95 Disco resetting reading SRS(airbag codes)

FatMcNasty

Well-known member
Mar 28, 2006
204
63
Southern Oregon
Hey all, It finally time for me to give back to the Land Rover forum help world.
I've been fighting with a SRS light on the dash for a number of years and FINALLY got around to fixing it. And I'm going to pass this on to all the poor souls that are stuck with a pre ODBII system.
Tools needed. Hawkeye Total reader, and BA5077 adapter for Airbags. Your thinking WTF Fat! I cant plug this in to my system I don't have a ODBII port!
Well we are going to make ONE! So grab a ODBII plug with pig tail from Amazon or some one else. Next find a plug that will work with the Airbag Diagnostic port. Its a square 4 pin plug look under your dash and it might still have one attached. If not get a scrap Ignition lock and pull it off of that one.
Pin out is as follows. pin 16 is 12V put a 2 amp fuse on it just incase.
Pin 4 goes to ground on the body.
Pin 14 goes to the upper left of the 4 pin to Yellow Pink
Pin 13 goes to the upper right pin Yellow Green
Pin 5 goes to lower left.

20200609_140153_13c21baf0647a720b55125008dfd286813f80456.jpg


20200613_173301_07b324e5848709e3440fbc5d38b70affbfd2f5ae.jpg


Like so.. Here is a shot of the whole adapter.

20200613_173254_f275627c94e2888baf709dc1d709743ebf67799c.jpg

Once done making the cable, attach it in the rover, You can get power for it from the fuse box spade port 1, this gives power when the system is keyed on.
Attach the BA5077 adapter, which is just a pin shifter, that moves the reading pins from 15 and 7 to 13 and 14, which is the layout on the 96 forward DI's.
Attach the Hawkeye turn on ignition and read the DTC's then clear them. You will need to select the TRW MPS version. Mine was reporting a mem error and that what flagged it on for all these years.

So I hope this helps out another owner with the 95 system, I see there are a few of us out there with SRS lights on. And now finally a way to fix it with out having to go to the dealership to hook up the testbook to it.

Cheers
FatMcNasty
 

FatMcNasty

Well-known member
Mar 28, 2006
204
63
Southern Oregon
You are welcome, I've been trying to find a fix for years. Lots of oh just hook it up to the odb port and reset it. And you cant do it with out the Factory testbook. Next on my list is the ABS system, so i can power bleed the breaks. And Ill have version 2 of the harness that will use the Nanocom leads for a more simpler user friendly experience (so a ODBII to 15 pin D female connector). since the prebuilt leads for the nano are not too expensive.
 

strat440

Active member
Mar 18, 2011
30
2
Northern Virginia
You are welcome, I've been trying to find a fix for years. Lots of oh just hook it up to the odb port and reset it. And you cant do it with out the Factory testbook. Next on my list is the ABS system, so i can power bleed the breaks. And Ill have version 2 of the harness that will use the Nanocom leads for a more simpler user friendly experience (so a ODBII to 15 pin D female connector). since the prebuilt leads for the nano are not too expensive.
You wrote that the BA5077 dongle is just a pin-shifter. Do you think there is a way to recreate the dongle? They're hard to find these days.
 

strat440

Active member
Mar 18, 2011
30
2
Northern Virginia
Actually, I notice you wrote in your original post that the BA 5077 adapter shifts 15 to 13 and 7 to 14. So, if I were to get separate male and female OBDII connectors off Amazon (each ending in wires), and then connected those four wires in that specific way, would that effectively recreate the BA 5077 adapter?
 

FatMcNasty

Well-known member
Mar 28, 2006
204
63
Southern Oregon
yes, sorry I got busy last night. I've got 2 major software upgrades I'm pushing out at where I work. So its been is bit crazy. its like 2-3 pins shifted ground and power and second ground are passed through. Ill verify it when I can. but a male and female ODB2 connector is what you seek.
 
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Reactions: strat440

strat440

Active member
Mar 18, 2011
30
2
Northern Virginia
Hey all, It finally time for me to give back to the Land Rover forum help world.
I've been fighting with a SRS light on the dash for a number of years and FINALLY got around to fixing it. And I'm going to pass this on to all the poor souls that are stuck with a pre ODBII system.
Tools needed. Hawkeye Total reader, and BA5077 adapter for Airbags. Your thinking WTF Fat! I cant plug this in to my system I don't have a ODBII port!
Well we are going to make ONE! So grab a ODBII plug with pig tail from Amazon or some one else. Next find a plug that will work with the Airbag Diagnostic port. Its a square 4 pin plug look under your dash and it might still have one attached. If not get a scrap Ignition lock and pull it off of that one.
Pin out is as follows. pin 16 is 12V put a 2 amp fuse on it just incase.
Pin 4 goes to ground on the body.
Pin 14 goes to the upper left of the 4 pin to Yellow Pink
Pin 13 goes to the upper right pin Yellow Green
Pin 5 goes to lower left.

20200609_140153_13c21baf0647a720b55125008dfd286813f80456.jpg


20200613_173301_07b324e5848709e3440fbc5d38b70affbfd2f5ae.jpg


Like so.. Here is a shot of the whole adapter.

20200613_173254_f275627c94e2888baf709dc1d709743ebf67799c.jpg

Once done making the cable, attach it in the rover, You can get power for it from the fuse box spade port 1, this gives power when the system is keyed on.
Attach the BA5077 adapter, which is just a pin shifter, that moves the reading pins from 15 and 7 to 13 and 14, which is the layout on the 96 forward DI's.
Attach the Hawkeye turn on ignition and read the DTC's then clear them. You will need to select the TRW MPS version. Mine was reporting a mem error and that what flagged it on for all these years.

So I hope this helps out another owner with the 95 system, I see there are a few of us out there with SRS lights on. And now finally a way to fix it with out having to go to the dealership to hook up the testbook to it.

Cheers
FatMcNasty
Quick question: for power, are you saying take pin 16 from the input, put a 2amp fuse on the wire, then end it in a clip to go on the fuse box? And, then, just find a spot on the chassis to attach the ground?

I was also thinking, would it be possible to actually recreate a full OBD2 for the Hawkeye by connecting all three ports to an OBD2 plug: this srs port, the blue ABS port, and the 14cux port? Then there would just be one spot to attach for every purpose. Would just need to know the pins for the SRS dongle and 14cux.
 

robertf

Well-known member
Jan 22, 2006
4,780
354
-
Is there any resistance between 4 or 5 to let the reader know which dongle is plugged in?
 

FatMcNasty

Well-known member
Mar 28, 2006
204
63
Southern Oregon
Quick question: for power, are you saying take pin 16 from the input, put a 2amp fuse on the wire, then end it in a clip to go on the fuse box? And, then, just find a spot on the chassis to attach the ground?

I was also thinking, would it be possible to actually recreate a full OBD2 for the Hawkeye by connecting all three ports to an OBD2 plug: this srs port, the blue ABS port, and the 14cux port? Then there would just be one spot to attach for every purpose. Would just need to know the pins for the SRS dongle and 14cux.

I actually thought about doing that. if you have the RAVE manual use the 96 export wiring diagram. That's what I used to backwards engineer the cables needed.
 

strat440

Active member
Mar 18, 2011
30
2
Northern Virginia
I actually thought about doing that. if you have the RAVE manual use the 96 export wiring diagram. That's what I used to backwards engineer the cables needed.
Well, I finally got everything I needed, and it worked like a charm! Even without the 5077 dongle; I just directly wired it to the shifted pins. Thank you so much!
 
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Reactions: FatMcNasty

Toran

Well-known member
Feb 3, 2017
416
48
Ohio
Hey strat440,

Congrats on getting your SRS light off.

I have a Hawkeye scantool and was wondering if you could walk me through the exact steps for creating this $100.00 BA5077 dongle to turn off / reset my SRS light.

The SRS light came on when I replaced the battery a few months ago. Any additional insight would be much appreciated.
 

Toran

Well-known member
Feb 3, 2017
416
48
Ohio
Hello again,

Since I have an OBD2 port would I be looking at something like this to create a fake BA5077 dongle to work with my HawkEye?

Thanks
 

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strat440

Active member
Mar 18, 2011
30
2
Northern Virginia
Hey strat440,

Congrats on getting your SRS light off.

I have a Hawkeye scantool and was wondering if you could walk me through the exact steps for creating this $100.00 BA5077 dongle to turn off / reset my SRS light.

The SRS light came on when I replaced the battery a few months ago. Any additional insight would be much appreciated.
Sorry I didn't respond, I haven't logged in in awhile. Do you have a hawkeye-to-obd2 cable and just need to recreate the dongle, or do you not have either a cable or dongle?
 

Toran

Well-known member
Feb 3, 2017
416
48
Ohio
Hey strat440,

I only have the Hawkeye and the cable that came with it.

Thanks
 

strat440

Active member
Mar 18, 2011
30
2
Northern Virginia
Hey strat440,

I only have the Hawkeye and the cable that came with it.

Thanks
I think that should end in a male OBD2 plug? And you said your disco has an OBD2 port, which should make things easier. It means you only need to recreate the dongle.

The OBD2 plug has 16 pins. As FatMcNasty explains, the dongle simply shifts certain pins in the following way:

In - Out
4 - 4
5 - 5
7 - 13
15 - 14
16 - 16

"In" means the pins on the Hawkeye plug (which connects to one side of the dongle) and "Out" means the pins on the end of the dongle that plugs into the Disco port. You can look up OBD2 pinout on Google to see which pin is in which spot on the plugs

When you plug the Hawkeye cable straight into the Disco's OBD2 port, everything lines up as intended. The first pin in the plug connects to the first pin in the port, and so on. Apparently, from what FatMcNasty writes, the SRS reset function only uses 6 of those 16 pins. But for whatever reason, resetting the SRS needs the 7 pin on the Hawkeye plug to connect with the 13 pin on the port on the Disco, and the 15 pin on the plug with the 14 pin on the port. What the dongle does is connect all the other pins straight through, while using wires inside to make those 2 shifted connections.

There may be a better way, but what I would do is just get a male to female OBD2 cord and cut it in half (alternatively, you could buy a pigtail male OBD2 cord and a pigtail female OBD2 cord, which gives you the same thing). The Hawkeye cable will plug into one of the halfs, and the other half will plug into the Disco. In between, you just manually solder the wires as needed.

To do that, strip back the main insulation an inch on each half and separate out the 16 wires (unless you bought the 2 pigtails, which come that way). You can tell which wire goes to which pin with a multimeter; put one probe on the pin (or shove it in the pin socket on the female side) and touch each of the 16 wires until it registers on the multimeter. When you find the wires for 4, 5, 7, 15, and 16 on the side that will connect to the Hawkeye cable (should be the female plug), put a little tape flag on the wire and write the number on it. Do the same for the 4, 15, 13, 14, and 16 on the cable that will connect to the port on the Disco (should be a male plug). Then, solder them together in the pattern shown above, with 4, 5, and 16 going directly to the same number, 7 in soldered to 13 out, and 15 in soldered to 14 out. Use a heatshrink or some other method to insulate, and all other proper precautions. Fat McNasty recommended soldering a 2 amp fuse between the 16 wires, which I did for added safety in case something was messed up. I don't think you need to bother soldering any of the other pins wires together, but I don't know for sure. I don't see why you would need to, I only needed the 6 wires for mine.

I must note that I am neither an electrician nor an expert at this. I just followed FatMcNasty's instructions and it worked for me, and this is just my attempt at applying the same instructions as applied to the OBD2 port on your car instead of the port on my '95. Your mileage may vary, and I could've made a mistake, so proceed with caution.