Air Suspension ECU

SUSPENSION

60-16

DESCRIPTION AND OPERATION

External Pressure Relief Valve
On vehicles from VIN 106310 onwards, the maximum system pressure was reduced from 13.7 to 11.8 bar (199 to 
171 lbf/in

2

) with the introduction of a new level of software for the air suspension ECU. For systems running with the 

higher operating pressure, a relief valve in the air supply unit protects the subsequent components in the circuit. The 
relief valve in the air supply unit became redundant with the introduction of the lower maximum system pressure, so 
an external pressure relief valve was introduced to maintain protection.

The external pressure relief valve is installed in the air pipe between the compressor and the reservoir, in the front 
right corner of the spare wheel well. If the pressure of the air from the compressor increases to 12.3 bar (178 lbf/in

2

), 

the pressure relief valve opens and releases excess pressure to atmosphere.

External Pressure Relief Valve Location

Leak Detection
Leak detection can be carried out using a Land Rover approved leak detection spray. 

If the vehicle appears to be leaking, perform a leak check on all aspects of the system, i.e.; air spring hose fittings and 
the associated connections on the valve block and cross-link valve, air springs, reservoir. Failure to correctly diagnose 
leakage will result in unnecessary exchange of serviceable components and recurrence of original problem.

Air Suspension ECU
The air suspension ECU monitors vehicle ride height via four height sensors. The ECU has three modes of operation:

l

Normal

l

Periodic Wake-Up

l

Transportation.

When a new air suspension ECU is fitted, the air suspension system will not function until configured with TestBook/
T4.