Engine Control Module (ECM) Diagnostic Trouble Codes - 7 of 8: Overview Volvo XC70 II

GENERAL INFORMATION

The diagnostic trouble code (DTC) is stored in the event of communication faults on the high speed side of the control area network (CAN). There can be a number of causes for faults in the communication

1. Intermittent open-circuit in one or both CAN cables in part of the network
2. Intermittent short-circuits between the CAN cables
3. Intermittent short-circuits between one of the CAN cables and ground or supply voltage
4. Fault in the communication circuit in one or more control modules
5. Internal fault in a control module on the CAN network that results in the control module transmitting faulty messages on the CAN network.

In the event of a diagnostic trouble code (DTC) for a communication fault in the relevant control module, any diagnostic trouble codes (DTCs) in the central electronic module (CEM) must also be checked. The central electronic module (CEM) monitors the voltage level in the CAN cables. The central electronic module (CEM) is the only control module that can directly store a diagnostic trouble code (DTC) for a short-circuit in one of the cables for ground or supply voltage. Do not replace the central electronic module (CEM) in the event of a CAN fault unless fault-tracing has indicated that the central electronic module (CEM) has an internal fault.

In order to check the control area network (CAN) cables, the resistance in the network must be measured.

Other information

1. see «GENERAL INFORMATION ABOUT FAULT-TRACING IN THE CAN NETWORK»(ref-495323-S26252627522012082100000)

1. Continue Refer to «TAKING READING ON CABLE IN THE CAN NETWORK (HS-CAN)»(ref-495396-S21662272372012082100000)

Scheme 158

1. Disconnect the battery negative lead.
2. Remove the central electronic module (CEM)
3. Connect the breakout box to the cable harness for the central electronic module (CEM). Do not connect the central electronic module (CEM). HINT: Where a breakout box cannot be used, take readings from the rear of the affected connectors if possible. This prevents terminal pins and socket housings being damaged. Disconnect the CAN network to make it easier to locate a fault. A suitable point to disconnect the network is at the central electronic module (CEM). Fault-tracing therefore starts from the central electronic module (CEM). Take resistance readings across the following terminals. Various readings will be obtained due to the structure of the network. Twist the cable harness and work the connectors at accessible points along the cable harness in order to check whether the resistance changes during each measurement. This method can be used to detect intermittent short-circuits or open-circuits. NOTE: The following resistance readings only measure the main arteries in the high speed network, not the junctions that exist for some control modules. If an open-circuit is suspected in a cable, or a short-circuit is suspected in one of its junctions, the connector at the control module for this junction must be disconnected and the reading taken from there. Take the following readings Resistance between C3:47 and C3:48. Resistance should be 120 ohms. NOTE: Measuring will only give value 120 ohms if the main circuit in the CAN-net is intact. If there is a short-circuit somewhere in the CAN-net (either main circuit or other branching) the resistance will be 0 ohms. The resistance between C3:48 and a connection to voltage as well as between C3:48 and a short-circuit to ground. The resistance shall be very high (more than 1 Mohms). The resistance between C3:47 and a connection to voltage as well as between C3:47 and a short-circuit to ground. The resistance shall be very high (more than 1 Mohms). HINT: Any short-circuit detected on the CAN-net may be on the main circuit or on any branching running out to some control modules. If a fault is found, try to disconnect the junction with the fault at a point further forward. Try to locate the fault in this way. Remedy as necessary. Other information see «BATTERY DISCONNECTING AND CONNECTING»(ref-495407-S17646253862012082100000) see «CONNECTING THE BREAKOUT BOX»(ref-495323-S29210678802012082100000) see «SIGNAL SPECIFICATION»(ref-495325-S00863282382012082100000) see «CHECKING WIRING AND TERMINALS»(/volvo/xc70/ii-2007-2013/remont/body-electrical/#wiring-and-terminals-general-diagnostics-and-tests)

Was a fault detected?

1. YES Refer to «VERIFICATION»(ref-495396-S07936890702012082100000)
2. NO Refer to «CHECKING THE TRAFFIC LOAD ON THE CAN CABLES»(ref-495396-S20531051182012082100000)

The diagnostic trouble code (DTC) is stored in the event of communication faults on the high speed side of the control area network (CAN). There can be a number of causes for faults in the communication

1. Intermittent open-circuit in one or both CAN cables in part of the network
2. Intermittent short-circuits between the CAN cables
3. Intermittent short-circuits between one of the CAN cables and ground or supply voltage
4. Fault in the communication circuit in one or more control modules
5. Internal fault in a control module on the CAN network that results in the control module transmitting faulty messages on the CAN network.

In the event of a diagnostic trouble code (DTC) for a communication fault in the relevant control module, any diagnostic trouble codes (DTCs) in the central electronic module (CEM) must also be checked. The central electronic module (CEM) monitors the voltage level in the CAN cables. The central electronic module (CEM) is the only control module that can directly store a diagnostic trouble code (DTC) for a short-circuit in one of the cables for ground or supply voltage. Do not replace the central electronic module (CEM) in the event of a CAN fault unless fault-tracing has indicated that the central electronic module (CEM) has an internal fault.

In order to check the control area network (CAN) cables, the resistance in the network must be measured.

Other information

1. see «GENERAL INFORMATION ABOUT FAULT-TRACING IN THE CAN NETWORK»(ref-495323-S26252627522012082100000)

1. Continue Refer to «TAKING READING ON CABLE IN THE CAN NETWORK (HS-CAN)»(ref-495396-S23520227602012082100000)

The diagnostic trouble code (DTC) is stored in the event of communication faults on the high speed side of the control area network (CAN). There can be a number of causes for faults in the communication

1. Intermittent open-circuit in one or both CAN cables in part of the network
2. Intermittent short-circuits between the CAN cables
3. Intermittent short-circuits between one of the CAN cables and ground or supply voltage
4. Fault in the communication circuit in one or more control modules
5. Internal fault in a control module on the CAN network that results in the control module transmitting faulty messages on the CAN network.

In the event of a diagnostic trouble code (DTC) for a communication fault in the relevant control module, any diagnostic trouble codes (DTCs) in the central electronic module (CEM) must also be checked. The central electronic module (CEM) monitors the voltage level in the CAN cables. The central electronic module (CEM) is the only control module that can directly store a diagnostic trouble code (DTC) for a short-circuit in one of the cables for ground or supply voltage. Do not replace the central electronic module (CEM) in the event of a CAN fault unless fault-tracing has indicated that the central electronic module (CEM) has an internal fault.

In order to check the control area network (CAN) cables, the resistance in the network must be measured.

Other information

1. see «GENERAL INFORMATION ABOUT FAULT-TRACING IN THE CAN NETWORK»(ref-495323-S26252627522012082100000)

1. Continue Refer to «TAKING READING ON CABLE IN THE CAN NETWORK (HS-CAN)»(ref-495396-S02934718312012082100000)

The diagnostic trouble code (DTC) is stored in the event of communication faults on the high speed side of the control area network (CAN). There can be a number of causes for faults in the communication

1. Intermittent open-circuit in one or both CAN cables in part of the network
2. Intermittent short-circuits between the CAN cables
3. Intermittent short-circuits between one of the CAN cables and ground or supply voltage
4. Fault in the communication circuit in one or more control modules
5. Internal fault in a control module on the CAN network that results in the control module transmitting faulty messages on the CAN network.

In the event of a diagnostic trouble code (DTC) for a communication fault in the relevant control module, any diagnostic trouble codes (DTCs) in the central electronic module (CEM) must also be checked. The central electronic module (CEM) monitors the voltage level in the CAN cables. The central electronic module (CEM) is the only control module that can directly store a diagnostic trouble code (DTC) for a short-circuit in one of the cables for ground or supply voltage. Do not replace the central electronic module (CEM) in the event of a CAN fault unless fault-tracing has indicated that the central electronic module (CEM) has an internal fault.

In order to check the control area network (CAN) cables, the resistance in the network must be measured.

Other information

1. see «GENERAL INFORMATION ABOUT FAULT-TRACING IN THE CAN NETWORK»(ref-495323-S26252627522012082100000)

1. Continue Refer to «TAKING READING ON CABLE IN THE CAN NETWORK (HS-CAN)»(ref-495396-S18342655312012082100000)

Scheme 159

1. Disconnect the battery negative lead.
2. Remove the central electronic module (CEM)
3. Connect the breakout box to the cable harness for the central electronic module (CEM). Do not connect the central electronic module (CEM). HINT: Where a breakout box cannot be used, take readings from the rear of the affected connectors if possible. This prevents terminal pins and socket housings being damaged. Disconnect the CAN network to make it easier to locate a fault. A suitable point to disconnect the network is at the central electronic module (CEM). Fault-tracing therefore starts from the central electronic module (CEM). Take resistance readings across the following terminals. Various readings will be obtained due to the structure of the network. Twist the cable harness and work the connectors at accessible points along the cable harness in order to check whether the resistance changes during each measurement. This method can be used to detect intermittent short-circuits or open-circuits. NOTE: The following resistance readings only measure the main arteries in the high speed network, not the junctions that exist for some control modules. If an open-circuit is suspected in a cable, or a short-circuit is suspected in one of its junctions, the connector at the control module for this junction must be disconnected and the reading taken from there. Take the following readings Resistance between C3:47 and C3:48. Resistance should be 120 ohms. NOTE: Measuring will only give value 120 ohms if the main circuit in the CAN-net is intact. If there is a short-circuit somewhere in the CAN-net (either main circuit or other branching) the resistance will be 0 ohms. The resistance between C3:48 and a connection to voltage as well as between C3:48 and a short-circuit to ground. The resistance shall be very high (more than 1 Mohms). The resistance between C3:47 and a connection to voltage as well as between C3:47 and a short-circuit to ground. The resistance shall be very high (more than 1 Mohms). HINT: Any short-circuit detected on the CAN-net may be on the main circuit or on any branching running out to some control modules. If a fault is found, try to disconnect the junction with the fault at a point further forward. Try to locate the fault in this way. Remedy as necessary. Other information see «BATTERY DISCONNECTING AND CONNECTING»(ref-495407-S17646253862012082100000) see «CONNECTING THE BREAKOUT BOX»(ref-495323-S29210678802012082100000) see «SIGNAL SPECIFICATION»(ref-495325-S00863282382012082100000) see «CHECKING WIRING AND TERMINALS»(/volvo/xc70/ii-2007-2013/remont/body-electrical/#wiring-and-terminals-general-diagnostics-and-tests)

Was a fault detected?

1. YES Refer to «VERIFICATION»(ref-495396-S23440230792012082100000)
2. NO Refer to «CHECKING THE TRAFFIC LOAD ON THE CAN CABLES»(ref-495396-S15642679632012082100000)

The diagnostic trouble code (DTC) is stored in the event of communication faults on the high speed side of the control area network (CAN). There can be a number of causes for faults in the communication

1. Intermittent open-circuit in one or both CAN cables in part of the network
2. Intermittent short-circuits between the CAN cables
3. Intermittent short-circuits between one of the CAN cables and ground or supply voltage
4. Fault in the communication circuit in one or more control modules
5. Internal fault in a control module on the CAN network that results in the control module transmitting faulty messages on the CAN network.

In the event of a diagnostic trouble code (DTC) for a communication fault in the relevant control module, any diagnostic trouble codes (DTCs) in the central electronic module (CEM) must also be checked. The central electronic module (CEM) monitors the voltage level in the CAN cables. The central electronic module (CEM) is the only control module that can directly store a diagnostic trouble code (DTC) for a short-circuit in one of the cables for ground or supply voltage. Do not replace the central electronic module (CEM) in the event of a CAN fault unless fault-tracing has indicated that the central electronic module (CEM) has an internal fault.

In order to check the control area network (CAN) cables, the resistance in the network must be measured.

Other information

1. see «GENERAL INFORMATION ABOUT FAULT-TRACING IN THE CAN NETWORK»(ref-495323-S26252627522012082100000)

1. Continue Refer to «TAKING READING ON CABLE IN THE CAN NETWORK (HS-CAN)»(ref-495396-S18500848032012082100000)

The diagnostic trouble code (DTC) is stored in the event of communication faults on the high speed side of the control area network (CAN). There can be a number of causes for faults in the communication

1. Intermittent open-circuit in one or both CAN cables in part of the network
2. Intermittent short-circuits between the CAN cables
3. Intermittent short-circuits between one of the CAN cables and ground or supply voltage
4. Fault in the communication circuit in one or more control modules
5. Internal fault in a control module on the CAN network that results in the control module transmitting faulty messages on the CAN network.

In the event of a diagnostic trouble code (DTC) for a communication fault in the relevant control module, any diagnostic trouble codes (DTCs) in the central electronic module (CEM) must also be checked. The central electronic module (CEM) monitors the voltage level in the CAN cables. The central electronic module (CEM) is the only control module that can directly store a diagnostic trouble code (DTC) for a short-circuit in one of the cables for ground or supply voltage. Do not replace the central electronic module (CEM) in the event of a CAN fault unless fault-tracing has indicated that the central electronic module (CEM) has an internal fault.

In order to check the control area network (CAN) cables, the resistance in the network must be measured.

Other information

1. see «GENERAL INFORMATION ABOUT FAULT-TRACING IN THE CAN NETWORK»(ref-495323-S26252627522012082100000)

1. Continue Refer to «TAKING READING ON CABLE IN THE CAN NETWORK (HS-CAN)»(ref-495396-S12748874712012082100000)

The diagnostic trouble code (DTC) is stored in the event of communication faults on the high speed side of the control area network (CAN). There can be a number of causes for faults in the communication

1. Intermittent open-circuit in one or both CAN cables in part of the network
2. Intermittent short-circuits between the CAN cables
3. Intermittent short-circuits between one of the CAN cables and ground or supply voltage
4. Fault in the communication circuit in one or more control modules
5. Internal fault in a control module on the CAN network that results in the control module transmitting faulty messages on the CAN network.

In the event of a diagnostic trouble code (DTC) for a communication fault in the relevant control module, any diagnostic trouble codes (DTCs) in the central electronic module (CEM) must also be checked. The central electronic module (CEM) monitors the voltage level in the CAN cables. The central electronic module (CEM) is the only control module that can directly store a diagnostic trouble code (DTC) for a short-circuit in one of the cables for ground or supply voltage. Do not replace the central electronic module (CEM) in the event of a CAN fault unless fault-tracing has indicated that the central electronic module (CEM) has an internal fault.

In order to check the control area network (CAN) cables, the resistance in the network must be measured.

Other information

1. see «GENERAL INFORMATION ABOUT FAULT-TRACING IN THE CAN NETWORK»(ref-495323-S26252627522012082100000)

1. Continue Refer to «TAKING READING ON CABLE IN THE CAN NETWORK (HS-CAN)»(ref-495396-S31689973262012082100000)

The diagnostic trouble code (DTC) is stored in the event of communication faults on the high speed side of the control area network (CAN). There can be a number of causes for faults in the communication

1. Intermittent open-circuit in one or both CAN cables in part of the network
2. Intermittent short-circuits between the CAN cables
3. Intermittent short-circuits between one of the CAN cables and ground or supply voltage
4. Fault in the communication circuit in one or more control modules
5. Internal fault in a control module on the CAN network that results in the control module transmitting faulty messages on the CAN network.

In the event of a diagnostic trouble code (DTC) for a communication fault in the relevant control module, any diagnostic trouble codes (DTCs) in the central electronic module (CEM) must also be checked. The central electronic module (CEM) monitors the voltage level in the CAN cables. The central electronic module (CEM) is the only control module that can directly store a diagnostic trouble code (DTC) for a short-circuit in one of the cables for ground or supply voltage. Do not replace the central electronic module (CEM) in the event of a CAN fault unless fault-tracing has indicated that the central electronic module (CEM) has an internal fault.

In order to check the control area network (CAN) cables, the resistance in the network must be measured.

Other information

1. see «GENERAL INFORMATION ABOUT FAULT-TRACING IN THE CAN NETWORK»(ref-495323-S26252627522012082100000)

1. Continue Refer to «TAKING READING ON CABLE IN THE CAN NETWORK (HS-CAN)»(ref-495396-S34918178922012082100000)

See also:
• CONNECTING THE BREAKOUT BOX
• SIGNAL SPECIFICATION
• CHECKING WIRING AND TERMINALS
• CONNECTING THE BREAKOUT BOX
• DESCRIPTION OF STATUS IDENTIFIER
• DESCRIPTION OF COUNTER
• COMPONENT SPECIFICATIONS
• SIGNAL SPECIFICATION
• CONTENTS
• RADIATOR