Preliminary Check
WARNING: This page is about a different car, the 1994 Volvo 960, 1994 Volvo 940, and 1994 Volvo 850. However, it is still accessible from the selected car via links, so may be relevant.
Turn ignition off. Disconnect ECU connector. ECU is located behind panel on right side of accelerator pedal. Visually inspect all terminal connector sleeves to ensure no terminals are damaged.