Howdy Guys Cruise Control On A Prius

Hi Kelvin and welcome to Prius Chat. I can't answer your question but, in UK in 5 hours ahead of USA and most of the tech knowledge is over there. Hold on and someone like @Elektroingenieur will come back to you, hopefully with good news.

 

I don’t have an answer for the question, but I can share some background information.

Toyota seems to have built fourth-generation Prius cars (2016 and later; ZVW5# series) with one of three cruise control configurations, depending on the destination country and trim level (grade or model):

• No cruise control at all;
• Conventional cruise control, with constant speed control mode only; or
• Dynamic radar cruise control (also called adaptive cruise control), with both constant speed control mode and vehicle-to-vehicle distance control mode.

On the Prius, dynamic radar cruise control is a feature of the Toyota Safety Sense-P (TSS-P) system; it uses the forward recognition camera, millimeter wave radar sensor, and driving support ECU found only on cars with TSS-P. I doubt it would be cost-effective to retrofit TSS-P to a car that wasn’t built with it: besides adding these and other parts, you’d most likely have to replace several of the main wire harnesses.

I don’t know much about adding conventional cruise control. This question doesn’t come up in the U.S., since all fourth-generation Prius cars sold here have conventional cruise control or TSS-P as standard equipment. As far as I know, Toyota doesn’t offer cruise control as a dealer-installed option for the fourth-generation Prius in Japan or Europe, but it might be different in smaller markets.

On cars that have one, the cruise control main switch on the steering column is connected between chassis ground and the CCS terminal on the hybrid vehicle ECU, via the cruise control switch wire and the spiral cable. I don’t know how the hybrid vehicle ECU determines what to do when it receives a CCS input, nor how this might differ among the hybrid vehicle ECUs used in vehicles built for different markets.

If you’re buying a car that was built for domestic sale in Japan, be aware that conventional cruise control doesn’t seem to exist on the fourth-generation Prius there; it’s TSS-P or nothing. The Japanese editions of the Owner’s Manual, Repair Manual, and New Car Features books all omit the discussion of conventional cruise control found in the U.S. and European editions, and parts catalog entries for the cruise control main switch and wire have the note “Toyota Safety Sense-有り” (= Toyota Safety Sense present), indicating that the parts aren’t used at all on cars without TSS-P.

 

Thank you for another comprehensive and enlightening post.

 

You might be able to get at cruise control functions through the ODB2 port with an app. The obvious downside is you have to screw around with a phone at highway speeds.

The Arduino forums have threads on this, but no clear direction.

There are hardware aftermarket solutions that intercept the gas pedal, those require a kludge of wires.