Known-Good ECM/PCM Substitution
WARNING: This page does not describe the selected car, but rather 126 other vehicles, including the 1999 Volvo V70, 1999 Volvo S80, 1999 Volvo S70, 1999 Volvo C70, and 1999 Volkswagen Passat. However, it is still accessible from the selected car via links, so may be relevant.
On models equipped with engine immobilizer system, acquire key cut from non-immobilizer key blank. Remove ECM/PCM from test vehicle. Install a known-good ECM/PCM from donor vehicle into test vehicle. Tape donor vehicle's ignition key head-to-head to test vehicle's temporary key. ECM/PCM will recognize code from donor vehicle's key and allow test vehicle to be started.