Telsa on Board Diagnostics OBD-II

The Lotus had a LCD screen with BMS info. There was a lot of info on cell level about temperture and voltage level. The Tesla Model S doesn’t inform the driver with any information about the battery other than de SOC (state of charge). To get to this information you have to access the CAN-bus and read the CAN messages. To do so you need to find the diagnostic connector which is behind the shelf just beneath the main screen.

Telsa diagnostic connector

Telsa diagnostic connector

Tesla uses a proprietary connector instead of the standard OBD-II connector. Most diagnostic interfaces come with the OBD-II connector so an adapter cable is needed.

Model S Adapter cable

Model S Adapter cable

To see the CAN-bus info you need software that is capable of translating the Tesla CAN messages. You can use Scan My Tesla for Android or TM-Spy for Apple. Since I have an Android Phone I went for Scan My Tesla and bought a OBDLink MX ABD-II adapter.


OBDLink MX with cable



The Lotus could charge on a standard CEE plug with max 32A on one fase. The Tesla has a duo charger which can handle 3x32A (3x32Ax230V equals 22KW) but it needs a Mennekes type plug with CP and PP contact. I could have gone the easy way and purchase a Tesla Wall Connector for nothing less than €530,- or any other 22KW charger, but I would like to know if I could build one myself for less. sells a EVSE kit for €50,- which is basically a board based on PIC micro controller which is able to generate 1KHz PWM Signal to detect the vehicle and control the relay.

parts needed:

  • GWL/Power EVSE Kit v1.1 for EV charging station/cable (Wallbox) – kit only
  • Relay capable of switching 230V/32A
  • mennekes type 2 female plug
  • 220 Ohm resistor
  • 5X6mm2 with wire for CP signal
  • Housing
EVSE schematic

EVSE schematic

Installed end result with a temporary charge cable and CP wire ( I didn’t have the right 5G6 + 2×0,75mm charge cable)


Plugged in to the Model S

Model S chargeport

Charging at 22KW

3x32A charging

3x32A charging



New project car

I found a 2010 Golf Variant which had an E-license. This Golf is one of 45 build by ECE, the same company which converted the Lotus to EV. Unfortunately al the EV part where removed. So basically we bought a body with a registration number (licenseplate).

I contacted my EV repairshop if they could restore the car with original parts. I everything goed as planned the Golf will run end of January 2018


2010 Golf Variant 06-JND-2

Engine bay

2010 Golf Variant 06-JND-2 enigne bay

ChaDeMo diagnostics

So far I wasn’t able to fast charge my test pack. First I thought it had to do with fact that the JLD505 wiring was somewhat different than the schematic in the ChaDeMo Kit Manual because it has been used in a Zero motorcycle. The logging showed that the High voltage contactor was closed and that the EVSE supplied a high voltage. But after a few seconds the voltage rose to the max battery voltage set in the JLD505 and the EVSE stopped the charging process. Based on the ChaDeMo charging sequence flowchart I came to the conclusion that the JLD505 is working fine. But the test pack is probably causing problems. The test pack has old batteries from an UPS and they weren’t designed for fast charging.

The JLD505

The JLD505 module consists of a single two-layer printed circuit board mounted in a
Modice Cinch LE weatherproof enclosure.
This module is compatible with the Arduino Uno multicrontroller board and uses the
Arduino Integrated Development Environment for programming.
The heart of the module is an ATMEGA328P-AU 16 MHz multicontroller. The highperformance Atmel picoPower 8-bit AVR RISC-based microcontroller combines 32KB ISP flash memory with read-while-write capabilities, 1024B EEPROM, 2KB SRAM, 23 general purpose I/O lines, 32 general purpose working registers, three flexible timer/counters with compare modes, internal and external interrupts, serial
programmable USART, a byte-oriented 2-wire serial interface, SPI serial port, a 6-
channel 10-bit A/D converter (8-channels in TQFP and QFN/MLF packages),
programmable watchdog timer with internal oscillator, and five software selectable power saving modes. The device operates between 1.8-5.5 volts.
By executing powerful instructions in a single clock cycle, the device achieves

JLD505 manual

The EVTV CHAdeMO Fast Charge Kit includes the following components:
• 1 CHAdeMO Fast Charge Inlet and wiring harness.
• 1 JLD505 Charge Controller
• 1 Cinch Connector and Pin Set
• 2 Gigavac High Voltage Contactor Relays
• 1 12v Relay
• 1 DS18B20 Temperature Sensor Probe
• 1 400A 50mv 0.1% calibrated shunt
• 1 USB Connection Cable

ChaDeMo testing at FastNed fail

Only 10 Km from where I am there is an ChaDeMo charge station owned by FastNed. With the battery pack loaded into the Land Rover I headed to the charging station.

Battery pack in the back of the Land Rover

The first test gave some result but no charging took place. After 4 seconds the charging stopped.

First ChaDeMo charge session failed

ChaDeMo project continued

One year ago I started with the ChaDeMo project. I build a test battery pack but wasn’t able to get my hands on a JLD505. The JLD505 was developed in 2015 and sold by EVTV. Unfortunately they discontinued the JLD505. A few weeks ago I was able to buy an used JLD505. Unfortunately it is modified to be used in a Zero motorcycle.

Zero motorcycle

After some modification I was able to connect the JLD505 to my test pack.




Battery test pack and JLD505