HELP with Code 16/ISC Stalling?


Founding Member
Jun 16, 2002

I ran the codes on my car and got a code 16.

16 (r):. ISC can't keep engine from stalling. Check for short to ground in ISC circuit.

What does this mean? Whats the ISC?

And its a 1989 5.0.

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if i had to guess, i would say it is the idle speed controller. i think we normally call it the IAC (idle air controller).
this is just my guess.
The IAB (idle air bypass) solenoid bypasses air around the throttle body plate to help control idle speed. The ecu also advances/retards the timing to make idle speed adjustments.

Code 16 for a KOEO test indicates a problem with the IDM -- specifically that the ecu isn't receiving it's continuous ignition signal. It monitors ignition for a variety of uses - faults in the ignition system, rpm is used to control idle and many other calculations. Code 16 means the ecu isn't receiving the ignition signal it needs.