Third Gen Bypass Speed Limiter

Q: How can I bypass the speed limiter?

A: Try the following steps:

Install a Zemco Performance Timer and instead of using the speed sensor supplied, tap into the electronic output from the normal sensor in the tranny (there shouldn’t be a problem driving two sets of electronics in parallel).

Then fit an ON/OFF switch into the speed sensor wires that goes into the ECM.

Wire the torque converter so it’s not controlled by the ECM, but rather by on ON/OFF circuit switch. This results in non-lockup when the shifter is manually put into 1,2 or 3. Selecting OD will get normal up-shifts without lockup until 4th when lockup comes in. The while in OD, if the tranny downshifts due to speed/throttle settings, the TCC stays locked unless drop it out using the switch (except for 1st gear which doesn’t allow pressure to the TCC anyway due to the hydraulics).

The Zemco unit can be easily recalibrated if you change tire size or rear gear ratios. When you want to push the car past the speed limiter in the ECM, just switch OFF the speed sensor input to the ECM and use the Zemco unit to show your speed. All that happens with the ECM is the normal speedo stops working and you lose cruise control. After about a minute the ECM realizes that the pulses are missing from the sensor and gives you a service engine light. This does not affect the normal operation of the engine and the light goes out again after a few seconds when the sensor is switched back on.