P20F9 Intake Manifold Runner Control Circuit Performance (Bank 2)

P20F9 is the bank 2 counterpart of P20F8: the runner or swirl flaps of the second cylinder bank do not track their commanded position. It needs a V engine whose banks have separately driven flaps, each with its own position feedback. No manufacturer documents this code publicly; GM and Mazda only use the bank 1 code P20F8. GM's diesel logic for P20F8 shows how such a test works: set point and measured position are compared continuously, and a deviation above 10 % in most samples counts as a fault with warm coolant and a supply above 11 V. CARB's comprehensive component rules require functional checks of such actuators where they affect emissions. Directional faults on bank 2 are P2005 (stuck open) and P2007 (stuck closed); electrical faults are P2011–P2013. Expect the MIL and possibly uneven running between banks.

Likely causes

Symptoms

• Malfunction indicator lamp on
• Uneven idle or reduced torque at low speed

Repair estimate

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

Related codes

References: gsi.ext.gm.com, law.cornell.edu.