Loss of power and gearbox/Parkbrake fault

**Romeo** · 17th October 2023, 10:27 PM

Hi, guys
I was driving MY17 Disco Sport HSELux at through the Hay plains on cruise control. Pulled out to pass a semi and suddenly Gear box Fault and Park Brake Fault messages start flashing, and engine immediately drops to idle with no response to accelerator. No funny noises. Coasted to roadside, no phone coverage, wondering what to do… Stop and restart engine - starts and idles fine, but no accelerator response, and fault messages on info display.

Cut long story short… after about 15 minutes, restart engine, and presto, all working ok, no error messages, except engine fault light is on. Move off, slowly at first, then without further ado get to Mildura that evening and back to Adelaide the next day without incident (except next day, the MIL light was out while engine was running, but still on when ignition on but engine not running).

Been meaning to get a GAP tool for a while, so did it, and saw two faults reported at the time of the incident, namely

ABS-Brake Module U0001-81 (28) HS CAN bus - signal/message failure - invalid serial data received, and
TCM - P0700-02 (28) Transmission control system (MIL request) - General failure info - general signal failure

Interestingly, the tool also reported a similar fault from a year ago which went totally undetected
PAM - Parking Aid
U100B-00 (68) Semi automatic parking system, and
U0001-82 (68) HS CAN bus - signal/message failure - alive/sequence counter is incorrect/not updated

I have since searched and read a lot about similar occurrences on a number of forums, but nothing conclusive.
I would appreciate opinions from those wiser than I about such things as to whether this is something to be concerned about, and if so, what should be my next step?

Roman

**Graeme** · 18th October 2023, 06:11 AM

That might be a hard one to track down as it suggests a HS canbus wiring fault, possibly a broken wire although I would expect faults to occur often if a broken wire, that in your latest event triggered the gearbox fault. My 2012 RR had an intermittent park brake fault in wet weather which was caused by a wire that had been rubbing had worn through the insulation allowing the wire to be grounded.

**DiscoDB** · 18th October 2023, 04:32 PM

Might be worthwhile checking if there is a TCM ECU update needed as there was a software problem with some 2017/2018 Range Rovers and Discoveries that could trigger the P0700-02 fault.

**101RRS** · 18th October 2023, 05:08 PM

Check engine light is supposed to be on with ignition on and engine not running - so are most of the other lights - is the check bulbs process of a start.

**Romeo** · 18th October 2023, 08:05 PM

Originally Posted by DiscoDB

Might be worthwhile checking if there is a TCM ECU update needed as there was a software problem with some 2017/2018 Range Rovers and Discoveries that could trigger the P0700-02 fault.

Thanks. I looked at Topix just the other day and it said that there were no “campaigns” outstanding on this car. Is that what you mean by checking?

Roman

**Romeo** · 18th October 2023, 10:04 PM

Originally Posted by 101RRS

Check engine light is supposed to be on with ignition on and engine not running - so are most of the other lights - is the check bulbs process of a start.

Thanks 101RRS,
Yes, the dash lights up like a Christmas tree, but most of them go out after a couple of seconds. MIL light is the only one that stays on that “doesn’t belong”.
Roman

**DiscoDB** · 18th October 2023, 10:12 PM

Originally Posted by Romeo

Thanks. I looked at Topix just the other day and it said that there were no “campaigns” outstanding on this car. Is that what you mean by checking?

Roman

The normal advice is to not update any ECU unless you have a specific problem that can’t be fixed. So I would only consider this if you continue to have a problem and can’t find any other reason for it.

If the car is still being serviced by LR you can report the problem and ask them if there is an ECU update available for the TCM.

If you are no longer going back to LR, then you can also enquire via Gap-Diagnostics if an update for the TCM is available. They also have a “fast track” service option to supply updates.

The following technical bulletin refers to a specific problem in the US, but have also read it in a different place which also referenced 2017 models. Also affected some Jaguars.

https://static.nhtsa.gov/odi/tsbs/20...45635-9999.pdf

Note: not saying this is the problem either, but coincidental that some 2017/2018 JLR vehicles had a potential TCM software problem that could generate the same fault code and just needed a software update.

**Romeo** · 19th October 2023, 10:12 PM

Originally Posted by DiscoDB

If you are no longer going back to LR, then you can also enquire via Gap-Diagnostics if an update for the TCM is available. They also have a “fast track” service option to supply updates.

The following technical bulletin refers to a specific problem in the US, but have also read it in a different place which also referenced 2017 models. Also affected some Jaguars.

https://static.nhtsa.gov/odi/tsbs/20...45635-9999.pdf

Thanks, DiscoDB
I will ask the question of Gap, but I note your caution about updates unless you know it’s a problem. I will also ask the local dealer, although the car’s no longer under service contract or warranty so not sure where this will go. At the moment, I’m still thinking CAN bus hiccup.

And thanks also for the Service Bulletin. The wealth of knowledge and resource on this board never ceases to amaze.
But what is a an “Auto Stop/Start Event” exactly? Is that what happened to me?

Edit: Oops..In my mind I didn’t connect the Auto Stop/start Event referred to in the bulletin with the common stop/start function when stopping at the lights. I saw “Auto” and assumed it was something to do with the auto transmission. What the heck has that to do with a transmission fault? Hmm. Late night!

Roman

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