Diagnostic Procedure

Ignition OFF. Check boost pressure sensor connector for contact resistance and oxidation. See CHECKING WIRING & CONNECTIONS . Repair as necessary and verify. Reconnect connector. Ignition ON. Read out boost pressure sensor signal using a scan tool. Check that signal is within its permitted range. With engine switched off voltage should be approximately 1.9 volts. If signal is now OK, fault was caused by poor connection. If fault remains, go to next step.
Connect breakout box. See CONNECTING & DISCONNECTING BREAKOUT BOX .
Check signal cable between PCM terminal A23 and boost pressure sensor connector Pin 1 for an open circuit, a short to ground and a short to supply voltage. With ignition on and boost pressure sensor connector disconnected, voltage between Pin 1 and ground terminal should be approximately 5 volts.
Check ground lead between PCM terminal A60 and boost pressure sensor boost pressure sensor terminal No. 2 for an open circuit. Repair as necessary and go to next step.
Disconnect breakout box. See CONNECTING & DISCONNECTING BREAKOUT BOX . Verify repair. Ignition OFF. Reconnect connectors and reinstall components. Ignition ON. Read out boost pressure sensor signal using scan tool. Voltage should be approximately 1.9 volts. If not, go to next step.
Ignition OFF. Replace sensor with a known good unit. Sensor is located on intake manifold at front of engine. See Fig 1.
Turn ignition on with new sensor installed and read out boost pressure value using a scan tool. With engine switched off voltage should be approximately 1.9 volts. If signal is now OK, fault was caused by a defective sensor.

Fig 1: Locating Boost Pressure Sensor

Courtesy of VOLVO CARS OF NORTH AMERICA.