IMPORTANT NOTE:
OUR HYBRID OBDII AND STD OBDII CABLES DO NOT DISABLE ABS!
THIS ARTICLE ONLY DISCUSSES OBDI DATALOGGING CABLES FOR 1990-1993/94 VEHICLES!

QU: DO YOUR SERIAL OBDI DATALOGGING CABLES AND KITS FOR 1990-1993/94 VEHICLES DISABLE THE ABS?

The honest answer is Yes and No, although this is not terribly helpful.

I will summarise very quickly now and then discuss in more detail below. Our second generation v2.x Serial OBDI Datalogging Cables when used with our Hand Held Halo OBDI Datalogger Software v2.x or above DO NOT disable ABS. They are true Auto On/Off cables (ref. below) with seamless software control to re-enable ABS without any user intervention.

Our very high quality yet cost effective first generation v1.x OBDI datalogging cables when correctly connected between car and PC will disable ABS and for safety reasons this is made very clear in our instructions. Driver caution is always advised! However by simply disconnecting the inline XLR and reconnecting it you will re-enable your ABS. Again driver discretion is always advised and assuming you know your ABS light to be working, please make sure it goes off when you disconnect/reconnect the XLR plug.

To be perfectly honest, any serial obdi datalogging cable will re-enable ABS if disconnected and then reconnected. So, if you've made your own simple datalogging cable this is how you would re-enable ABS!

---------------------------------------------------------------------------------------------
---------------------------------------------------------------------------------------------

THE ISSUE
When datalogging many OBDI vehicles the act of connecting the car to a PC with a datalogging cable will put the cars ECU into diagnostic mode. A side effect of the car going into diagnostic mode is the fact that the ABS is disabled. Perhaps unsurprisingly this is generally considered an unwanted side effect by most owners particularly those that want to aggressively load their cars during testing. Obviously, when diagnosing or monitoring a static vehicle, disabling the ABS is of no consequence.

SERIAL OBDI DATALOGGGING CABLES
These basically fall into two camps, cables that have the facility to re-enable ABS and those that don’t. A common and fairly unsophisticated way of re-enabling ABS is to have a header switch on the 9-pin D-Type connector, which when switched will effectively disconnect and then reconnect the PC to the ECU. By breaking the connection with the car and then reconnecting in this way you are re-enabling the ABS. Our concerns with this design is the fact they generally have very poor build quality and they usually do not indicate the status of the on/off switch. They therefore rely very heavily on user-intervention and some understanding as to the position of the switch and the condition of your ABS. If you have a faulty ABS light or are unsure about the switch position there is always the risk that you wrongly assume you have taken the car out of diagnostic mode. We consider this an unacceptable risk and would not recommend these cables.

There is a slightly more sophisticated version of this cable, which is a true Auto On/Off cable that does not require any user intervention and will automatically disconnect and reconnect to the car using some basic logic circuitry in the cable. If the components in the cable fail for any reason the connection to the car fails which ensures the ABS is enabled at all times. From our perspective this cable is a safer and more sensible option than the header switch system as safety must be paramount at all times and reliance on users (..many who may be new to datalogging) knowing or making decisions with regards to switching and/or ABS status introduces an element of unacceptable risk.

Our very high quality 2-part v1.x serial OBDI cables do not pretend to be something they are not; if you want to physically re-enable your ABS once connected to your PC it can be done safely and effectively by simply disconnecting/reconnecting the XLR plug. The additional design benefit of being able to effectively replace the OBDI connector with our short length XLR adapter cable means all future connections to the ECU are safe and simple. The short length adapter cable stays permanently fitted to the cars OBDI port and will not disable the ABS…..nice!

As already mentioned in the introduction to this article our next generation v2.x serial datalogging cables are true Auto On/Off cables, with seamless software control to re-enable ABS without any user intervention.
---------------------------------------------------
EDIT APRIL 07:
PLEASE NOTE THE USB CABLE DESCRIBED BELOW HAS NOW BEEN SUPERSEDED BY OUR AUTO ON/OFF v2.x SERIAL CABLES + USB ADAPTER WHICH WORK IN EXACTLY THE SAME WAY!
USB OBDI DATALOGGING CABLES
Dissatisfied with all of the available auto on/off design solutions and realising there was a total absence of any USB OBDI support we thought we would produce the first and only truly intelligent software controlled Auto On/Off solution. Our OBDI USB cables in combination with the Hand Held Halo OBDI USB Datalogging Software incorporate a true Auto On/Off feature. Safety has always been of paramount importance to us and a datalogging solution that intelligently and seamlessly re-enables ABS without the need for manual switching or user interpretation is unequivocally the best and safest option currently available.
----------------------------------------------------

I hope you have found this article informative and if you believe it to be incorrect in any way please let me know and I will post corrections as appropriate?

Many Thanks,
Neil