Did you update your SLABS unit?

 

Not sure why I would need to the 03 and 04 SLABS are the same.

 

2003 part number is SRD000150. 2004 is SRD500070. The 2004 SLABS recognises the combination of CDL and traction control.

 

I pulled these two out of an 03 (bottom) and an 04 (top). Does that mean that the 04's CDL would physically work but that the computer controlled TC would not be optimized? (they are both 150's if the text in the pic isn't clear)

 

Any of the SLABS units will physically fit, and will most likely work, but the brake mapping is different and some of the systems -- like traction control -- also operate differently. Since the NAS 2003 never came with CDL, its SLABS is not CDL-aware. Strange that you pulled a 150 unit out of a 2004 though.
I do remember that someone reported that a particular year SLABS would not work in their truck, but I don't recall the circumstances.

 

My 2003 was retrofitted with a 2004 transfer case and CDL kit. However, I did not have to change the SLABS ECU. Traction control worked when CDL is engaged.

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More good info on this link: https://discotd5.com/ecu-upgrades/up...e-facelift-d2s

While retro-fitting the CDL lever to 1999-2002MY Discovery 2's is a popular upgrade, it's often followed up with a modification that prevents the SLABS ECU from detecting the CDL has been locked. On the 1999-2002MY D2's the locked CDL triggers a mode of operation that disables Traction Control and reduces the effectiveness of ABS, EBD and HDC.

By cutting the wire from the CDL switch the SLABS ECU operates as if the CDL is unlocked regardless of its actual state.

The 2003 and 2004MY D2's offered the CDL lever as a factory option, and this was fitted to all vehicles imported into Australia. As part of this change Land Rover revised the
programming of the SLABS ECU to work correctly with the locked CDL. While it is difficult to quantify the revised ECU is claimed to have improved ABS and ETC programming, and
I noticed what appeared to be slight improvement in pedal feel after upgrading the ECU in my vehicle.

The main benefit of upgrading to the later ECU is that with the CDL locked the SLABS programming is altered to work in conjunction with the changed power transmission.

There were two variants of the update ECU produced:

SRD000150 which was fitted to 2003MY vehicles
SRD500070 which was originally fitted to 2004MY vehicles

Vehicles built prior to 2003MY should be fitted with a SRD000070, as the ECU revisions prior to this were subject to a recall which mandated installation of the SRD000070 ECU.

The recall - A/B/D 263 issued in 2002 - indicates that metallic debris within the hub can attach to the wheel speed sensor causing the sensor to misread speed, which results in
the SLABS unit incorrectly reducing braking pressure.

The VINs covered by the recall were fitted with SRD100461 or SRD100462 from the factory. If these are still fitted the vehicle has missed the recall.

 

I was just as surprised seeing the 150 in the 04. I thought it was a given that an 04 had an 070. There's always the chance the SLABS was swapped for some unknown reason but it was a two-owner low mileage truck so it's a bit of a mystery. I have to assume there's some difference between the 070 and 150 however reading that .pdf it sounds like other countries (Australia, for one) were able to get a CDL in '03 and were shipped with a 150 so I'm not sure what that difference would actually be.

 

Making progres. We have a Dif lock light but for some reason the brake solenoid allowing me to get out of park is not working. Brakes lights are working

 

Did you remove the brake light switch that contacts the brake pedal. I recently replaced the brake booster and either the reinstall I had to adjust the brake light switch button that contacts the brake pedal

 

Great question but I didn't touch it. My brake lights are all working fine too...I got it on video