I haven't run my truck for a few days.(24valve Tried to start it this morning..completely dead. Also found out I had a positive battery connection that was garbage... IN THE MEANTIME,..I jump started it and as soon as I pulled the jumpers off it quit (which is how I found the bad positive connection on the battery). . So,it also threw a code at that time...."tachometer circuit low voltage". Anyway,.It's been running about 30 minutes (14.3 ish volts) and I've tried to erase the code with my scanner and it won't do it (my scanner does not appear to have a "system voltage" readout for this particular truck...is that odd or what?)...with this truck...a little odd....it reads system voltage on all my other vehicles). Anybody have any ideas on this? It's seems odd to me that the check engine light stays on and the code stays in. It is like my code reader knows the code is there, but plays stupid on anything about the code. . My tach. is fine. My voltage is fine. Anybody have any ideas? I may try my hardwired scanner just to see if it's different.

 

Takes a few starts and it should clear. Forget what it's called but engine will need to fully warm up to consider a "good" event to clear code. Mine just did this after a low charge on the batteries.....

 

My main concern was that I was not able to clear the code with my scanner. I also tried to clear the code with my hardwired scanner but it also did not clear the code. I have had this truck for a gazillion years and this is the first time the check engine light has even been on. So I have no real-life knowledge that either one of my scanners will clear this 24V code.

 

Same thing here. My check light came on and it threw a few low voltage codes. I don't have a scanner, I just reviewed the issues in the FSM and it said it would clear after the voltage was up after a few quality runs....never has happened before.