Hello, I installed a 2014 prius drivetrain in my 1993 MR2. It runs great and gets 45-50 mpg. I have an issue with my combo meter, the speedometer and odometer do not read, but I get the readings thru the OBDII port. I have tried a couple of combo meters with the same results. I do have a few faults for missing units, power brake and steering units and the restraint unit. Any ideas??? Thank you
This sure sounds interesting. Definitely need photos. It would be great if you could discuss problems you ran into and how you solved them. I couldn't imagine installing a Prius engine/transaxle and HV system and not having dozens of problems pop up since every system in the car is so integrated. Wish I could give you some advice on the issues you're seeing now.
Should I assume you have techstream? Because if you did the conversion without techstream, I'll be at a loss for words. Shop manuals MR2/prius would be another minimum if I were attempting that conversion.
Since when do MR2’s have combo meters? My 91 (same gen) had analog gauges. And aren’t 93’s OBD1? And how did you get the car smogged in California? You can’t even use an aftermarket cat in California, much less a different engine.
@Bill the Engineer may have some ideas. He has started putting his 1968 Firebird convertible on a Prius v chassis. He calls it the Firebrid. Firebrid: The Prius v Powered Hybrid Convertible | PriusChat
That sounds like an idea that I had. I wanted to put it in a Spyder MR2. But that still sounds like a lot of fun.
Welcome to PriusChat! You are having a similar problem to the one I had trying to connect a Lexus HS250h speedometer to the Prius v wiring in my Firebrid. While Toyota uses the same connector across multiple models of cars, the wire assignments for various functions differ. It takes an electronics engineer to figure out which wire moves to which pin. If you used the Prius wiring harness and computers, I would guess that temporarily connecting the speedometer from a same vintage Prius would solve some of the issues. If you used the MR2 harnesses, you have a harder task. The way many of the systems work in a Prius is quite different than a conventional car. The control and sensor signals are different. There also won't be the necessary wiring for the hybrid system. The cooling fan in the traction battery is CRITICAL to keep the battery from failing. Please provide more details on your conversion and perhaps the crew here can solve some of your issues. Bill
If the “power brake” unit that’s missing is the skid control ECU, part of the Prius brake actuator assembly, that’s why the speedometer doesn’t work. The New Car Features book (more info) for the 2014 Prius says that the vehicle speed signal used by the combination meter assembly comes from the skid control ECU. Without this ECU connected to the CAN (V1) bus and to the four wheel speed sensors, the speedometer won’t work. See also the “Speedometer Malfunction” topic in the Repair Manual. The vehicle speed from the power management control ECU is separate; it’s available as long as the motor generator ECU is providing a resolver vehicle speed signal, but it’s also not used by the combination meter.
Sorry but my Bull Crap meter is in the red on this one. 45-50 MPG? It’s quite impossible to get a car smogged in California with the incorrect smog devices and plumbing. You will fail for having one vacuum line not connected, I know it’s happened to me. You can’t operate a car with a non approved engine in Ca, just not happening. Guy is new, one post.
If it’s from a 2014 Prius, the engine has been certified (PDF), though. That’s true, at least in principle, but it is allowed to replace an engine with another approved one, as long as the requirements in the official Engine Change Guidelines (PDF) are met. A visit to a BAR Referee would be needed the first time, but after that, if the emission control equipment is working, the car should pass a Smog Check.
Hello, I am using the prius computers, gauges and wiring harness. Thank you for the info on the skid control, I have thought it was that but have not gotten to that on my list. I do have a few issues before I can get it smogged. I have all the prius hardware but the gas tank. I installed the prius dash. I have the MR2 brains for the body and the Prius brains for engine, Transmission, battery, hybrid, skid control, AC, main power.
