In this brief article, we are going to discuss the different Air Suspension issues that occur in Volkswagen Touareg cars, what the causes are, and Troubleshooting Tips.
The Top 3 Most Common problems with Volkswagen Touareg Air Suspension are:
- Self-Leveling Suspension Error Message
- Front suspension Hissing Noise
- Car leaning to one side
How does the Touareg air suspension work?
The Volkswagen Touareg shares the same platform as the Audi Q7 and Porsche Cayenne.
The Touareg comes with optional Air Suspension at all 4 corners. You can set the ride height at different levels varying up to 70mm through a dial in the center console.
The Toureg suspension also has Selectable Driving Modes like ‘Comfort’, ‘Sport, ‘Off-Road’ etc. where the Ride Height is adjusted along with the Damper settings as a combination for each mode. Eventhough the driver selects a particular Ride height, the control module senses vehicle speed and accordingly changes the Ride height automatically, Reduction in Ride height at speeds above 150 km/hr.
The suspension also comes with Adaptive Chassis Control and Active Roll Stabilization, featuring an Electro-mechanical Anti-Roll Bar which can activate and de-activate itself as per the suspension travel and vehicle’s cornering acceleration.
VW Touareg Suspension Error Message
The Error message displayed will look like “Error: running gear”. By ‘Running Gear’, the system means ‘Air Suspension’ in general. The problem could be with any component/s within this system.
Troubleshooting the Suspension Error Message
Checking the Compressor Fuse
- If you notice that the compressor does not turn on, then the first and most easiest thing to troubleshoot would be to check for a blown fuse related to the Self-leveling suspension system Compressor. If the 40A fuse of the compressor is blown, the suspension does not move. The fuse-box is located on the side of the dashboard
Running a system Diagnostic
- If changing the fuse did not remove the error message, then it’s time to run diagnostics and understand which the fault-codes come up.
- If the diagnostics points to –
“01400 Suspension Level Control” , then go to “Read Stream Data” – > “read by List”. This is where you will be able to do a live monitoring of the air suspension parameters by selecting the ones that you want to watch.
Select “Compressor Relay Status”, “Reservoir Tank Pressure” and the “Compressor Temperature”
- Now Turn Off the Suspension “Lock” and watch the “Compressor Relay Status”. If the relay is working properly then it should show the status as ‘ON’.
- At the same time the Reservoir Tank Pressure and Compressor Temperature must normally start to rise, as now the suspension has started working
- The Reservoir tank pressure must, ideally, be able to ramp up to at least 14 bar within 1-2 mins. If it is still stuck at well below 14 bar pressure and not able to rise any further then you will notice that the compressor temperature is still on the rise.
- Eventually, you will see that the system will Turn ‘OFF’ the “Compressor Relay Status” and cut it off as a self-protection mechanism to avoid overheating
- This inability of the Self-Leveling system to achieve 14 bar pressure clearly points to two possible Root causes
- Compressor malfunction
- A leak in the system that is causing the pressure drop
Compressor Pressure – Test
- The Compressor needs to be checked Standalone, if it is capable of producing the required pressure.
- For this, remove the compressor from the car underbody and supply it with ground and power
- There are 2 outlets from the compressor. Connect the Thicker Outlet Hose Pipe to a pressure gauge.
- Block or place a finger on the other Thin outlet pipe so that the compressor can build pressure
- Provide a battery power supply to the compressor terminals to get it started
- If the pressure gauge reads well below 14 bar, then the compressor can be declared as the root cause
- The Compressor can either be replaced or Serviced using a Compressor repair kit depending on what you would prefer. Nevertheless, both ways would work in getting your compressor back to work.
- If you chose to repair the compressor, then you need to repeat the Standalone Pressure Test.
- Once you have recorded a pressure of at least 11-12 Bar in your repaired Compressor, you now need to once again Run a System diagnostic to check for Suspension System-level pressure.
- Repeat the Diagnostic as explained previously. If this test displays a System Pressure of well below 14 Bar, then it is indicative of a Leakage within the Air Suspension Circuit. You can follow the steps explained here for ‘Air Leak’ Testing.
VW Touareg Front suspension Hissing Noise
- The noise starts as soon as the car is started and suspension “Lock” button is turned ‘OFF’
- The “Hissing” Sound is non-stop and throughout the time, unlike a Tire which loses air and stops
Troubleshooting Front suspension Hissing Noise
- Try to get as close as possible to the sound
- The Most probable source of such noise is an Air Leak somewhere within the Air Suspension air-lines. While an air leak is possible anywhere within the circuit, there are certain joints or connections that are more prone to leakages, namely, The Air suspension “Retainer Valve’ located at the top of the Air Bellow
This is a replaceable part available from VW spares and is very easily replaced.
- The next most obvious location would be the Air Spring itself. To check the Air Spring for leakages, do a very simple leakage inspection using Soap water. If there is a leak, you can see it as ‘White Bubbles’ that stick and do not drip down. The procedure for Leakage check is explained here.
VW Touareg Car leaning to one side
The Touareg Air Suspension, sometimes, makes the car lean to one side due to daily use and wear in the suspension, the Suspension sensors are knocked out of their mean position that was originally set at the VW Factory.
When this happens, the Self-adjust mechanism of the suspension does not Level the car Flat, or in other words, one side (either left or right) Ride height is self-adjusted by the Suspension System at a different ride height compared to the opposite side.
TroubleShooting Car Leaning Problem
- You can solve the Touareg Car leaning Problem using a Diagnostic Tool that you plug into the OBD 2.
- In VCDS Select ‘Control Module’ -> “34- Level Control” – “Options” -> “Security Access” and then “Adaption”
- You will need to input the 4 corners’ Ride Height in the software. It then runs a program which will self calibrate and correct the Self- adjust
How to do an ‘Air Leak’ test without a Mechanic on Touareg
Before you begin the test the following conditions must be maintained
- The vehicle and engine must have cooled down sufficiently and should not move for any reason during testing.
- The room/garage temperature should be maintained to be within 50-85º F, and maintained constant throughout the test
- The vehicle must be parked on an absolutely flat level Floor, OR, parked on 2 wooden ramps (left wheels and right wheels)
You can now do an ‘Air Leak’ test on your own by following these steps:
- Turn on the ignition and start your engine
- Set the suspension Ride Height first to “high” and
then set it to “normal” Ride Height using the interactive display.
- Kill the engine.
- Immediately, on the right side of the rear cargo area, Disconnect the Level Control System Control Module connector (Connector ID: J197) to Stop the level-control system from Self-Adjusting the Ride Height.
- Do a measurement of your car’s Ride Height at all four wheels from the center of the wheel to the bottom of the respective Fender Panel.
- After a gap of about two hours, once again measure vehicle Ride Height and compare these values with the measurements you took before (refer previous step).
If the car stands with a lean on any corner, you could conclude that the suspension has a leak. The corner where you observed the greatest difference between the first and second measurement is the location of leakage.
- Use either a Soap-water solution or a leak-detection spray to check the affected air spring shock absorber and its corresponding air inlet/outlet in the following order:
- Air line connections (wiggle the lines to see if the problem leak is present)
- Residual pressure retaining valve, and,
- The Air spring
If there happens to be no deviation at all after the two hour wait, then the measurement must be repeated after 24 hours. After 24 hours, a deviation of up to 4 mm is permissible.
In this brief article we have discussed the different Air Suspension issues that occur in Volkswagen Touareg cars, what the causes are, and Troubleshooting Tips.