ABS sensor fault and diagnostics

[davo]

So I just came back from a big trip to Cape York.
The Grenadier performed great - although annoyances with AC/TPMS/Diff lock continued.

One interesting thing which happened was a stick getting flicked up behind a harness which connects to the rear diff lock and the rear left ABS sensor - breaking some wires and ripping some out of a connector. That resulted in the errors shown in the photos shown on the cluster and centre screen.

So there was an ABS fault - then a whole bunch or other errors. My understanding is that there is the ABS error (which is understandable given one wheel speed sensor is no longer connected) - then all the other errors are secondary due to the other modules no longer receiving an accurate vehicle speed signal from the ABS module (so the Trailer stability / downhill assist / uphill assist / power steering / engine and transmission faults). As an ex powertrain diagnostics engineer I was pretty disappointed to NOT see a message just saying something like "rear left wheel speed sensor open circuit". So no message which actually indicated the root cause of the problem. Apparently there was a code saying that on the ABS module but it does not get shown on the centre screen.

On calling Ineos support (and being 1000km from the nearest dealer) they said "are there any warning in RED? no? then keep driving!". Faced with a big wait for a tray truck or a long drive with no ABS I chose to drive. It was interesting to note that if you then locked up the brakes (was driving on lots of poor dirt roads) then the transmission module would flag a red error and go into limp home (seemed to be stuck in 3rd gear). That reset itself if you stopped the car and waited 20 minutes.

The issue was solved for me by driving a few days with no ABS to Wesco Ineos Cairns - who quickly diagnosed and repaired the harness.

When you are sitting in your Grenadier in 1000km from anywhere with the transmission stuck in 3rd gear and waiting 10mins with the key off for the error to clear - it really make to realise it would be good to have an OBD tool for this vehilce! As I understand it the ABS module is hidden behing the gateway module and so only Ineos tools can see diagnostic codes / DTCs on the module.

Come on Ineos - repair manual and OBD tool - get on with it - the owners need them!

 

[[ Adam ]]

I've had my Grenadier go into limp mode exactly twice. Both times, I was able to clear the code using a generic OBD2 reader. I agree 100% that long term, we need tooling to allow us to clear codes beyond the generics.

 

[Jean Mercier]

I agree completely with your comments about the OBD tool and access to other information (repair manual). They promised things like that before launching the car and I am owner since more than 2 years and the promises aren't kept.

By the way, your car has a very nice color

 

[davo]

I've had my Grenadier go into limp mode exactly twice. Both times, I was able to clear the code using a generic OBD2 reader. I agree 100% that long term, we need tooling to allow us to clear codes beyond the generics.

yeah - as I understand it according to OBD legislation you have to be able to read and clear codes related to engine emissions issues but not necessarily other vehicle problems. So mostly codes on the engine (and maybe transmission modules and exhaust aftertreatment / adblue dosing modules). The main issue I have is that you can't read or clear codes on any of the other modules with the standard OBD code reader - so there was no way to diagnose which wheel speed sensor was causing the problem because you cant see the ABS module. So pretty sure in my case I could have seen an engine module code (saying there was a bad speed signal from the ABS module) if I did have a standard OBD code reader with me - but it wouldnt have helped much.

 

[ADVAW8S]

What about the ability to use diff locks? Did the stick effect the speed sensor for diff locks?

 

[davo]

What about the ability to use diff locks? Did the stick effect the speed sensor for diff locks?

so the same harness connects to the rear diff lock and left rear ABS sensor. Wires were ripped from the rear diff lock solenoid connector - that that didnt work either.

 

[[ Adam ]]

yeah - as I understand it according to OBD legislation you have to be able to read and clear codes related to engine emissions issues but not necessarily other vehicle problems. So mostly codes on the engine (and maybe transmission modules and exhaust aftertreatment / adblue dosing modules). The main issue I have is that you can't read or clear codes on any of the other modules with the standard OBD code reader - so there was no way to diagnose which wheel speed sensor was causing the problem because you cant see the ABS module. So pretty sure in my case I could have seen an engine module code (saying there was a bad speed signal from the ABS module) if I did have a standard OBD code reader with me - but it wouldnt have helped much.

we agree