Well this thread has gotten a little of the initial question asked. That the accelerator voltage is too high giving a code. If the accelerator sensor is properly checked and found to be in good shape and properly adjusted then the problem is probably the voltage regulator circuit in the card is defective and the only solution is to replace the card.

I HIGHLY AGREE with the first post....find another service dealer.

Now about the Toyotas. I worked for the Toyota factory or was associated with Toyota for 25 years. The 4Y engine was introduced in the 5 series in October 1986. It has been an unbelievably reliable engine. The SAS system is also extremely reliable, however it is not trouble free. It is expensive to replace components when they fail. That being said....Toyota is the most trouble free truck on the market today. With the changes on the 8 series, I expect the reliability to increase.