Two questiosns- DDEC V

1. This morning it wouldn't start & gave a code of ICU 140. It finally started, has started fine since & isn't showing the code. Anybody know what that code means?

2. My tach reads 200 RPM low. My dealer of choice says there's nothing they can do to calibtrate it. They claim that if it is in fact inaccurate I will need a new guage cluster. They want to hook up a laptop & drive it around the block to see if the signal from the ecm matches what the tach is showing. I told them I thought that was moronic, there's no need to drive it, you should be able to see it sitting at idle (or any other rpm). Does anyone know if there is a way to calibrate the tach via the ecm?

Thanks in advance.

 

I believe it is low throughout the entire rpm range. It idles @ about 350 rpm & comes on the governor around 1800 on the tach.

At first I thought the dealer that sold me the truck was wrong about the rear end ratio. To be at 60 @ 1400 RPM I was running in 17th gear, which is not right for 3.70's. I got my dealer to print the specs out which showed 3.70's, jacked the back axle up & verified that I do indeed have 3.70's. I started running 60 at 1200 rpm indicated in 18th & seem to have picked up a couple of tenths.

I'm contemplating trying one of Kevin Rutherford's Scan Guages even though I can't stand his personality or political philosophies and believe that he is basically a charlatan.