Where is the OBDII socket on the V8?

[bingoking]

Simple question but I don't know the answer.

[sailorbob]

Behind the glovebox.

[bingoking]

Ok thanks

[bingoking]

Well I found the socket and plugged in my scanner but it comes up with a Linking error.

The scanner I am using is a MaxiScan MS300 by Autel, and guess what, I can't find the instruction book.

The scanner works on my Evora and also on my wife's Audi A3 so why not the Esprit?

[march]

There are 2 sockets on the V8 (well there are on mine) - a second one is attached to the side of the relay box in the boot (I tend to use that one). May be worth trying that socket.

[bingoking]

22 hours ago, march said:

There are 2 sockets on the V8 (well there are on mine) - a second one is attached to the side of the relay box in the boot (I tend to use that one). May be worth trying that socket.

Thanks Mark, I did find the other socket but still getting the Linking Error message. Must be my scanner I think.

[LotuStuart]

my 2001/2 model year Esprit does not have a front OBD socket.

Unless someone with an RHD car can pinpoint a location (and prove Sparky and me wrong of course...which I would prefer to only having one!) I'm a bit stumped.

 

[Sparky]

I went so far in, I needed a rope tied around me so Stuart could pull me out.  I'm convinced they're not there!

On a bright note, we now know it's not his ECU.

[LotuStuart]

16 minutes ago, Sparky said:

I went so far in, I needed a rope tied around me so Stuart could pull me out.  I'm convinced they're not there!

On a bright note, we now know it's not his ECU.

It was like a scene from Poltergeist.

 

[LotuStuart]

Found it. Cable tied behind the speaker. 

[Sparky]

Kinell!

[swindon_alan]

On the subject of OBD sockets, I have long been slightly mystified by the additional three wires on the rear (boot) connector. The front one doesn't have them? In the course of digging around on my Kelsey Hayes EBC work (and connections to the ECM)  I came across what I believe is the answer.

This is from a third party (non car model specific) EFI MT-501 document:

In the OBD2 spec these pins are listed as "manf. discretion/OEM reserved". Now, as the MT-501 natively supports CAN, I'm thinking that perhaps Lotus either implemented CAN or put the connections in for potential future use, as the later spec was an incoming preferred standard in 1996.

So as well as the the K-Line Protocol Numbers 4 and 5 on pin 72 that we all use with ELM 327 adapters there might be an alternative high speed interface. Another option might be that it was used to upload the V8 specific configuration into PROM.

Something to chew on. I might investigate further when Nelson gets his eye back. Anyway, mystery solved for now.

[sailorbob]

I suspect those three pins are for programming the ECU.

[swindon_alan]

I suspect that your suspicions are correct Derek:

The MT-501 has those pesky ST M29F010B 1Mbit EEPROMS in PLCCs that you have to remove, fit sockets and replace if you want to change the maps. Taking a cue from Esprit Engineering:

Now I know this (and we have a Write Enable line identified), I reckon there's a possibility of doing the reprogramming myself without opening the ECM up. This is the pin out from the EFI wiring loom that has multiple connectors for this, a dashboard and a data logger - all using CAN.

Easy enough to knock up an interface cable.

Also digging through the documentation and thinking about it, the K-Line and CAN data streams both use pin 72 on the ECM/pin 7 on the DLC connector. The CAN_H/CAN_L and WR EN are used to enable this (but again, only on the rear DLC connector).

I wonder if I can get hold of the original  MT-501 utility software, it comes on a "single high density floppy disk" apparently. Good job I still have a 3.5" FD USB drive..!

[sailorbob]

ECU access for programming will almost certainly be password protected.

[swindon_alan]

So it is also a good job that I have a password cracker then Derek! Assuming that it doesn't have much in the way of a defence (time outs/lock on fails etc.)

[Espritv8black]

Those 3 pins are in all OBDII sockets in all cars.  They are manufacturer or Mark specific so that when a manufacturer has specific technology that they don't want others to be able to see they access the data through these 3 pins.  All have these 3 pins, Ferrari, Lamborghini, Corvette etc.

[Project M71]

On 10/01/2020 at 14:05, swindon_alan said:

Hi swindon_alan,

Can you share the third party (non car model specific) EFI MT-501 document

 

 

I suspect that your suspicions are correct Derek:

The MT-501 has those pesky ST M29F010B 1Mbit EEPROMS in PLCCs that you have to remove, fit sockets and replace if you want to change the maps. Taking a cue from Esprit Engineering:

Now I know this (and we have a Write Enable line identified), I reckon there's a possibility of doing the reprogramming myself without opening the ECM up. This is the pin out from the EFI wiring loom that has multiple connectors for this, a dashboard and a data logger - all using CAN.

Easy enough to knock up an interface cable.

Also digging through the documentation and thinking about it, the K-Line and CAN data streams both use pin 72 on the ECM/pin 7 on the DLC connector. The CAN_H/CAN_L and WR EN are used to enable this (but again, only on the rear DLC connector).

I wonder if I can get hold of the original  MT-501 utility software, it comes on a "single high density floppy disk" apparently. Good job I still have a 3.5" FD USB drive..!

 

[Project M71]

I've got the Data Sheet for the AM29F010-70JC Flash chips and and I'm wondering if some of the issues with MT-501 ECUs that fail to reflash could be poor connections to pin 31 on the soldering on the sockets, as this is WE Write Enable line...
 

[Barrykearley]

From memory you can also lock those chips and make reflash impossible.

[Project M71]

This is possible with the device (quotes below from Data Sheet attached) but this wouldn't apply to new, blank chips...

 

Sector Protection/Unprotection
The hardware sector protection feature disables both
program and erase operations in any sector. The hardware
sector unprotection feature re-enables both
program and erase operations in previously protected
sectors.
Sector protection/unprotection must be implemented
using programming equipment. The procedure requires
a high voltage (VID) on address pin A9 and the
control pins. Details on this method are provided in a
supplement, publication number 22337. Contact an
AMD representative to obtain a copy of the appropriate
document.
The device is shipped with all sectors unprotected.
AMD offers the option of programming and protecting
sectors at its factory prior to shipping the device
through AMD’s ExpressFlash™ Service. Contact an
AMD representative for details.
It is possible to determine whether a sector is protected
or unprotected. See “Autoselect Mode” for details.

 

Hardware Data Protection
The command sequence requirement of unlock cycles
for programming or erasing provides data protection
against inadvertent writes (refer to the Command Definitions
table). In addition, the following hardware data
protection measures prevent accidental erasure or programming,
which might otherwise be caused by
spurious system level signals during VCC power-up and
power-down transitions, or from system noise.

RS_AM29F010-70JC.pdf

Edited November 18, 2021 by Project M71

[Project M71]

 

The MT-501 firmware does allow password protection of the two tables but again this wouldnt apply to a blank chip 

 

Edited November 18, 2021 by Project M71