For the last few weeks I’ve had a few suspicions about my suspension: I noticed the car was sitting unevenly whilst stopped by what seemed to be 10 to 15mm at the back LHS. It was holding it’s height okay overnight and all else seemed okay so I decided to leave it for a while and do a guided suspension calibration when I next had time.

I’ve been trying to complete the guided suspension calibration over the last few days and had some issues which you can read about here https://www.fullfatrr.com/forum/post648179.html#648179

So today whilst on a short run ( thankfully ) I have a “suspension failed” warning on the dash. Over the next few hundred meters the car dropped onto the bump stops. After a break I was able restart and select normal height in response to a “confirm suspension height” message on the dash. I made it half way home before the same suspension failed warning appeared and back down on the bump stops again.

I’ve read the fault code as follows and am beginning the diagnosis; any advice appreciated!

Particularly on how to lookup the fault code.

Click image to enlarge

Hi Ramblin

I usually enter the fault code in Google and see what OBD hits come back.

On yours it appears this is a generic ABS related code (not suspension) :

Quote:

A U0415 code is a generic diagnostic trouble code that occurs when the PCM/ECM detects the ABS control module signal voltage input that is invalid, implausible, erratic, or that otherwise falls outside of the expected range. The ABS module compares the rotational speeds of each wheel and transmits this information to the PCM (Powertrain Control Module) if the ABS system is operating effectively. This module shares data with other systems, such as the Stability and Traction Control Module.

Quote:

Common causes for this code include:

Wiring and/or connectors that are damaged, burnt, shorted, disconnected, or corroded
There may be an issue with one or more Wheel Speed Sensors, but additional fault codes will be displayed in this case.
The ABS pump’s function might be damaged.
The Anti-Lock Brake System Control Module may have a defect

Quote:

To diagnose a U0415 DTC code, a technician would:

Scan for codes in the ECM and look at the freeze frame data for failure.
Visually inspect all wiring and connectors.
Test the Wheel Speed Sensors for resistance and continuity.
Check for voltage on the power and ground circuits.
Measure the current draw on the ABS pump motor.
Remove, test, and replace the ABS Control Module as necessary

You have identified a faulty height sensor so this would drop the suspension if it was giving the ECU a lower height than the others as the car would try to level itself. Fit a new sensor and recalibrate. 2012 TDV8 Vogue (L322)

Thanks @JayGee I’ll order one up and breakout the spanner’s and trolley jack.

I’ll probably do the swap on the next dry day we get and I’ll report back afterwards TDV8 4.4 2012

Sounds like the same issue I had awhile back, new sensor and all everything sorted.

Just dont drive it till you do it or you might damage the pump depending on what it is being told to do

The free download workshop manual in the Wiki has all the DTC (diagnostic trouble codes) in a chapter  Gone to a good home: 2011 4.4 TDV8 Vogue SE Buckingham Blue with Ivory and clear glass = "Rory"
New Defender D300 90
1974 Series 3 Lightweight = "Millie"
My preferred specialist: www.glenrands.co.uk
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JayGee wrote:

You have identified a faulty height sensor so this would drop the suspension if it was giving the ECU a lower height than the others as the car would try to level itself. Fit a new sensor and recalibrate.

The height sensor fault was identified in the other thread. 2012 TDV8 Vogue (L322)

Aaaah! Thank you.