How to change a 14CU (US spec.) to a 14CUX ?
2. Upgrading from 14CU to 14CUX is required to accept Tornado or Optimax re-Chipping, if you have 14CU Model ECU (normally only US spec.) it is actually quite easy to convert from 14CU to 14CUX, but of course it does require your customer to purchase a 14CUX ECU as the 14 CU is not upgradeable to Optimax or Tornado. The 14CUX will plug straight in where the 14CU used to be, however, a simple wiring modification is required to make it work. If you are replacing a 13/14CU with a 14CUX and keeping the oxygen sensors, then you do not need a tune resistor as the software types X33, X34, X38 do not look for one. But if you are not using Oxygen Sensors then you must have a tune resistor in place (if in doubt please contact us). This is because the 14CU has no tune resistor. Instead, the pin used for the tune resistor is connected to the air-con system. All that is required is that the wire going to ECU pin 5 from the air-con is cut, and replaced with the correct tune resistor (probably 3900 O
