Checking wiring

Check the engine control module (ECM) and air conditioning (A/C) pressure sensor connectors. Check for contact resistance and oxidation according to Contact resistance and oxidation .

Check in particular for damage or loose terminal pins.

Check the signal cable between engine control module (ECM) terminal #14 and air conditioning (A/C) pressure sensor terminal 2. Check for an intermittent short-circuit to supply voltage according to Short-circuit to supply voltage, intermittent faults . Remedy if necessary.

Check the ground lead between engine control module (ECM) terminal #77 and air conditioning (A/C) pressure sensor terminal 1. Check for an intermittent open-circuit according to Open-circuit, intermittent faults . Remedy if necessary.

Try a new air conditioning (A/C) pressure sensor if no faults are found in the above fault-tracing.

Other information 

• To connect the breakout box, see Connecting the breakout box. EMS 2000
• To replace the air conditioning (A/C) pressure sensor, see Replacing the air conditioning (A/C) system pressure sensor .

Fig 1: Identifying Knock Sensor (KS) Connector Terminals

Courtesy of VOLVO CARS OF NORTH AMERICA.

Fig 2: Identifying Ohmmeter

Courtesy of VOLVO CARS OF NORTH AMERICA.

Fig 3: Identifying EMS2000

Courtesy of VOLVO CARS OF NORTH AMERICA.

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