View Full Version : VAG code help (16890)

11-01-2004, 07:24 AM
16890 - Idle Control sstem RPM lower then expected

what does this mean?

my idle has been shitty lately, and I'm going to try to replace the plugs, but I think it may be something else like the Idle control motor?!?[confused]

11-01-2004, 10:15 AM
I can check the remedies listed in my Bentley manual tomorrow. I left my laptop at work.

11-02-2004, 07:16 AM
Bentley recommends the following actions to correct the problem:

- Check throttle valve control module Page 24-120

- Check hose setup (Secondary Air Injection -AIR- solenoid valve); check intake system for leaks (false air) Page 24-68

The throttle valve control module is the servo that operates the throttle body via the DBW system. Clear the error codes and then do a TB alignment. Then re-check your idle.

If this doesn't help, you may have a leaky hose or coupler that is letting pirated air in after the MAF. You should check all hoses that carry air from the airbox to the turbo, IC and TB. Air leaks will cause the car to bump up the idle to compensate. In addition, you will leak boost under WOT and run rich.