Lots of Signal too low codes after head swap

RockOcean · Post by **RockOcean** » 28 Aug 2022, 19:16

I just installed a remanufactured head from Odessa Cylinder Heads in Clearwater, FL. I got this head since I had a burnt valve, the car has 240k on it so I thought it was best to go with a complete reman head. The only code I had was the misfire on #3 before replacing the head.

But after installing the new head I am getting ECM-6400 & 6410 Camshaft reset valve - Signal too low codes along with the following:

ECM-4000 Canister purge (CP) valve - Signal too low
ECM-4010 Leakage detection module, ventil - Signal too low
ECM-4024 Leak diagnostic unit, pump - Signal too low
ECM-6800 Turbocharger (TC) control valve - Signal too low

I reset the timing a few different times knowing that it was spot on. I am getting these code even with setting the timing 3 times knowing its spot on. I am using a cam locking tool and have set it spot on in the past. One thing I have noticed is that the engine will idle perfect then all of sudden have a rough idle then go back perfect. If you rev it while the idle is rough it revs rough, but when idling perfectly it revs perfectly. For the most part when driving it drives perfect, but every now and then for a little bit it will run super rough. This leads me to believe that it is something electrical causing it to run rough sometimes but good most of the time. I noticed the engine ground was hanging on by a thread so I thought that's gotta be it! Well after replacing that - it wasn't! The car also has a parasitic draw that will kill a battery in 5 days if left hooked up to the battery. I decided to take the car out for a test run again and it starts just fine but the idle is rough right off the bat, then it will idle perfect then back to rough like an on and off switch. Once warmed up I took it out for a spin and it ran great for about 10 miles with no check engine light. I checked the codes again and when I cleared them the check engine light came on right away and it showed the same codes. Super strange the CEL did not come on during that 10 minute test drive right? Anyone have any suggestions on where I should start to get this sorted out? I have a Vida setup.

Post by **jonesg** » 29 Aug 2022, 01:44

i'd look at the simple things first, the parasitic draw should be easy to trace and might shed light.

Post by **firstv70volvo** » 29 Aug 2022, 09:09

RockOcean wrote: ↑28 Aug 2022, 19:16 I just installed a remanufactured head from Odessa Cylinder Heads in Clearwater, FL. I got this head since I had a burnt valve, the car has 240k on it so I thought it was best to go with a complete reman head. The only code I had was the misfire on #3 before replacing the head.

But after installing the new head I am getting ECM-6400 & 6410 Camshaft reset valve - Signal too low codes along with the following:

ECM-4000 Canister purge (CP) valve - Signal too low
ECM-4010 Leakage detection module, ventil - Signal too low
ECM-4024 Leak diagnostic unit, pump - Signal too low
ECM-6800 Turbocharger (TC) control valve - Signal too low

I reset the timing a few different times knowing that it was spot on. I am getting these code even with setting the timing 3 times knowing its spot on. I am using a cam locking tool and have set it spot on in the past. One thing I have noticed is that the engine will idle perfect then all of sudden have a rough idle then go back perfect. If you rev it while the idle is rough it revs rough, but when idling perfectly it revs perfectly. For the most part when driving it drives perfect, but every now and then for a little bit it will run super rough. This leads me to believe that it is something electrical causing it to run rough sometimes but good most of the time. I noticed the engine ground was hanging on by a thread so I thought that's gotta be it! Well after replacing that - it wasn't! The car also has a parasitic draw that will kill a battery in 5 days if left hooked up to the battery. I decided to take the car out for a test run again and it starts just fine but the idle is rough right off the bat, then it will idle perfect then back to rough like an on and off switch. Once warmed up I took it out for a spin and it ran great for about 10 miles with no check engine light. I checked the codes again and when I cleared them the check engine light came on right away and it showed the same codes. Super strange the CEL did not come on during that 10 minute test drive right? Anyone have any suggestions on where I should start to get this sorted out? I have a Vida setup.

Fuse 5 in the engine compartment is blown, it should be a 10A fuse.

RockOcean · Post by **RockOcean** » 29 Aug 2022, 09:34

Thanks for that video! Looks like CEM fuse #32 is showing a 0.4 draw. Any suggestions on what might be causing that?

RockOcean · Post by **RockOcean** » 29 Aug 2022, 09:39

firstv70volvo wrote: ↑29 Aug 2022, 09:09

Fuse 5 in the engine compartment is blown, it should be a 10A fuse.

Nailed it! Thank you firstv70volvo :~ )

RockOcean · Post by **RockOcean** » 29 Aug 2022, 10:10

Woohoo this forum is the best! After replacing the fuse it still had the rough idle but it now showed a code for a Misfire on #2. Replaced the coil pack now its all good. Thank ya'll so much! Looks like the CEM draw maybe from the alarm siren or the fuel door actuator which I removed a while back due to it being locked shut.

RockOcean · Post by **RockOcean** » 29 Aug 2022, 10:28

Looks like pulling the siren fuse #38 sorted the #32 CEM draw. Hopefully I'm good to go now, just gotta change the steering rack and the shocks all around. Thanks again!

Post by **jonesg** » 29 Aug 2022, 13:11

RockOcean wrote: ↑29 Aug 2022, 10:28 Looks like pulling the siren fuse #38 sorted the #32 CEM draw. Hopefully I'm good to go now, just gotta change the steering rack and the shocks all around. Thanks again!

just gotta change the steering rack.....
I'd rather hand lap the cyl head.