Hi Guys
Can any one help I'm trying to find out what/where is the Rear differential control unit ?

Steve

I have the fault U0437 . It is permanent fault if I clear all codes and turn on ignition it returns without driving. (and only this code) The terrain response control module does not like the Rear diff control module. Trying to find this component just shows me the rear final drive complete unit. Been looking though the search not found any thing. Realise I'm being thick.
Hope someone can help.
Steve

Last edited by Steveja on 30th Oct 2021 2:14 pm. Edited 1 time in total

Hi Steve
The rear diff is entirely mechanical - there are no electronics in it. It is a simple differential unit. There is no "Rear differential control unit".

However I wonder if you are getting confused with the Haldex unit - an electronic drive shaft multi-plate clutch that bolts onto the front of the rear differential.
JLR refer to the Haldex as a "on-demand coupling"

Do you have the free JLR workshop manual - if not just search for it on here. Jules

Thanks Jules

Your right the text for code U0437 is missing me completely. Can you help told you I was thick. help

Steve

CODE U0437

The Terrain Response
Control Module has
detected that the Rear
Differential Control
Module component had
operated in a way or at
a time that it had not
been commanded to
operate[/img]

Found this
https://www.freel2.com/forum/topic27681.html


Also: as FL2 prone to generating error codes if battery is old, I would check the battery condition, check the battery earths, do a hard reset and then investigate further.
I'd go under the car and check the connection at the Haldex module and the wires for damage.

If you can supply more info when when asking for help, eg mileage, any other symptoms/signs of problems , what servicing has been done etc it gives people a better chance of offering useful advice
Regarding servicing, the recommended JLR servicing interval for the Haldex unit is generally considered inadequate and out of step with other car manufactures that also use these units.

Bell Engineering are the "go to" people regarding FL2 Haldex units.

There are others on here who can help with error codes more than myself. It should be noted that the error codes actually have extra 2 digits (DTC sub-codes) which can give more precise info but these cannot be read by cheapo OBD2 apps like Torque Pro. Jules

I'd be checking the Haldex fuse (FB6), in the rear fuse box. Hyundai Ioniq 5 Ultimate. The family car.
2009 Rimini Red SE TD4. Gone.
2006 Tonga Green i6 HSE. Gone.
Audi A5 convertible, my daily driver.
1972 Hillman Avenger GT, the project.

My Foxwell scanner has now packed up (just 2 years old) have borrowed a snap on scanner, reads 5 digits only.
Have checked the wiring best I can. I must admit I cant understand what U0437 trying to tell me. I note there is a company who will test the Haldex control unit if I post it to them.

Code U0437
TRCModule is unhappy with rear differential control module.

I have been scratching my head for days trying to decipher what this means in English. I note there is history on the site of this code but never any clues to its meaning. Considering that the rear diff is just a pretty ordinary open diff |I would suggest there is nothing to see there.

When you remove the TRCM it reveals 2 electrical components 1. The oil pres & temp sensor and 2. The clutch control valve I am suggesting this is AKA the elusive Diff control module.
I would be very interested any info / comments on this.

Steve

I thought I'd check in the JLR manual, what and where these modules are.
The TRCM is the rotary knob assembly between the front seats (in my car its a panel of press buttons).


The "Electronic rear differential control module" is what most people refer to as the Haldex control module as it sits on the Haldex unit and not on the diff per se.
Page 2069


Maybe see if you can get hold a second hand TRC module to test the system? Jules

Thanks Jules .

Steve