How do you bypass a chipped key circuit to start a 1996 Chevy Lumina after swapping engines?

Question

I recently swapped engines - a 1991 Lumina engine was put in a 1996 Lumina. The car won't start. It has a chipped key. How do you bypass this circuit?

Answer 1

There is a way to bypass it, but I don't know the exact steps to do so.

You don't say if it never started after the engine swap, if it started for a while after the engine swap, or if the problem was there before the engine swap.

Of course, if this problem was there prior to the engine swap, or if it started for a while after the swap, then it is likely due to the ignition cylinder wires being broken. This is the most common problem with the passlock system, the wires from the cylinder break over time from being twisted on and off so many times during the years. When the wires break, it won't be able to read the resistance from the key and the security system activates, preventing the vehicle from starting. The only way to fix this is to replace the ignition cylinder with a new one (the wires usually break right at the cylinder), or bypass it.

If it never started after the engine swap, then your problem is likely something other than the security system.

Answer 2

It cannot be bypassed, this is a passlock-1 system. The PCM from the two cars are not compatible with each other. You would have to use the entire body and engine electrical system from the 1991 i order to get that system working. The computer is designed to prevent starting when it thinks the systems have been tampered with.