OBD wire loom question-Upgrades-ideas-rambling without coffee..

[mrmustang]

May or may not be specific to my 1.6L Sigma engine, but does anyone know if the 2013 Caterham engine loom had an OBD or OBD2 connection?

 

Any assistance to the above would be greatly appreciated.

 

Sincerely,

 

Bill S.

Edited August 22, 2021 by mrmustang

[mrmustang]

I rarely respond to my own post, but Rick from Time Machines Motorsports in NY gave me the following excellent information:

 

"The read port is in the left foot well behind a 3" rubber plug. It is OBD style but OBD will not read it. The software is "Easimap" and requires an app (not a program) to read it and a proprietary cable to connect."

 

Tried finding the Easimap ap in the apple store, but did not find it there. I did however find it via Google and now will learn as much as I can.

 

Bill S.

 

 

[Croc]

 

@mrmustangYour car should have a MBE 9A4 ECU?  The plug is J1962 which is the same as OBD2.  However, the pin outs are different.  The output is CAN.  OBD2 is CAN too but not all CAN is OBD2 which is the case of the Caterham MBE ECUs.

 

Older Caterhams with zetecs often used the Ford ECU which could be plugged into an OBD2 reader.  Plenty of error codes would show (e.g. lack of original gas tank, emissions equipment, etc) but you could see engine codes to diagnose errors.  

 

Easimap is a tuning tool.  

EASIMAP 6 PC Software (sbdmotorsport.co.uk)

 

To use it obviously you download but you need to buy the expensive cable between computer and ECU from SBD exclusively - it is a proprietary set up.  Enough owners on here have bought one over the years to tune cars that you may be able to borrow one.   Even then you can only look at data on the PC as the car is running.  You cannot change anything without the password.  It will be real time setting data and not error codes like you get with OBD2.  It is really designed to be used in a dyno environment.  Unless you are planning to re-tune the car, its not really worth it.  

 

You can also get the same result with an AIM Solo 2 DL data logger but the advantage here is you can drive and get results better in a live environment which can be helpful for certain types of diagnosis.  In my example below I wanted to test intake temps and oil temps in a real track environment.  When setting up the AIM Solo you will need to specify the ECU as being on a Noble (vehicle).  Noble use the same brand ECUs as Caterham, albeit an upgraded model of ECU.   I was never comfortable all the data was correct - the TPS data looks suspect as does the Lamda.  GPS is slightly off from timing of engine data too.  

 

 

 

I suppose the question is - what are you looking to achieve?

 

 

 

 

 

 

[mrmustang]

3 minutes ago, Croc said:

 

@mrmustang

 

I suppose the question is - what are you looking to achieve?

 

I'd like to find out what is causing the check engine light on the dash to be on

 

Of course with lack of use, it could be as simple as a leak in a vacuum line, a bad injector, or even a bad oxygen sensor, but it would be nice to narrow it down so I'm not tearing down the ancillaries in a "hunt and peck" to find the solution. Any ideas?

 

Rick has graciously offered his cable for this, but it may be a month or so before I catch up with him at Olthoffs  in NC

 

 

Thanks again for your assistance

 

Bill S.

3 minutes ago, Croc said:

 

 

 

 

 

 

 

[Croc]

@mrmustang   Is it a red LED on the base of the speedo?  Or is it on the tach?  Do you have the digital ODO or the old style rolling barrel one?  You have a 2012 car so should be old style pre-2015 speedo with the LED.

 

Caterhams "check engine light" is not as sophisticated as a regular car so it will not alert you to much on the engine other than electrics which is usually somewhere in the alternator line of thinking.     Is it on at start up then goes away?  Or does it stay on and never go off?

 

If it is the same LED light that I am thinking of, then betting odds would have me looking at:

- alternator belt tension

- alternator voltage output

- that the chassis earth is still in place. 

- battery condition

 

If it is on at start up and then eventually goes away after half a minute then that is normal.  

 

[mrmustang]

5 hours ago, Croc said:

@mrmustang   Is it a red LED on the base of the speedo?  Or is it on the tach?  Do you have the digital ODO or the old style rolling barrel one?  You have a 2012 car so should be old style pre-2015 speedo with the LED.

 

Caterhams "check engine light" is not as sophisticated as a regular car so it will not alert you to much on the engine other than electrics which is usually somewhere in the alternator line of thinking.     Is it on at start up then goes away?  Or does it stay on and never go off?

 

If it is the same LED light that I am thinking of, then betting odds would have me looking at:

- alternator belt tension

- alternator voltage output

- that the chassis earth is still in place. 

- battery condition

 

If it is on at start up and then eventually goes away after half a minute then that is normal.  

 

Digital odometer, check engine light on tachometer, see attached picture (car running for several minutes).

 

Have not checked any of the above yet, but will as soon as I can get a cool day to get back in to the garage (107 showing inside just now).

Battery should be ok, as I have yet to charge or plug in trickle charger and it fired right up, even after sitting for almost a month disused. May pull it out and bench test it just to play it safe.

 

Anything else I should be looking for or at?

 

As always, your guidance is much appreciated, as this new fangled, computer controlled stuff is not as fun as pure mechanicals are.

 

 

Bill S.

[Croc]

 

OK - thats a later speedo than I was thinking.  I also just remembered this is a Sigma which is important as the tach is wired into the CAN Bus which is important for why you see a signal.

 

For Sigma cars, supposedly they can provide OBD2 codes for engine only.    Copying from the Caterham User Manual produces the following text:

 

Engine warning - Amber If this lamp illuminates with the engine running it indicates a malfunction within the engine control system. Each malfunction will have a specific code and description and can be read using an OBD generic scan tool. This should be carried out as soon as possible. If engine warning light persists, please seek qualified assistance from Caterham

 

By the way, the Caterham user manuals are located in the Download section of this forum - look for the menu option top left.

 

So I would stick an OBD2 reader on it and see what codes pop for the engine.  

 

I suspect what you will see is a code P0100 Mass Airflow Sensor.  That will not help you as Caterhams do not have one unless you have an EU spec car and that would be unlikely for you. 

 

The end diagnosis seems to be this thread here on Blatchat.

Engine Check Light - MAF Fault | Lotus Seven Club (lotus7.club)

 

it also confirms you should be careful reading Caterham user manuals!  

 

 

A really good article for understanding what signals Caterham ECUs put out was done here:

ECU Diagnostics – part 2 : ECU, OBD and CAN | PurpleMeanie

 

 

 

 

[mrmustang]

Thanks, will dig in as soon as I can and let you know what I find.

 

Bill S