Cadillac P1508: Idle Speed Low - IAC Control System Not Responding

What Does The Cadillac P1508 Code Mean?

DTC P1370, P1371, P1406, P1441 and P1442 not set, engine started, vehicle not moving, ECT sensor from -4ºF to 230ºF, BARO sensor over 65 kPa, engine runtime over 10 seconds in closed loop, MAF sensor from 2-35 g/sec, Actual idle speed 80 rpm.

What Are The Symptoms Of The Cadillac P1508 Code?

Slow or unstable idle speed

What Are The Potential Causes Of The Cadillac P1508 Code?

• Base engine problem causing a slow or unstable idle speed
• Fuel system is too rich or too lean
• IAC motor is damaged or has failed (it may be sticking)
• Throttle body plate or bore contaminated with foreign material
• Throttle body adjustment screw tampere

Recommended Parts

Below are some recommended auto parts to help you address the trouble code affecting your vehicle and get it running smoothly again:

Note: During the purchasing process, please check carefully whether the part you want to buy fits your car!

Reference Sources

GM, 2013, Service Bullettin – Prior To Any Circuit Testing.