ELC problem

[Loekee75]

My ELC quit functioning. For a few months the air compressor would come on after shutting the engine off, but would never shut off, causing battery drainage. I would remove the connector from the pump to turn it off. Not long after this, the pump wouldn't come on at all. All ELC fuses are good. I jumped the pump harness straight to the battery and the pump came on, so it's still in working order. Next I replaced the relay, but still no change. I was thinking the next problem could be the level sensors? Does anyone know of this sort of problem or know what direction I should turn to next? Thanks in advance for any help!

[HotZ28]

Under normal operation, the ALC system activates when ignition is turned on, and remains active for 6-min after switching ignition off. If this was not how yours was operating, you either have a bad level sensor, RAC, or BCM module.


The compressor head houses the dump valve. There is an 8-15 sec delay in the sensor circuit, to prevent compressor/dump valve operation during normal driving.

The sensor also limits compressor run time/dump valve, cycle to 6-min in the event of severe system leak; turning ignition on & off resets the run time. This has been known to cause the fuse to blow, or the compressor to overheat or fail. (Too many cycles in a short period of time)


Due to the high cost of replacement parts for the ALC, it might be time to consider installing a manual fill station for about 5-bucks (Monroe Part #AK29)! This option makes it is easier to fine tune your ride & handling and you also save battery drain from the compressor running. I did this about a year ago, and would never go back to the ALC.