Air suspension compressor running excessively due to a leak in the air lines or air springs; Restricted or blocked compressor intake filter or exhaust valve; Faulty compressor relay or wiring causing continuous operation; Degraded compressor motor drawing higher current and generating excess heat; Ambient temperature sensor or compressor temperature sensor giving inaccurate readings; Control module software issue or internal fault in the suspension control module

DTC codes / C08xx · Brakes, steering and suspension / C0815

C0815Air Suspension Compressor Overtemperature

Q: What does code C0815 mean?

Air Suspension Compressor Overtemperature. C0815 indicates that the air suspension control module has detected an overtemperature condition at the compressor, typically because the compressor has run too long or too frequently without adequate cooling. The module sets this code when the compressor's thermal protection strategy is triggered, often disabling the system until temperatures return to normal.

C0815 indicates that the air suspension control module has detected an overtemperature condition at the compressor, typically because the compressor has run too long or too frequently without adequate cooling. The module sets this code when the compressor's thermal protection strategy is triggered, often disabling the system until temperatures return to normal.

SystemChassis

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaBrakes, steering and suspension

Symptoms you may notice

Air suspension warning light illuminated on the dashboard
Vehicle may sit lower than normal or at an uneven ride height
Compressor may be heard running excessively or not at all
Ride quality becomes harsh or bouncy due to inactive suspension
Often no symptoms besides the warning light, especially if the fault is intermittent
System may temporarily recover after the compressor cools down

Common causes, most likely first

Air suspension compressor running excessively due to a leak in the air lines or air springs
Restricted or blocked compressor intake filter or exhaust valve
Faulty compressor relay or wiring causing continuous operation
Degraded compressor motor drawing higher current and generating excess heat
Ambient temperature sensor or compressor temperature sensor giving inaccurate readings
Control module software issue or internal fault in the suspension control module

How to diagnose and fix it

Inspect the compressor intake filter and air lines for restrictions or leaks
Check for air spring leaks using soapy water or a smoke test
Verify compressor relay and wiring for signs of overheating or continuous power
Measure compressor current draw and compare to specification
Test the compressor temperature sensor and ambient temperature sensor for proper resistance
Inspect the compressor for physical damage or excessive wear and replace if necessary
Clear the code and perform a system calibration or relearn procedure if required

Why the compressor overheats without a leak

A restricted intake filter is a commonly overlooked cause that forces the compressor to work harder and overheat.
The code can set from a single long run cycle, such as after the vehicle has been parked for weeks and the system tries to level repeatedly.
A failing compressor relay that sticks closed can power the compressor continuously, even with the key off, leading to overtemperature.
The control module may set this code as a protective measure even when the compressor itself is healthy, so always check for excessive run time triggers.
After replacing the compressor, the system may need a calibration or learn procedure to prevent repeated overtemperature codes.

Can I keep driving with C0815?

You can usually drive the vehicle with this code, but the air suspension may be disabled, resulting in a stiffer ride and reduced ground clearance. Avoid loading the vehicle heavily or driving at high speeds until the fault is repaired, as handling and stability may be affected.

Tools that help

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Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.