come defective now days. And with that- ask before buying because many of us learned where to avoid rip off places. Brick and mortar AC Delco AUTHORIZED dealer is good, LeroyDiesel.com is good online- there are others

That 54 according to manual when not paired with code 17 says to replace the pcm- but do not do it until other options are 100% knocked out because changing it by itself rarely fixes it.

Start with the pain in the neck of remove, clean, reinstall all engine and battery grounds. This is a HUGE common problem and solves this issue maybe 25% of the time.

If you still have the optic sensor filter- remove it and plug the two ends of harness together bypassing it.

Next is I am guessing you don’t have a spare pmd (because you didn’t mention trying it).
Unfortunately there is no way to test pmd but they fail often enough and only test from GM is “replace with known good”. We learned to mount them on the back side of front bumper using a heat sink and an extension cable.
Leroy sells a good extension cable and lifetime warranty pmd. The trick is use the new lifetime warranty one and keep an old working unit like spare tire. Years later when lifetime one dies, drive on the old one while mailing off warranty unit for replacement. Pmd fails in crazy ways and can cause almost any problem. It is the thing that gives this engine a bad name.

Start with that info and anything more you can tell us will help solve your issue faster

I thought the PMD could be tested for power going back to the Injection Pump?