Re: clearing codes
Reply #19 –
That's the weird part. The second group should be erased with the jumper pull, and shouldn't show up until the truck has been run again. I assume it has an electic fuel pump like ours... when you pull the jumper during the codes, does the pump run for a second while the computer (supposedly) resets and erases itself?
On the other hand, could those possible voltage spikes (that you said screwed with the voltmeter and tach) have zapped the computer, and now it can't be erased?