Quick question:

Was there an ECU made for California cars?

Thanks,
Josh

 

The earlier models, yes. The ECU difference had to do with the EGR.

 

Correct me if I'm wrong.. but I've heard that only 93 CA ECU is different from all other.. I know 95 EGR is removed.. but not sure about 94..

 

I believe there were slight tweaks with the ECU firmware as well. I know there is a TSB for the '93s, and any of the revised ECUs that were installed by dealers have an "R" at the end of the part number.

In '93, there were California and non-California ECUs - the only difference being the Cali ECUs had the feedback circuit for the EGR valve to tell if the valve isn't working right. All '94s are basically California ECUs with the EGR feedback. In '95, I *think* they did away with EGR all together - not sure there.

I know the Japanese ECU's are slightly different, as NONE of the Japanese cars had EGR or AWS - that was added for US emissions. In '96, the ECU was bigtime revised in Japan, and it's totally not compatible with the '93-95 harness. The ECU was revised again in '99, and is again not plug-in compatible with any of the earlier harnesses.

Dale

 

You got it right, no EGR circuit in '95.

 

If you got the right wiring harness and the most current ECU (1999+), would it work with our engines here in the USA ?

Would it even be worth the conversion with the PowerFC available ?

:-) neil

 

Thanks guys.

 

I don't think so.. I think PFC is better than 99+ ecu.. And cost will be less.. unless you get one used.

 

so what about the 95 changed that they no longer needed the EGR?

 

I think emissions laws changed in '95 and they could get away with not having EGR. Mazda has been weird about EGR in the states - the '86-88 RX-7's all had EGR, the '89-91s didn't.

To answer Neil's question - you could MAYBE retrofit a '93-95 car with the later ECU and harness, but that's one SERIOUSLY tricky job. In '96, they replaced the solenoid rack with a "black box" that simplified the vacuum system greatly - you'd need that, the new vacuum lines, the new coil bracket, etc. Then, it's not 100% if any of the '93-95 sensors work with any of the later ECU's - nobody really knows. The best way to tackle it would be with a full front clip so you could test everything and have all the parts. But, at the end of the day, you could just get a PowerFC which is light years better .

Dale

 

So you can swap ECUs w/o any issues? Ie a 94 ECU for a 5-spd non-cali into a 93 5-spd non-cali w/ no issues, right?

Thanks
~Ramy

 

Actually that would cause a problem because the '94 ECU will look for the EGR circuit which the '93 non-cali car doesn't have. You could go the other way though.

 

So it'll throw a code for the EGR, lighting up the CEL, right? But other than that everything should work?

 

As far as I know, that should be the only problem. I doubt it would throw the ECU into limp mode because the EGR isn't critical to keeping the engine alive like the OMP or MAP sensor.

 

Thanks