Possible Causes
WARNING: This page is about a different car, the 1996 Volvo 850. However, it is still accessible from the selected car via links, so may be relevant.
This DTC is always stored with DTC 446 - PULSED SECONDARY AIR INJECTION SYSTEM (PAIR) PUMP FLOW FAULT or DTC 448 - PULSED SECONDARY AIR INJECTION SYSTEM (PAIR) PUMP FLOW FAULT . If scan tool indicates PERMANENT FAULT, LEAKAGE, or INTERMITTENT FAULT, LEAKAGE, go to DTC 446 - PULSED SECONDARY AIR INJECTION SYSTEM (PAIR) PUMP FLOW FAULT . If scan tool indicates PERMANENT FAULT, FLOW TOO LOW, or INTERMITTENT FAULT, FLOW TOO LOW, go to DTC 448 - PULSED SECONDARY AIR INJECTION SYSTEM (PAIR) PUMP FLOW FAULT .