Disco 3 (LR3) Steering Angle Readings....Curious!

sierrafery said:

IMO that generic fault code is not enough to get to the root of that fault cos the C0198 has 9 subcodes, the 0197 has 8 some of them directly related with the orientation or instalation of the sensors, IMO you'll have to use a more reliable tool to diagnose this and follow the exact procedures from the WSM cos these vehicles are very sensitive in this area, see the document https://docdro.id/sD144vV

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Thanks for the document link - I have indeed read this one already - as can be seen in the video - I have run a new wiring pair form the sensor up to the ABS module and it still gives incorrect values on both the old Yaw sensor and the new one! And similarly if I swap the ABS module - it is the exact same live data readings and same fault codes regardless.

So if it is a new sensor, new wiring and even a replacement ABS module - how can it be that the same faults and same live data readings are being reported? The sensor talks with the ABS Module via a direct hard wired link and not via the CAN so it can't be disruption on the CAN causing the incorrect values and there is nothing in between the sensor and the ABS module that can cause incorrect values to be delivered - it does go via the CJB in normal operation - but I bypassed that by using all new wiring direct to the ABS module!

Stumped at the moment, the wife has the car with her today, but when see gets back I may scope the output from the sensor itself and see what that comes up with!

IMO you should do somehow and find somebody with a proper diagnostic tool to read the exact fault code cos some subcodes for the C1A98 are blaming the SA sensor, anyway, good luck, i feel your pain

sierrafery said:

IMO you should do somehow and find somebody with a proper diagnostic tool to read the exact fault code cos some subcodes for the C1A98 are blaming the SA sensor, anyway, good luck, i feel your pain

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I feel my pain too....lol....

Thanks for the input, I will crack on and see what I can further find out.

Such fun!

Wow ant its really putting you threw the grinder !

biketeacherdave said:

Wow ant its really putting you threw the grinder !

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This one really is Dave - it is because I can't see what could be wrong considering I have tried replacement sensor and a replacement ABS module AND replacement wiring...so I can't fathom what could be wrong.

As mentioned above, it could be the Steering Angle Sensor ruining the party - so I will look into that one...

When you get the car for free you do have to take the rough with the smooth!

Omg mate , indeed can relate with being there in having to rip a lot out with errors

indeed with regards to what @sierrafery has said with regards to diagnostics , in getting a more powerful scan reader on the disco

have u also checked the connector at the back left rear wheel plse , personally would fit a new steering wheel angle sensor , but that’s just my own personal choice and no guarantees of it working , just thoughts

Shame ur not closer as I have a gap iid and an Autel mx808 and would have happily plugged that in for u

know when I’ve had wiring issues before it can be a living nightmare trying to pin errors down and really hope u can get a better scanner on there

also whilst having the canbus laptop running have u gone round wiggling connectors to see if anything changes at all

another thing is to ask on the D3 forum in case someone is near u that has an gap iid or better to plug it in for u , know there are several on there who are also knowledgeable

plse let us know how u get on and following with interest

Hope u don’t mind me adding one last thing that I learnt, plse walk away from it for a few days otherwise u will drive urself nuts

biketeacherdave said:

Wow ant its really putting you threw the grinder !

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seeing this reminds me when I had to try and find the cabins airbag issue out , drove me nuts , got caught out a few times testing continuity with a multimeter where it would pass but failed with a test light as indeed wasn’t putting the wires under load

indeed can be like going down a rabbit hole

Plus have u ever done this ref a yaw rate sensor recalibration , believe it can take 2-3 times to work with a new one , know it’s clutching at straws but wished to at least share the info just in case


- Find a free piece of road.
- stop the car and turn off ignition.( gear in P )
- start engine
- put the car in low range ( makes it easier, less speed and distance )
- then drive the car, allowing all the gears to got through ( up to 5 )
- stop
- put the car in reverse
- drive 100 or so meters in reverse.
- stop
- switch every thing off
- take the key out
- wait a couple of minutes.
- restart the car

this is the end of the recalibration

So a few weeks ago I ran new wiring from the Yaw Rate Sensor up to the ABS module:



But that didn't change a thing, it still reported a circuit fault on both the Yaw and Laterl readings....

Also, the actual Live Data figures for the Yaw and Lateral didn't budge!!

So, I have proved power and ground are good, I have run new wires direct to the ABS module, i have changed the Sensor for a replacement, I have changed the ABS module for a replacement and it still reports the same faults and the same live data readings....

On suggestion, this weekend I changed the Steering Angle Sensor and recalibrated and that did nothing either!!

Another suggestion was to drive it in Low Range in every gear and then reverse for a 100yds or so, and it may take a couple of goes as this apparently may reset the Yaw Sensor - but this also has had no effect.

I have scoped the CANBus and that seems to be talking OK - although curiously when you turn the ignition off, the CAN signal changes as if the CAN is shorted to ground as per my video here:



Not sure if that is correct behaviour as on my BMW when you turn the ignition off and the CAN goes to sleep the voltage flatlines. I will need to see if I can find someone local with a D3 how is willing to let me scope their CAN and find out!

I am running out of ideas now - as per the other posts above, I have checked and cleaned the TCM connections and also opened it up and all looks good.

I am at a loss as to what the cause is - anyone ave any further ideas on what can be checked?

Wow ant I think you have pretty much done everything. Where abouts are you again ? Iv no problem you scoping our D3 if it helps

gstuart said:

Many thks for the results

everything looks fine apart from the last ones 14/4 and 14/5 as should read around 2.4 - 2.5 Vdc

enclosed a picture for u, which shows 14 is ur can low and 4 chassis ground / the other 5 is ur signal ground

therefore I’m wondering if u have a bad earth, various places of the earths are , behind ur drivers side wheel arch liner , behind the drivers side headlight and behind the passenger side wheel arch liner

know the other guys here being @biketeacherdave and @lynall are vastly more knowledgeable than myself so maybe they know exactly where to go



View attachment 283435

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@Saint.V8

just gone back and this is really the only thing I’ve found with regards to the low Vdc on the 14-4 canbus

also just trying to double check for u when u replace an ABS module if it requires re programming , alas haven’t found out 100% if that’s the case

will see if I can find out any more info for u as indeed always a team effort , see you’ve posted over in the D3 forum so hopefully someone else over there may know

ref the canbus after the ign has been turned off, enclosed the sheet for u with regards to how long it takes to shut down

really feel for u mate and hopefully we can find out what the hell is going wrong

gstuart said:

@Saint.V8

just gone back and this is really the only thing I’ve found with regards to the low Vdc on the 14-4 canbus

also just trying to double check for u when u replace an ABS module if it requires re programming , alas haven’t found out 100% if that’s the case

will see if I can find out any more info for u as indeed always a team effort , see you’ve posted over in the D3 forum so hopefully someone else over there may know

ref the canbus after the ign has been turned off, enclosed the sheet for u with regards to how long it takes to shut down

really feel for u mate and hopefully we can find out what the hell is going wrong

View attachment 287382

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Thanks for the info above- a font of knowledge you are!!

The waveform on the CAN goes immediately to short to ground when you turn the ignition off, which I am not 100% sure is correct as I am sure (and as listed above) there should be a period of time before the CAN sleeps - and when the CAN sleeps on the BMW it goes flatline, whereas on the D3 if shorts itself to ground as soon as you turn the ignition off - this is shown by the fact the CAN High Signal carries on but the CAN Low Signal is immediately pulling down to 0V - whereas the 'off' state is 2.4-2.5V....this is shown in this video from MechanicMindset at 4m10s:



I am sure it should not short to ground on ignition off....

Anyhow: I did get it on Autologic to pull the exact 7 digit code for the Yaw and Lateral faults:

C1A197-86 - Lateral Accelerometer Circuit - Signal is Invalid
C1A198-01 - Yaw Rate Sensor Circuit - General Electrical Failure
C1A198-86 - Yaw Rate Sensor Circuit - Signal is Invalid

From the reference document @sierrafery posted above this could be:

C1A97-86
Lateral Accelerometer -Signal invalid
Signal invalid
..Signal circuit high resistance
..Signal circuit short circuit to ground
..Signal circuit short circuit to power
Yaw rate/lateral acceleration sensor internal error
Check the combined lateral acceleration/yaw
rate sensor installation. Refer to the electrical
guides and check the yaw rate sensor circuit.
Repair/renew as necessary. Refer to the
relevant section of the workshop manual. Refer
to the guided diagnostic routine for this code
on the approved diagnostic system.

C1A98-01 Yaw Rate Sensor - General electrical failure
General electrical failure
..Reference circuit high resistance (DRSR pin)
..Reference circuit short circuit to ground (DRSR pin)
..Reference circuit short circuit to power (DRSR pin)
Yaw rate/lateral acceleration sensor internal error
Check the combined lateral acceleration/yaw
rate sensor installation. Refer to the electrical
guides and check the yaw rate sensor circuit.
Repair/renew as necessary. Refer to the
relevant section of the workshop manual. Refer
to the guided diagnostic routine for this code
on the approved diagnostic system.

C1A98-86 Yaw Rate Sensor - Signal invalid
Signal invalid
..Signal circuit high resistance (DRSS pin)
..Signal circuit short circuit to ground (DRSS pin)
..Signal circuit short circuit to power (DRSS pin)
Yaw rate/lateral acceleration sensor internal error
Check the combined lateral acceleration/yaw
rate sensor installation. Refer to the electrical
guides and check the yaw rate sensor circuit.
Repair/renew as necessary. Refer to the
relevant section of the workshop manual. Refer
to the guided diagnostic routine for this code
on the approved diagnostic system.

So it could be a bad reference voltage to the sensor. I pulled fuse 37 (5amp) which provides voltage to the sensor and also to the ABS module and it is fine, measured the voltage at the fuse and that is spot on with battery voltage.

What I am planning to do next is to give it a direct connection to the battery bypassing fuse 37 and seeing if it could be a dodgy power feed to the sensor giving spurious readings - as one of the fault causes for C1A98-01 is poor quality reference voltage.

I tried to eliminate the Signal Circuit issues by using a new wired connection to the ABS module as shown in the video, but still had the same faults....so I wonder if it could be poor quality reference voltage feeding the sensor - its worth a shot!

Saint.V8 said:

Thanks for the info above- a font of knowledge you are!!

The waveform on the CAN goes immediately to short to ground when you turn the ignition off, which I am not 100% sure is correct as I am sure (and as listed above) there should be a period of time before the CAN sleeps - and when the CAN sleeps on the BMW it goes flatline, whereas on the D3 if shorts itself to ground as soon as you turn the ignition off - this is shown by the fact the CAN High Signal carries on but the CAN Low Signal is immediately pulling down to 0V - whereas the 'off' state is 2.4-2.5V....this is shown in this video from MechanicMindset at 4m10s:



I am sure it should not short to ground on ignition off....

Anyhow: I did get it on Autologic to pull the exact 7 digit code for the Yaw and Lateral faults:

C1A197-86 - Lateral Accelerometer Circuit - Signal is Invalid
C1A198-01 - Yaw Rate Sensor Circuit - General Electrical Failure
C1A198-86 - Yaw Rate Sensor Circuit - Signal is Invalid

From the reference document @sierrafery posted above this could be:

C1A97-86
Lateral Accelerometer -Signal invalid
Signal invalid
..Signal circuit high resistance
..Signal circuit short circuit to ground
..Signal circuit short circuit to power
Yaw rate/lateral acceleration sensor internal error
Check the combined lateral acceleration/yaw
rate sensor installation. Refer to the electrical
guides and check the yaw rate sensor circuit.
Repair/renew as necessary. Refer to the
relevant section of the workshop manual. Refer
to the guided diagnostic routine for this code
on the approved diagnostic system.

C1A98-01 Yaw Rate Sensor - General electrical failure
General electrical failure
..Reference circuit high resistance (DRSR pin)
..Reference circuit short circuit to ground (DRSR pin)
..Reference circuit short circuit to power (DRSR pin)
Yaw rate/lateral acceleration sensor internal error
Check the combined lateral acceleration/yaw
rate sensor installation. Refer to the electrical
guides and check the yaw rate sensor circuit.
Repair/renew as necessary. Refer to the
relevant section of the workshop manual. Refer
to the guided diagnostic routine for this code
on the approved diagnostic system.

C1A98-86 Yaw Rate Sensor - Signal invalid
Signal invalid
..Signal circuit high resistance (DRSS pin)
..Signal circuit short circuit to ground (DRSS pin)
..Signal circuit short circuit to power (DRSS pin)
Yaw rate/lateral acceleration sensor internal error
Check the combined lateral acceleration/yaw
rate sensor installation. Refer to the electrical
guides and check the yaw rate sensor circuit.
Repair/renew as necessary. Refer to the
relevant section of the workshop manual. Refer
to the guided diagnostic routine for this code
on the approved diagnostic system.

So it could be a bad reference voltage to the sensor. I pulled fuse 37 (5amp) which provides voltage to the sensor and also to the ABS module and it is fine, measured the voltage at the fuse and that is spot on with battery voltage.

What I am planning to do next is to give it a direct connection to the battery bypassing fuse 37 and seeing if it could be a dodgy power feed to the sensor giving spurious readings - as one of the fault causes for C1A98-01 is poor quality reference voltage.

I tried to eliminate the Signal Circuit issues by using a new wired connection to the ABS module as shown in the video, but still had the same faults....so I wonder if it could be poor quality reference voltage feeding the sensor - its worth a shot!

Click to expand...

Ur so welcome mate , have been going through a lot of the info , I’ll send u over a full yaw angle test sequence , alas can’t post it on an open forum because of copyright ,

apologises but you’ve already checked all the connection behind the drivers side footwell panel haven’t u including all the earths there , also just double checking what ones they are EDIT , sorry as see I posted it ref number 13 post

must confess I keep thinking it’s a bad ground , hopefully it’s something simple, did get caught out once on some earths before where it checked ur using a multimeter but then failed when I used a decent test light , of course know ur also very knowledgeable, it’s just passing comments and not wishing to try and teach u how to suck eggs

plse let me know if the test sequence is useful to u

Found these which should be ok to post here , am also double checking where the connectors are

Cheers bud - I did a temporary replacement of the Yellow/Brown and the Yellow/Black wires as shown in the video to take any issues with those wires out of the equation - same faults and same Live Data readings.

Next I intend to do a direct connection to battery (which is the Light Green wire) which will eliminate issues there could be with the two inline connections (C2243R and C0583R) and also takes the Splice Joint out of the equation too.....

Will also give it a fresh ground - just incase!!

Saint.V8 said:

Cheers bud - I did a temporary replacement of the Yellow/Brown and the Yellow/Black wires as shown in the video to take any issues with those wires out of the equation - same faults and same Live Data readings.

Next I intend to do a direct connection to battery (which is the Light Green wire) which will eliminate issues there could be with the two inline connections (C2243R and C0583R) and also takes the Splice Joint out of the equation too.....

Will also give it a fresh ground - just incase!!

Click to expand...

apologises mate as missed that ref wiring

funny enough just found that 583 connection, lol

indeed that’s a good call ref an earth , suppose easier and best coming off the battery neg post, at least then u know for sure it’s 100% sound , another one if theres earth issues is using a jump lead going from the battery neg post to the engine block , the lifting bracket is very good, alas might have to scrape some paint off to get a good key , easy to find with a multimeter

also going to sound daft but did u check that large rear near side connector that sits by the rear wheel plse , alas have to normally Remove the tyre for better access

plus when I was testing my ground I ran a long lead from the battery neg post and then used a test light for the interior testing for the 5vdc reference voltages as wished to put them under a load and not just belling them out with a multimeter

thinking aloud so to speak I assume the modules are ok seeing u can communicate with all of them, as first thought about seeing if u can communicate with them one by one to prove the 5vdc ref point is at each one , but don’t think it’s test the ground to each one, ie for the yaw sensor modules earth point

Turn the ignition on, Measure the voltage between the grounding point and the negative battery terminal. Is it less than 0.2 V

there’s also that very big ground wire behind the drivers side front wheel arch liner , will try and find a picture for u as I’m wondering if the ABS module uses that, know the starter motor does seeing it’s the same size as the ones by the battery

as always hope that none of this comes across trying to teach u how to suck eggs my friend , just trying to think of everything that could possibly be the issue, am still going through other lists etc that I’ve got

fingers crossed for u mate

Pictures of those earths points, some are behind ur drivers side headlight , down by the air box , also others by the drivers wing on the inside of the engine bay that’s tucked away near the A pillar , by the Volvo speaker , , along with that other one behind the drivers front wheel arch liner

can of course use the same test for any earths that ur unsure of , ref,


Turn the ignition on. Measure the voltage between the grounding point and the negative battery terminal. Is it less than 0.2 V?