How to use OBD on 240, 740, 760, 780, 940 and 960

Let’s talk about the On-Board Diagnostic unit

OBD unit is in the engine compartment

The Volvo 240, 740, 760, 780, 940 and 960 cars from 1989, non-turbo engines only and 1990 to 1995 for both turbo and non-turbo engines were fitted with an On-Board Diagnostic (OBD) unit in the engine compartment. It is mounted behind the left strut assembly and can be used to check for Diagnostic Trouble Codes (DTC), more commonly known as fault codes, in both fuel injection and ignition systems.

This tool is a first step in diagnosing engine problems. Unlike the later models you do not need a scan tool to read the codes.

How to use the On-Board Diagnostic (OBD) unit.

billofdurham » The 240, 740, 760, 780, 940 and 960 cars from 1989, non-turbo engines only and 1990 to 1995 for both turbo and non-turbo engines were fitted with an On-Board Diagnostic (OBD) unit in the engine compartment. It is mounted behind the left strut assembly and can be used to check for Diagnostic Trouble Codes (DTC), more commonly known as fault codes, in both fuel injection and ignition systems.

This tool is a first step in diagnosing engine problems. Unlike the later models you do not need a scan tool to read the codes.

The first attachment has instructions for using the unit on the 200, 700 and 940 with a list of codes, which may not apply to all models/years. It also contains some further checks to be carried out when certain codes are detected.

NB Erase the codes using the OBD unit. DO NOT disconnect the battery cable until you have checked that the codes have been deleted. If the flash code 1-1-1 is received the codes have been deleted. If the flash code 1-1-1 is not received then disconnect the battery cable to erase the codes. Disconnecting the battery cable will force the computer into a relearn mode which can produce some driveability problems until it has gone through this process. This is something best avoided.

The second attachment has instructions for using the unit on the 960 which has a different different type of ECU.

• 200; 700; 940 tests with codes.pdf This is an updated list of codes for the 940
• Amended 940 DTCs.pdf(453.56 KiB)
• 960 tests with codes.pdf(842.77 KiB) This is an updated list of codes for the 960
• 960 Fault code list.pdf(3.66 MiB)