Hi all, I'm struggling to get cruise control working on my Toyota Prius gen 2 1.5L, it's a japan import. I bought below kit CC kit from aliexpress, installed it and I can see switch working OK from my OBD scanner but the cruise control light doesn't come on the dash board, doing some troubleshooting i found that there is no output from ST1 on the ECU - this is the required voltage to activate tthe cruise contrl once switch is pressed. Also my brake light switch in the car is 2 pins which is not the correct switch, I bought the 4 pins switch but I'm not sure how to wire it? Any idea how I can fix that? Thanks Mina
When I added cruise to my Gen 1, I found that the wiring was already prepared for a four-pin brake switch (the connector from the wiring harness had four wires), so I only had to swap out the old two-in switch for the four-pin switch that came in the kit, and it plugged right in. If the Gen 2 wire harness isn't like that, you'd have to refer to the wiring diagram and get some wire and terminals to add the missing circuit.
First thing I would do is take the four ("4") pin switch to the bench and analyze it using an ohm-meter. With four contacts on the brake switches you should have two ("2") separate circuits. One pair of contacts (which we shall call "Pair1") should have nil resistance (when measured with ohm-meter*) when brake pedal is depressed. IOW, current flows when brake pedal is depressed (generally this what turns on the brake lights). Second pair of contacts (which we shall call "Pair2") should have nil resistance (when measured with ohm-meter*) when brake pedal is NOT depressed. IOW, current flows when brake pedal is NOT depressed (generally this conductor is used to power the cruise control system). *- NEVER use ohm-meter on a circuit with power (thus, take the four ("4") pin switch to the bench w/o 12V power).
the brake switch in the car has two pins, the one I bought has four and I did that test and can see the two different circuits which from the wiring diagram is one from the stop light switch while the other for the cruise control the issue is to activate the one for the cruise control I need output voltage (12V) from the ECU which I can't get, any idea how to activate the option?
My understanding is that you are installing a standalone (IOW, the kit is built to fit in many different cars) cruise control kit. If so, it would seem that the 12V feed when brake is NOT actuated (AKA "Pair2") could be pulled from almost anywhere (my preference being 12V hot only when ignition is in run position). As far as getting the cruise bulb to light on dash in stock position, I would try to get an after-market two cent ("$0.02") LED to light when cruise control is engaged. Once you get the CC working with the exception of the stock dash light then you can dig into that issue.
I think you were absolutely right, I tested 12V direct to the car ECU H15-2 but the dashboard didn't come on but I suspected maybe there is no LED in the car which was the case I took the car on a dangerous test drive - because CC will not disengage when I press the brake pedal - and it worked then I tested the proper wiring from driver side J/B pin A27 to ECU pin H15-2 and again work OK Now I need to install CC dashboard LED and manage to install the CC wire through the brake switch Once again thanks mate
I am happy to hear that you are getting this problem solved. You should be proud of yourself for drilling down and getting this thing figured out in steps. Be careful with that non-disengageable cruise control (IOW, do not use again until you get four pin brake switch wired so that applying brake cuts out power to cruise control). Let us all know how you progress on this project.
Forgot to mention, I found the correct brake switch (I think I bought that last year) and installed it yesterday. everything working as it should I think the lock-down we have in New Zealand is giving me enough time to finish all few month old projects Thanks mate
Great.. I did same mod (my first DIY) 2 years back in my 06 japanese import. Mine also didn't have LED so I installed it. Be careful about LED color matching because mine has slightly different color and I don't want to open the dashboard again... This is a comparatively simple and encouraging mod. Later I did few more and realised that this car is far more easier and friendly for DIY jobs unless you do a head unit upgrade (which I did and lost few functions) because japanese wiring diagrams are very hard to find Posted via the PriusChat mobile app.
Awesome, mate. do you recall what LED did you buy? I'm looking to buy one but not sure also regarding your head unit, you probably lost steering wheel control? I'm looking to upgrade my head unit but I don't want to lose steering wheel control
I have retained all the steering wheel controls with my new HU. All working fine. Regarding LED, I am sorry I don't recall exactly. But yes the color of this LED is a little different.
Unfortunately I can't find the brake switch part number, I bought everything two years ago and didn't install the brake switch at that point. I went through ebay and amazon purchase history but can't find it sorry mate. I will try to get picture of it to high light the difference
found it Stop Light Switch Brake Light Switch OEM:84340 30110 For Toyota PRIUS REIZ MARK X CROWN For LEXUS IS250 SC430 GS300 LS430 RX270|switch brake|switch switch|switch light switch - AliExpress part number 84340-30110
Mina Botrous. Hopefully you get this message. I've recently bought a CC kit for my JAP Gen 2 Prius, it's all installed and I have the correct 4 pin brake switch installed also...however, the brake light switch plug only has 2 wires...I assume it needs 4 because my CC is not functioning. Can you advice me on how it needs to be wired? I'm out of my depth with wiring diagrams and I found the above posts very complex You're the only person I've found online to fix this issue. Please help a fellow kiwi haha.
