Checking engine control module (ECM) ground terminals

WARNING: This page is about a different car, the 2002 Volvo C70, 2001 Volvo C70, 2000 Volvo C70, 1999 Volvo C70, and 1998 Volvo C70. However, it is still accessible from the selected car via links, so may be relevant.

Fig 1: Identifying Ignition Switch OFF Position

Courtesy of VOLVO CARS OF NORTH AMERICA.

Fig 2: Identifying Connector

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Fig 3: Identifying Control Unit

Courtesy of VOLVO CARS OF NORTH AMERICA.

Ignition off.
Engine speed (RPM) sensor disconnected.
Check engine control module (ECM) connector and ground terminals 31/32 and 31/33 for contact resistance and oxidation and remedy according to Contact resistance and oxidation .
Control module connected.
Connect an ohmmeter between engine speed (RPM) sensor connector terminal 2 (engine control module (ECM) side) and ground.

Fig 4: Identifying 2-Pin Connector
Courtesy of VOLVO CARS OF NORTH AMERICA.

Fig 5: Identifying Ohmmeter
Courtesy of VOLVO CARS OF NORTH AMERICA.

The ohmmeter should read approximately 0 Ω.

OK
Refer to Checking signal cable resistance to ground
NOT OK
Refer to Checking for an open-circuit