Wiring the iBooster

In 2020 I published this blogpost as “Wiring the Tesla iBooster”. At that time Tesla was an early adapter for the Bosch iBooster. Now (January 2024) it is time to update this blogpost to “Wiring the iBooster”. Many other OEM’s are now also using the iBooster. While the CAN messages are all different, many OEM’s use the same wiring. But nowadays differences start to emerge. I’ve seen the following variations: :

  1. Tesla, Honda, Volkswagen, etc
  2. Toyota Yaris (Gen 2, also different travel sensor connector)
  3. Renault Zoe
  4. Peugeot 5008 / 308 / Citroen DS7

I will gradually expand this blogpost and explain wiring and other differences between models from the various donors. Any info you have on this is welcome!

Wiring the iBooster made easy

Most iBoosters you can buy on eBay or elsewhere come without connectors. If you are lucky they do come with connectors and a bit of wiring. In that case you will still need to extend wires and attach them to your wiring loom. And where to connect which wire to what anyway? This article explains the ins and outs of wiring the Tesla iBooster and from other OEM’s into your car.

It becomes quite straightforward using the GEN1 connector kit and the GEN2 connector kit available from EVcreate with all connectors, terminals / crimp pins, seals and blind plugs. Moreover you will be able to fully integrate the iBooster into your wiring loom.

Stand alone mode: no CAN-BUS needed

The iBooster ECU has two CAN-BUS connections which are connected to the vehicle CAN and the Yaw sensor. Here these two are not used and instead of crimp pins, blind plugs are provided in the connector kits. Instead we rely on the ‘failsafe mode’ of the iBooster. In that mode the iBooster just uses the input from the travel pedal sensor (integrated onto the iBooster) to operate. Furthermore it requires 12V+ and GND inputs. Below it will be explained in more detail. It is possible to control the iBooster over CAN, we’ll dive into that in the future. Any input or experience on that is welcome.

To a large extent the wiring of the GEN1 and GEN2 is identical. Main difference is that the GEN2 no longer uses pin 17 for permanent 12V+ to the ECU and above all the travel sensor connector and it’s pin numbering is different. The travel sensor itself is part of the iBooster assembly, see below photo’s. It just is not internally connected so you need to wire it.

Travel sensor iBooster Gen1
Travel sensor iBooster Gen1
Travel sensor iBooster Gen2
Travel sensor iBooster Gen2

Below you will find detailed wiring and pinout instructions for both.

GEN1 iBooster wiring

iBooster ECU connector wire insertion view
Wire insertion view

Electronic Control Unit (ECU)

  • 1 = 12V+ permanent 40A fused
  • 2 = Pedal sensor 1
  • 8 = Pedal sensor 3
  • 9 = GND
  • 17 = 12V+ permanent 5A fused
  • 20 = 12V+ ignition 5A fused
  • 22 = Pedal sensor 2
  • 23 = Pedal sensor 4
iBooster pedal sensor connector

Travel sensor

  1. to ECU 2
  2. to ECU 22
  3. to ECU 8
  4. to ECU 23

Recommended wire sizes

Firstly de main power pins (1 and 9) which are the largest terminals (4.8 spade) and are intended for 2,5 – 4 mm² wire (Tesla uses 4 mm2) and the seal included in the kit accepts an outer diameter of Ø3.4 – Ø3.7 mm. Secondly pin 17 (the additional 12V+ permanent) which is the medium terminal (2.8 spade) and is for 1,5 – 2,5 mm² wire and the seal is for Ø2.0 – Ø2.7 mm. Finally the small terminals (1.5 spade) for the 12V from the ignition and the pedal travel sensor accept 0.35 – 0.5 mm² wire and Ø1.6 – Ø1.9 for the seal. Unused entries can be closed off with the appropriate blind plugs.

GEN2 iBooster wiring

iBooster ECU connector wire insertion view
Wire insertion view
  • 1 = 12V+ permanent 40A fused
  • 2 = Pedal sensor 2
  • 8 = Pedal sensor 4
  • 9 = GND
  • 20 = 12V+ ignition 5A fused
  • 22 = Pedal sensor 1
  • 23 = Pedal sensor 3
GEN2 iBooster pedal sensor connector
  1. ECU 22
  2. ECU 2
  3. ECU 23
  4. ECU 8

Firstly identical to the GEN1, pin 1 and 9 are the large terminals (4.8 spade) and are intended for 2,5 – 4 mm² wire (Tesla uses 4 mm2) and the seal included in the kit accepts an outer diameter of Ø3.4 – Ø3.7 mm. The GEN2 iBooster does not use pin 17 (medium size terminal). Secondly the small terminals (1.5 spade) for the 12V from the ignition and the pedal travel sensor accept 0.35 – 0.5 mm² wire and Ø1.6 – Ø1.9 for the seal. Finally again, for unused entries the connector kit contains appropriate blind plugs.

iBooster power draw

Tesla uses a 40A fuse for the main power input and 5A for the ignition and in case of the GEN1 the secondary 12V permanent. For the GEN1 after switching the ignition off the current shortly still is 250 mA and then drops to 1,2 mA.

Blog series on power brakes

  1. Vacuum assisted power brakes
  2. Electric power brakes
  3. Installing the iBooster
  4. Wiring the Tesla iBooster
  5. Performance test of the Tesla iBooster
  6. CAN control of the iBooster
  7. Other iBooster donor vehicles

Disclaimer/warning that is not only valid for this article but applies in general.

It is the sole responsibility of the person or company selecting or installing any component or kit in any car modification or upgrade (like brakes, drivetrain, etcetera) to determine the suitability of the component or kit for that particular application. Especially when using parts or components that were not directly designed for use in that specific brand or model. If you are not sure how to safely use a part, component or kit, you should not install or use it. Do not assume anything. Inspiration and information found on this website, elsewhere or examples that others are using a part, component or kit does not guarantee proper installation or match with your particular setup.


25 thoughts on “Wiring the iBooster”

    • Thanks! The pedal travel sensor is part of the iBooster. I have updated the blogpost and added photo’s for clarification. This question was asked a lot so apparently not explained well enough so far.

  1. We swapped the gen 2 iBooster into our vehicle .

    We are experiencing the brake pedal to continue to build boost and not release. We will of course dig in and check calipers and lines… but they worked fine before the swap. I wanted to know if you had any thoughts about the issue. This link has mentioned the same issue we are having (https://car.inotgo.com/2021/10/20211011041849532k.html)

    Our gen 2 ibooster is from a 2018 honda accord.

    • Wel, I’ve had the same situation/issue with a GEN1 iBooster.
      I my case it was a misaligned (out of range ?) travel sensor.
      Unfortunately I have not been able to reproduce the issue to further investigate it, but I think this was caused by either the zero position of the pushrod not being within the measurement range of the internal sensor or max pedal travel outside the range of that sensor.
      In my case this was resolved by moving the sensor a bit, but this is not possible for the Gen2 and also not recommended.
      I’d check push rod positions. Hope this helps, please let me (and others) know by replying here if you manage to solve it.

  2. Thanks for an awesome manual!

    There’s one thing I wonder though and that is if you can get brake light output and/or brake signal (0-5V) from the iBooster Gen 2?

    I have started to mess around with it and it seems to work fine so I’m only needing some outputs.


    • Thanks!
      Well, there is no analog or digital output specifically for this. I would not interfere with / tap into the pedal travel signals so that leaves CAN-BUS as the remaining option. I have not checked it for Gen2 but I think that is similar to Gen1 so I expect push rod travel is a parameter on the bus. So you can use that to enable a brake light.
      Check out my iBooster CAN-BUS research blogpost for further information.

  3. on the bench it works occasionally, if I keep the rod pressed while I give tension, it starts, but it goes without the wire locked, and then it stops after a while. Maybe I have to install it and so does the pedal calibration because I read above that the 0 position is not good. I leave you the link of the 2 videos. the first when it works and the second when it stops working.https://photos.app.goo.gl/GBUh3qe4v3BztYF49

  4. I did other tests, it works if I connect pin 20 for a moment and immediately disconnect it. so it works, if I connect the pin 20, it stops working and then it moves a bit. you can see it in the video. maybe once mounted in the car and done the calibration, then it’s fine, I hope.
    Now I’m wondering if I’ve made the right connections. https://photos.app.goo.gl/YhjGe7eopAcFnnKh8

    • See paragraph 4 of this article:

      The travel sensor itself is part of the iBooster assembly, see below photo’s. It just is not internally connected so you need to wire it.

  5. I put the iBooster renault captur into operation, it was sufficient to connect it to the can bus, and it started to work like the ones you tested, if the car does not have the can bus, then just connect the two can outputs of the ibooster with a resistance of 60 ohm. or 2 of 120. Then I configured torque, orion bms, and I see on torque how many mm the brake is pressed….cool.
    Thanks to your site I was able to do it.
    Thank you

  6. Thanks for these blog posts. I finished installing the ibooster into my EV conversion a few weeks ago. Today I finally took it on an extended drive and came across an interesting issue. At some point, on the freeway, I noticed my brakes were stuck on. As in the booster was applying brakes when I was not. It didn’t release until I disconnected power from the ibooster. Reconnecting the ibooster in fail-safe mode, it resumed working as usual. Have you heard of this before? I only experienced it once so far and so I’m still observing if it occurs again but it caught me by surprise today.

    • Well, actually I had the exact same issue. Think this is caused by travel sensor position at IDLE and calibration of the iBooster travel sensor when you power the iBooster up. I solved it by slightly moving the travel sensor but this is not the best solution. But in our case we were on our way to the ferry and there was no other option.
      Think the structural solution is to adjust the push rod length.

        • Don’t remember in which direction I adjusted the sensor, but I would not recommend that. Adjusting your push rod seems the way forward to me.

          • misc fyi. I adjusted my push rod and it fixed the issue. I had extended the push rod originally but shortening it back to stock length fixed the issue.

            fyi to others who read comments, I used the Gen1 CR-V variant of the ibooster on a Honda CRX 1986. The bolt pattern matches but bolts need to be extended. I removed the bolts and put in longer bolts. I originally also extended the pushrod but thats unnecessary. The push rod is actually perfect length to bind with the CRX stock brake pedal.

  7. Do you have any details on how the travel sensor works?

    I’ve got a brake pressure sensor for my Hyper 9 EV conversion (0-5v input/output signal) and if I’m able to use the travel sensor as an alternative that’d be great!

    • Unfortunately I did not measure the voltage profile but I do know it is a dual hall sensor.
      Most of these sensors have an output from a voltage between 0 and 1 (not 0) up to something between 4 and 5 (not 5).
      If I have time I’ll test.
      But I expect it is not suitable as a drop in replacement for the 0-5V pressure transducer due to the offset (not 0V at IDLE).

  8. Hello Lars,

    What wiring harness do I need for 2012-2020 TESLA MODEL S Power Brake Booster 1037123-00-B OEM? I’m looking at installing in my jeep.

  9. Thank you for the info.
    Are you familiar with any recovery mode or else which ibooster can enter?
    I had a bad contact on the power and ignition to ibooster gen2. It toggled the ibooster on and off within a few seconds. After fixing it, when I power it and apply ignition, it doesn’t start. Before there was a very distinct sound when it started. I connected the CAN bus to see if any messages reveal anything, but nothing is coming out.
    I hope the unit isn’t damaged. 🙁

      • Ok it wasn’t broken. It was related to the CAN bus. I had CANL and CANH swapped. All works now and reports to CAN.
        But the interesting thing is, if he CAN bus is disconnected – ibooster works; if CAN bus is connected properly – ibooster works; if CAN bus connected improperly (in my case CANL and CANH swapped) – ibooster doesn’t work – practically zero current consumption on the power on and doesn’t respond to ignition signal!

        I did notice that in the fully released state it reports the stroke length as 38mm. When I gently press the pedal it reports few mm of the length. The more I press, the more mm it reports. In my case fully pressed – 44mm. Releasing the pedal goes to 38mm. Should then the ibooster be preloaded so that in the fully released state it reports 0mm?


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