Code PO 121 any suggestions?

[me4osu]

Thanks. I'll try the cleaning today and post in a few days what the result was.

 

[MYTRNx3]

--- Yes, 2500cummins has butter fingers...

 

[me4osu]

Well, did the cleaning, still had the problem. I performed the checks per my manual and found APPS supply under 5.5V, but IVS#2 to block was 4.67V. Over 4.5V, the manual says to "repair short to voltage". Anyone seen this before?

I haven't called Mass Diesel yet, obviously. I plan to by the end of this week.

 

[MYTRNx3]

I hate to be the one to inform you - but it may be time for a $400 investment in a new one... I guess it takes throwing/dropping the sucker on the ground...

 

[me4osu]

Just talked to Scott. He said it is most likely the APPS. I'm going to try to find someone with a scan tool to double-check before I drop the 4 bills.

 

[MYTRNx3]

Good luck! Bummer it didn't work...

 

[me4osu]

I had my frienly local 5-star dealer check it today. They said that both the APPS and the MAP sensor were failed. I guess the failed MAP was where the excessive voltage was coming from on IVS#2. I have them both on order. The dealer said that I would have to pay two hours labor to do the install. I can install both in 30min myself.

 

[MYTRNx3]

Wow! How much for the parts though?

 

[me4osu]

$409.00 for the APPS.

 

[MYTRNx3]

YIKES --- Need a hug? Damn...

 

[me4osu]

I feel so violated.

However, no 'mo codes.

BTW: A 1-1/4" deep-well socket is the only thing that will remove and install the MAP. Had to make a quick run to NAPA, in the wife's rig, to get one.

 

[MYTRNx3]

Yea, I'm expecting that in my future... and a clutch...

 

[holtzer1]

i had the same code on mine....turns out that the reset procedure you guys are using is a temporary fix...apps sensor is dropping out...get a new one or find yourself roadside at idle befor too long.

 

[MYTRNx3]

Actually -- I should have updated this particular thread --- If you take the APPS off and bang it on the bumper a few times --- OR accidently throw it up in the air, letting it hit the ground --- for some strange and odd reason fixed the problem with mine... at least it isn't throwing codes anymore... Still having some other undiagnosed issues with fuel however...

Try the "banging" techquine first.