Conditions for Setting the DTC
WARNING: This page is about a different car, the 2007 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.
P2520
- The ECM detects a short to ground on the a/c request circuit of the HVAC control module.
- The ECM detects the a/c request signal circuit that has a PWM cycle of less than 10%.
P2521
- The ECM detects a short to voltage on the a/c request circuit of the HVAC control module.
- The ECM detects the a/c request signal circuit that has a PWM cycle of greater than 70%.