Volvo

The cruise control status together with the vehicle speed and calculation of fuel injection are used to maintain the vehicle set speed.
The J1587 and J1939 serial data lines are used as the standard communication link for on-board vehicle instrumentation, off-board service diagnostics and fleet management.
The (VECU) Vehicle Electronic Control Unit is linked to the Engine Control Module (ECM) via these data lines.

Conditions for diagnostic trouble code (DTC):
1) Signal unavailable or not regularly updated

Observable symptoms
1) Cruise control does not function

Probable cause
1) Electronic control unit (ECU), adaptive cruise control (ACC)
2) Vehicle Control Unit (VECU)

The system uses the J1939 data links to control functions and communicates between the vehicle electronic control unit (ECU), the engine control module (ECM), the instrument cluster module and accessory systems, depending on vehicle model and option content.
The J1939 data lines consist of an expandable data bus allowing the addition of accessory control modules. The J1939 data lines are the primary data bus. Data is prioritized and then transmitted across the J1939 data lines to the appropriate control module.

Conditions for diagnostic trouble code (DTC):
1) Message missing on J1939 from the following electronic control unit (ECU): Instrument cluster

Observable symptoms
1) An electronic control unit (ECU) lacking communication with other ECUs can cause a number of symptoms

Probable cause
1) The electronic control unit (ECU) has a software fault or the wrong software version
2) Control unit has no supply voltage
3) Connector
4) Data link

Detailed information
1) Faults on the datalink can be localised by combining this diagnostic trouble code (DTC) with other DTCs
2) It is not probable that the data link is the problem if the diagnostic code (DTC) occurs alone as data link related DTC
3) Faulty software or software version can result in the message being absent from the datalink
4) Guided Diagnostics will automatically detect combination of data link DTCs and refer to another fault tracing procedure
5) If there are no diagnostic trouble codes (DTCs) set by the electronic control unit (ECU) from which data is missing, the cause may be power failure to that ECU

Conditions for diagnostic trouble code (DTC):
1) Instrument Cluster (IC) datalink circuit

Probable cause
1) The electronic control unit (ECU) has a software fault or the wrong software version
2) Control unit has no supply voltage
3) Connector
4) Data link

The system uses the J1939 data links to control functions and communicates between the vehicle electronic control unit (ECU), the engine control module (ECM), the instrument cluster module and accessory systems, depending on vehicle model and option content.
The J1939 data lines consist of an expandable data bus allowing the addition of accessory control modules. The J1939 data lines are the primary data bus. Data is prioritized and then transmitted across the J1939 data lines to the appropriate control module.

Conditions for diagnostic trouble code (DTC):
1) Message missing on J1939 from the following electronic control unit (ECU): Vehicle Control Unit (VECU)

Observable symptoms
1) An electronic control unit (ECU) lacking communication with other ECUs can cause a number of symptoms
2) The engine brake does not function
3) Cruise control does not function
4) The power take-off (PTO) does not function

Probable cause
1) The electronic control unit (ECU) has a software fault or the wrong software version
2) Control unit has no supply voltage
3) Connector
4) Data link

Detailed information
1) Faults on the datalink can be localised by combining this diagnostic trouble code (DTC) with other DTCs
2) It is not probable that the data link is the problem if the diagnostic code (DTC) occurs alone as data link related DTC
3) Faulty software or software version can result in the message being absent from the datalink
4) Guided Diagnostics will automatically detect combination of data link DTCs and refer to another fault tracing procedure
5) If there are no diagnostic trouble codes (DTCs) set by the electronic control unit (ECU) from which data is missing, the cause may be power failure to that ECU

Calibration Number is a calculated value depending on tire revolution/distance, pulses from the output shaft from the transmission and the final gear ratio.

Conditions for diagnostic trouble code (DTC):
1) Calibration Number message not available on the SAE J1587/J1708 data link

Probable cause
1) Vehicle Control Unit (VECU)

The VIN check function is an addition to the immobilizer function. In this function the Engine Control Module (ECM) checks the VIN at number of other electronic control units (ECU:s) and if they are the same engine start is possible. A faulty ECM VIN leads to engine start disabled.

Conditions for diagnostic trouble code (DTC):
1) Engine control Module (ECM) receives no answer to the request for the vehicle identification number (VIN) from either the vehicle electronic control unit (ECU) or the outer lighting control unit (LCM)

Observable symptoms
1) Fuel supply disabled
2) Engine cannot be started

Probable cause
1) Vehicle Control Unit (VECU)
2) Engine control module (ECM)
3) Lighting Control Module (LCM)
4) SAE J1587/J1708 data link

The VIN check function is an addition to the immobilizer function. In this function the Engine Control Module (ECM) checks the VIN at number of other electronic control units (ECU:s) and if they are the same engine start is possible. A faulty ECM VIN leads to engine start disabled.

Conditions for diagnostic trouble code (DTC):
1) Incorrect vehicle identification number (VIN) from vehicle electronic control unit (ECU) or outer lighting control unit (LCM)

Observable symptoms
1) Fuel supply disabled

Probable cause
1) Vehicle Control Unit (VECU)
2) Engine control module (ECM)
3) Lighting Control Module (LCM)