Electrical System - Signal Specifications: Other Volvo V70 II

Checking the power supply and ground for the steering wheel module (SWM)

Note. Steering wheel angle sensor module (SAS) is located inside, and is supplied with power by, the steering wheel module (SWM). Only the steering wheel angle sensor module (SAS) communicates on the controller area network (CAN). The brake control module (BCM) will store a diagnostic trouble code (DTC) if the communication between the brake control module (BCM) and the steering wheel angle sensor module (SAS) has been interrupted. DSTC will not be activated after a fault in the system has been repaired until the vehicle reaches a speed of approximately 50 km/h.

Check that the fuse for the control module is intact.

Check the power supply and ground for the steering wheel module (SWM) as follows.

Remedy as necessary.

Other information

1. See «Checking the voltage / ground terminal»(ref-406850-S18975103692011070100000)
2. For information about fuse and terminal numbers, see the appropriate SYSTEM WIRING DIAGRAM article.
3. See «Contents»(ref-406811-S37635188302011070100000)

Was a fault detected?

1. YES Refer to «Checking the steering wheel angle sensor module (SAS)»(ref-406816-S02785733342011070100000)
2. NO Refer to «Checking communication with the steering wheel angle sensor module (SAS)»(ref-406816-S08049153752011070100000)

Checking communication with the steering wheel angle sensor module (SAS)

HINT: The CAN communication with the control module is probably OK if the control module ID can be read off. In that case the fault is probably intermittent and will then be more difficult to trace.

Scheme 15

1. Try to communicate with the steering wheel angle sensor module (SAS) by reading off the control module ID
2. Click on the symbol for VCT2000 to begin reading off

1. Continue Refer to «Signal missing»(ref-406816-S24125445242011070100000)

Checking the steering wheel angle sensor module (SAS)

HINT: After carrying out the repair, check that the fault has been remedied.

Scheme 16

Scheme 17

1. Ignition off
2. Reconnect the connectors. Reinstall the components
3. Ignition on. Read off the parameters under vehicle communication to check the function of the steering wheel angle sensor module (SAS).

Is the function OK?

1. YES OKAY: Troubleshooting has been completed.
2. NO Refer to «Information»(ref-406816-S21527068542011070100000)

Identifying a control module in the CAN network

HINT: Use the wiring diagram to provide support when taking readings.

For general information about CAN-troubleshooting, see

1. INFORMATION/PRODUCTSPECIFICATIONS/Design and function/37/CAN-net.
2. See «General information about fault-tracing in the CAN network»(ref-441117-S34302411522011121500000)

HINT: DiCE can be used as fault detection tool if fault is suspected on the CAN-net that cannot be detected with normal troubleshooting. Interference, intermittent faults, faulty messages on the CAN-net (chattering control modules) etc. , are examples of such faults. The tool registers fault messages used on the CAN-net. Fault messages may be caused by short intermittent malfunctions on the CAN-net or by a control module sending fault messages. See tools:951 3010 (memory card) as well as associated TJ 20402.

If the load on the CAN network is too high, this may be due to a control module sending faulty messages on the CAN network (known as a disruptive control module). The fault may also be due to an intermittent short-circuit to supply voltage or ground in one of the CAN cables. This results in the control modules on the CAN network starting to send faulty messages. The faults can occur without a diagnostic trouble code (DTC) being stored by the control modules. The voltage can be measured between the CAN cables in order to check the load on the CAN network.

Note. It is not necessarily the control module(s) that stored the diagnostic trouble code (DTC) that is communicating faultily. Faulty messages can come from any control module in the same section of the CAN network. However, faulty communication in one network cannot affect the communication on the other network. In other words, faulty communication on the LS-CAN cannot disrupt communication on the HS-CAN and vice versa.

1. Ignition on.
2. Connect OBDII-Box (951 3015) to the diagnostics socket.

Check communication/load on CAN-net by measuring voltage between CAN-L and CAN-H. Measure voltage between the following connections on the OBDII-box/diagnostics socket.

1. #6 and #14. The average value of the voltage must be approximately 0. 6-1. 4 V. The voltage shall normally be between 0. 55 - 0. 90 V. A higher voltage may indicate increased traffic on the CAN-net. In case of fault in communication/too high traffic on the CAN-net, the voltage is considerably higher than the above stated values.

In order to identify which control module has faulty communication, cut the power supply to one control module at a time. Check the voltage in the CAN cables again. The easiest way to cut the power supply is to remove the fuse(s) for the relevant control module. Repeat until the voltage between the CAN wiring drops to the normal level.

Note. When connecting and disconnecting individual control modules, other diagnostic trouble codes (DTCs) may be stored in certain control modules.

HINT: When the suspected defective control module has been identified, connect and disconnect the supply voltage to the control module a number of times to verify that the malfunction appears and disappears. Switch off the ignition between each check.

Note. Do not cut the power to the central electronic module (CEM) unless it is the last control module left to check.

A control module that is communicating incorrectly must be replaced. See Repairing and installing/Removing, replacing and installing.

Note. After fault with control modules that interfere with communication, other control modules may remain in Limp-Home (that is, they work with reduced functionality) even when the ignition has been turned off and on a few times. For certain faults in the CAN-net where control modules have stopped communicating, it may help to disconnect/reconnect the battery to "restart" the control module/CAN-net.

Scheme 18

1. Continue Refer to «Verification»(ref-406816-S24535140582011070100000)

Verification

HINT: After rectifying a fault, a verification should be carried out.

Scheme 19

1. Reinstall the connectors, components etc.
2. Ignition on. NOTE: For certain faults in the CAN-net where control modules have stopped communicating, it may help to disconnect/reconnect the battery to "restart" the control module/CAN-net. Erase diagnostic trouble codes (DTCs) in all control modules. Ignition off. Ignition on. Start the vehicle. Allow the vehicle to run for 10 minutes. Read out the diagnostic trouble codes in the vehicle via the DIAGNOSTICS tab.

Does the diagnostic trouble code (DTC) for faulty communication return?

1. YES Refer to «Information»(ref-406816-S21527068542011070100000)
2. NO OKAY: Troubleshooting has been completed.

Scheme 20

1. Ignition off.
2. Disconnect the battery negative lead.
3. Connect OBDII-Box (951 3015) to the diagnostics socket. HINT: Use the wiring diagram to provide support when taking readings. For general information about CAN-troubleshooting, see: INFORMATION/PRODUCTSPECIFICATIONS/Design and function/37/CAN-net. See «General information about fault-tracing in the CAN network»(ref-441117-S34302411522011121500000) Checking for a short-circuit to ground Measure resistance between the following connections on the OBDII-box/diagnostics socket. #6 and #4 (ground). Measurement is shown in the figure. The resistance should be above 1 kohms. #14 and #4 (ground). The resistance should be above 1 kohms. If resistance is below 1 kohms this indicates short-circuiting between the CAN-line and ground. Checking for a short-circuit to voltage Measure resistance between the following connections on the OBDII-box/diagnostics socket. #6 and #16 (voltage). Measurement is shown in the figure. The resistance should be above 1 kohms. #14 and #16 (voltage). The resistance should be above 1 kohms. If resistance is below 1 kohms this indicates short-circuiting between the CAN-line and voltage cable. Twist the cable harness and wiggle connectors where they can be accessed along the cable harness during every measurement, and note if the resistance changes to detect intermittent short-circuits or open circuit. HINT: Part the CAN-net at suitable points to decide where a short-circuit may be found. NOTE: After fault with control modules that interfere with communication, other control modules may remain in Limp-Home (that is, they work with reduced functionality) even when the ignition has been turned off and on a few times. For certain faults in the CAN-net where control modules have stopped communicating, it may help to disconnect/reconnect the battery to "restart" the control module/CAN-net. Remedy wiring as necessary. Other information See «Battery, disconnecting»(ref-406866-S10988298012011070100000) See «Checking wiring and terminals»(ref-406811-S00386154732011070100000)

Was a fault detected?

1. YES Refer to «Verification»(ref-406816-S24535140582011070100000)
2. NO Refer to «Checking the traffic load on the CAN cables»(ref-406816-S25324129732011070100000)

Scheme 21

1. Connect the battery.
2. Ignition on.
3. Connect OBDII-Box (951 3015) to the diagnostics socket. HINT: Use the wiring diagram to provide support when taking readings. For general information about CAN-troubleshooting, see: INFORMATION/PRODUCTSPECIFICATIONS/Design and function/37/CAN-net. See «General information about fault-tracing in the CAN network»(ref-441117-S34302411522011121500000) In principle, the voltage measured in each cable in the CAN-net shall be the same at each control module in the network. This means that the voltage-drop in the cable for CAN-H and CAN-L, respectively, between the control modules should be very low. If there is a voltage-difference in the CAN-lines between the diagnostics socket/Central electronic module (CEM) and a control module due to, e. g. , contact resistance in a connector or branching, communication may be lost/interfered with. Check if there is voltage-drop in the cable for CAN-H and CAN-L between the diagnostics socket/Central electronic module (CEM) and the control module where there is problem with communication. Carry out the following: Measure voltage between the following connections on the OBDII-box/diagnostics socket. #6 and corresponding connection on relevant control module for CAN-H. The voltage shall be lower than 50 mV. #14 and corresponding connection on relevant control module for CAN-L. The voltage shall be lower than 50 mV. If voltage is too high, this indicates too high contact resistance in cable, connector, or branching. Check the circuit between the diagnostics socket and control module in question for contact resistance and oxidation. NOTE: After fault with control modules that interfere with communication, other control modules may remain in Limp-Home (that is, they work with reduced functionality) even when the ignition has been turned off and on a few times. For certain faults in the CAN-net where control modules have stopped communicating, it may help to disconnect/reconnect the battery to "restart" the control module/CAN-net. Remedy wiring as necessary. Other information See «Checking wiring and terminals»(ref-406811-S00386154732011070100000)

1. Continue Refer to «Verification»(ref-406816-S24535140582011070100000)

Fault-tracing information

The fault should have been detected and remedied. As this is not the case fault-tracing has failed.

Exit fault-tracing for this diagnostic trouble code (DTC) or make another attempt.

Checking the power supply and ground for the differential electronic module (DEM)

Check that the fuse for the control module is intact.

Checking the power supply and ground terminal for the differential electronic module (DEM).

Other information

1. See «Checking the supply voltage/ground terminal»(ref-406935-S25668520442011070100000)
2. For information about fuse and terminal numbers, see appropriate SYSTEM WIRING DIAGRAM article.
3. See «Contents»(ref-406811-S37635188302011070100000)

Scheme 22

Was a fault detected?

1. YES Refer to «Checking the differential electronic module (DEM)»(ref-406816-S24353021572011070100000)
2. NO Refer to «Checking communication with the differential electronic module (DEM)»(ref-406816-S11475089332011070100000)

Checking communication with the differential electronic module (DEM)

HINT: The CAN communication with the control module is probably OK if the control module ID can be read off. In that case the fault is probably intermittent and will then be more difficult to trace.

1. Try to communicate with the differential electronic module (DEM) by reading off the control module ID
2. Click on the symbol for VCT2000 to begin reading off

1. Continue Refer to «Signal missing»(ref-406816-S41240641292011070100000)

Checking the differential electronic module (DEM)

HINT: After carrying out the repair, check that the fault has been remedied.

1. Ignition off
2. Reconnect the connectors. Reinstall the components
3. Ignition on for at least 10 seconds. Read off the control module ID from the differential electronic module (DEM) by clicking on the VCT2000 symbol.

Could the control module ID be read off?

1. YES OKAY: Troubleshooting has been completed.
2. NO Refer to «Information»(ref-406816-S20850169952011070100000)

Checking resistance in CAN-net

1. Ignition off
2. Disconnect the battery negative lead
3. Connect OBDII-Box (951 3015) to the diagnostics socket. HINT: Use the wiring diagram to provide support when taking readings. For general information about CAN-troubleshooting, see: INFORMATION/PRODUCTSPECIFICATIONS/Design and function/37/CAN-net. See «General information about fault-tracing in the CAN network»(ref-441117-S34302411522011121500000) Measure resistance between the following connections on the OBDII-box/diagnostics socket. #6 and #14. The resistance should be approx. 55 - 65 ohms. If resistance is approx. 120 ohms, this indicates open circuit in the circuit so that only one terminating resistor (120 ohms) has been measured. If resistance is above 1 kohms this indicates open circuit/high contact resistance somewhere in the circuit. If resistance is below 55 ohms this indicates short-circuiting/contact resistance between the CAN-lines somewhere in the circuit. HINT: For HS-CAN ( ) the terminating resistors are located in Brake control module (BCM) and in Engine control module (ECM). Twist the cable harness and wiggle connectors where they can be accessed along the cable harness during every measurement, and note if the resistance changes to detect intermittent short-circuits or open circuit. NOTE: Resistance measurement measures only main lines in the CAN-net (in circuit where both terminating resistors are found), not branches to certain control modules. See appropriate SYSTEM WIRING DIAGRAM article. Open circuit on branching without a terminating resistor cannot be detected with this measurement. However, short-circuiting on a branch can be detected. To measure resistance in the CAN-net to control modules located in a branching of their own, the measurement shall be done against the CAN-net at that control module. The values shall be as above. NOTE: After fault with control modules that interfere with communication, other control modules may remain in Limp-Home (that is, they work with reduced functionality) even when the ignition has been turned off and on a few times. For certain faults in the CAN-net where control modules have stopped communicating, it may help to disconnect/reconnect the battery to "restart" the control module/CAN-net. Remedy wiring as necessary. Other information See «Battery, disconnecting»(ref-406866-S10988298012011070100000) See «Contents»(ref-406811-S37635188302011070100000)

Was a fault detected?

1. YES Refer to «Verification»(ref-406816-S29652936272011070100000)
2. NO Refer to «Checking short-circuiting to ground/voltage in CAN-net»(ref-406816-S14581262002011070100000)

Checking the traffic load on the CAN cables

1. Connect the battery
2. Ignition on.
3. Connect OBDII-Box (951 3015) to the diagnostics socket. HINT: Use the wiring diagram to provide support when taking readings. For general information about CAN-troubleshooting, see: INFORMATION/PRODUCTSPECIFICATIONS/Design and function/37/CAN-net. See «General information about fault-tracing in the CAN network»(ref-441117-S34302411522011121500000) Faults in the CAN network may be due to a control module sending faulty messages that disrupt normal communication. When messages are sent incorrectly, this results in a considerable increase in the amount of traffic on the CAN network. Check the load by measuring the average voltage value on the CAN cables in relation to ground. For further information, see appropriate SYSTEM WIRING DIAGRAM article. Measure voltage between the following connections on the OBDII-box/diagnostics socket. #6 and #4 (ground). The voltage should be approx:2,8 - 3,2 V. #14 and #4 (ground). The voltage should be approx:1,8 - 2,2 V. #6 and #14. The voltage shall be between approx. 0. 55-1. 4 V. The voltage shall normally be between 0. 55 - 0. 90 V. A higher voltage may indicate increased traffic on the CAN-net. In case of fault in communication/too high traffic on the CAN-net, the voltage is considerably higher than the above stated values. NOTE: After fault with control modules that interfere with communication, other control modules may remain in Limp-Home (that is, they work with reduced functionality) even when the ignition has been turned off and on a few times. For certain faults in the CAN-net where control modules have stopped communicating, it may help to disconnect/reconnect the battery to "restart" the control module/CAN-net. HINT: DiCE can be used as fault detection tool if fault is suspected on the CAN-net that cannot be detected with normal troubleshooting. Interference, intermittent faults, faulty messages on the CAN-net (chattering control modules) etc. , are examples of such faults. The tool registers fault messages used on the CAN-net. Fault messages may be caused by short intermittent malfunctions on the CAN-net or by a control module sending fault messages. See tools:951 3010 (memory card) as well as associated TJ 20402. Ignition on. Connect DiCE to the diagnostics socket. Note the blue LED-indicator. The indicator flashes to show detection of fault messages. NOTE: Certain interference may occur without any real fault Cable fault Shake the cables lightly and pull lightly on the connections during the check to locate any fault. Note the blue LED-indicator. "Chatting" control modules "Chatting" control modules may be difficult to find and troubleshooting may take time. Let the vehicle stand with DiCE connected for an extended time period. Afterwards, activate functions to provoke a malfunction. It may take up to several hours before the fault messages are sent. When the indicator starts to flash, remove the fuse for one control module at a time until the indicator stops flashing. When the indicator stops flashing, restore the fuse for the relevant control module and check that the indicator starts to flash again. Then it is likely that the problem is identified. Remedy wiring as necessary. Other information See «Battery, disconnecting»(ref-406866-S10988298012011070100000) See «Checking wiring and terminals»(ref-406811-S00386154732011070100000)

Was a fault detected?

1. YES Refer to «Identifying a control module in the CAN network»(ref-406816-S10930126382011070100000)
2. NO Refer to «Checking voltage-drop in cable for CAN-H and CAN-L, respectively»(ref-406816-S23018172032011070100000)

HINT: Use the wiring diagram to provide support when taking readings.

For general information about CAN-troubleshooting, see

1. INFORMATION/PRODUCTSPECIFICATIONS/Design and function/37/CAN-net.
2. See «General information about fault-tracing in the CAN network»(ref-441117-S34302411522011121500000)

HINT: DiCE can be used as fault detection tool if fault is suspected on the CAN-net that cannot be detected with normal troubleshooting. Interference, intermittent faults, faulty messages on the CAN-net (chattering control modules) etc. , are examples of such faults. The tool registers fault messages used on the CAN-net. Fault messages may be caused by short intermittent malfunctions on the CAN-net or by a control module sending fault messages. See tools:951 3010 (memory card) as well as associated TJ 20402.

If the load on the CAN network is too high, this may be due to a control module sending faulty messages on the CAN network (known as a disruptive control module). The fault may also be due to an intermittent short-circuit to supply voltage or ground in one of the CAN cables. This results in the control modules on the CAN network starting to send faulty messages. The faults can occur without a diagnostic trouble code (DTC) being stored by the control modules. The voltage can be measured between the CAN cables in order to check the load on the CAN network.

Note. It is not necessarily the control module(s) that stored the diagnostic trouble code (DTC) that is communicating faultily. Faulty messages can come from any control module in the same section of the CAN network. However, faulty communication in one network cannot affect the communication on the other network. In other words, faulty communication on the LS-CAN cannot disrupt communication on the HS-CAN and vice versa.

1. Ignition on.
2. Connect OBDII-Box (951 3015) to the diagnostics socket.

Check communication/load on CAN-net by measuring voltage between CAN-L and CAN-H. Measure voltage between the following connections on the OBDII-box/diagnostics socket.

1. #6 and #14. The average value of the voltage must be approximately 0. 6-1. 4 V. The voltage shall normally be between 0. 55 - 0. 90 V. A higher voltage may indicate increased traffic on the CAN-net. In case of fault in communication/too high traffic on the CAN-net, the voltage is considerably higher than the above stated values.

In order to identify which control module has faulty communication, cut the power supply to one control module at a time. Check the voltage in the CAN cables again. The easiest way to cut the power supply is to remove the fuse(s) for the relevant control module. Repeat until the voltage between the CAN wiring drops to the normal level.

Note. When connecting and disconnecting individual control modules, other diagnostic trouble codes (DTCs) may be stored in certain control modules.

HINT: When the suspected defective control module has been identified, connect and disconnect the supply voltage to the control module a number of times to verify that the malfunction appears and disappears. Switch off the ignition between each check.

Note. Do not cut the power to the central electronic module (CEM) unless it is the last control module left to check.

A control module that is communicating incorrectly must be replaced. See Repairing and installing/Removing, replacing and installing.

Note. After fault with control modules that interfere with communication, other control modules may remain in Limp-Home (that is, they work with reduced functionality) even when the ignition has been turned off and on a few times. For certain faults in the CAN-net where control modules have stopped communicating, it may help to disconnect/reconnect the battery to "restart" the control module/CAN-net.

1. Continue Refer to «Verification»(ref-406816-S29652936272011070100000)

HINT: After rectifying a fault, a verification should be carried out.

1. Reinstall the connectors, components etc.
2. Ignition on. NOTE: For certain faults in the CAN-net where control modules have stopped communicating, it may help to disconnect/reconnect the battery to "restart" the control module/CAN-net. Erase diagnostic trouble codes (DTCs) in all control modules. Ignition off. Ignition on. Start the vehicle. Allow the vehicle to run for 10 minutes. Read out the diagnostic trouble codes in the vehicle via the DIAGNOSTICS tab.

Does the diagnostic trouble code (DTC) for faulty communication return?

1. YES Refer to «Information»(ref-406816-S20850169952011070100000)
2. NO OKAY: Troubleshooting has been completed.

Checking short-circuiting to ground/voltage in CAN-net

1. Ignition off.
2. Disconnect the battery negative lead.
3. Connect OBDII-Box (951 3015) to the diagnostics socket. HINT: Use the wiring diagram to provide support when taking readings. For general information about CAN-troubleshooting, see: INFORMATION/PRODUCTSPECIFICATIONS/Design and function/37/CAN-net. See «General information about fault-tracing in the CAN network»(ref-441117-S34302411522011121500000) Checking for a short-circuit to ground Measure resistance between the following connections on the OBDII-box/diagnostics socket. #6 and #4 (ground). Measurement is shown in the figure. The resistance should be above 1 kohms. #14 and #4 (ground). The resistance should be above 1 kohms. If resistance is below 1 kohms this indicates short-circuiting between the CAN-line and ground. Checking for a short-circuit to voltage Measure resistance between the following connections on the OBDII-box/diagnostics socket. #6 and #16 (voltage). Measurement is shown in the figure. The resistance should be above 1 kohms. #14 and #16 (voltage). The resistance should be above 1 kohms. If resistance is below 1 kohms this indicates short-circuiting between the CAN-line and voltage cable. Twist the cable harness and wiggle connectors where they can be accessed along the cable harness during every measurement, and note if the resistance changes to detect intermittent short-circuits or open circuit. HINT: Part the CAN-net at suitable points to decide where a short-circuit may be found. NOTE: After fault with control modules that interfere with communication, other control modules may remain in Limp-Home (that is, they work with reduced functionality) even when the ignition has been turned off and on a few times. For certain faults in the CAN-net where control modules have stopped communicating, it may help to disconnect/reconnect the battery to "restart" the control module/CAN-net. Remedy wiring as necessary. Other information See «Battery, disconnecting»(ref-406866-S10988298012011070100000) See «Checking wiring and terminals»(ref-406811-S00386154732011070100000)

Was a fault detected?

1. YES Refer to «Verification»(ref-406816-S29652936272011070100000)
2. NO Refer to «Checking the traffic load on the CAN cables»(ref-406816-S01457282202011070100000)

Checking voltage-drop in cable for CAN-H and CAN-L, respectively

1. Connect the battery.
2. Ignition on.
3. Connect OBDII-Box (951 3015) to the diagnostics socket. HINT: Use the wiring diagram to provide support when taking readings. For general information about CAN-troubleshooting, see: INFORMATION/PRODUCTSPECIFICATIONS/Design and function/37/CAN-net. See «General information about fault-tracing in the CAN network»(ref-441117-S34302411522011121500000) In principle, the voltage measured in each cable in the CAN-net shall be the same at each control module in the network. This means that the voltage-drop in the cable for CAN-H and CAN-L, respectively, between the control modules should be very low. If there is a voltage-difference in the CAN-lines between the diagnostics socket/Central electronic module (CEM) and a control module due to, e. g. , contact resistance in a connector or branching, communication may be lost/interfered with. Check if there is voltage-drop in the cable for CAN-H and CAN-L between the diagnostics socket/Central electronic module (CEM) and the control module where there is problem with communication. Carry out the following: Measure voltage between the following connections on the OBDII-box/diagnostics socket. #6 and corresponding connection on relevant control module for CAN-H. The voltage shall be lower than 50 mV. #14 and corresponding connection on relevant control module for CAN-L. The voltage shall be lower than 50 mV. If voltage is too high, this indicates too high contact resistance in cable, connector, or branching. Check the circuit between the diagnostics socket and control module in question for contact resistance and oxidation. NOTE: After fault with control modules that interfere with communication, other control modules may remain in Limp-Home (that is, they work with reduced functionality) even when the ignition has been turned off and on a few times. For certain faults in the CAN-net where control modules have stopped communicating, it may help to disconnect/reconnect the battery to "restart" the control module/CAN-net. Remedy wiring as necessary. Other information See «Checking wiring and terminals»(ref-406811-S00386154732011070100000)

1. Continue Refer to «Verification»(ref-406816-S29652936272011070100000)

The fault should have been detected and remedied. As this is not the case fault-tracing has failed.

Exit fault-tracing for this diagnostic trouble code (DTC) or make another attempt.

Checking the power supply and ground for the transmission control module (TCM)

Check that the fuse for the control module is intact.

Check the power supply and ground for the transmission control module (TCM) as follows.

Remedy as necessary.

Other information

1. See «Checking the power supply and ground terminals»(ref-406842-S41352848432011070100000)
2. For information about fuse and terminal numbers, see appropriate SYSTEM WIRING DIAGRAM article.
3. See «Contents»(ref-406811-S37635188302011070100000)

Was a fault detected?

1. YES Refer to «Checking the transmission control module (TCM)»(ref-406816-S41904591822011070100000)
2. NO Refer to «Checking the communication with the transmission control module (TCM)»(ref-406816-S28375404132011070100000)

Checking the communication with the transmission control module (TCM)

HINT: The CAN communication with the control module is probably OK if the control module ID can be read off. In that case the fault is probably intermittent and will then be more difficult to trace.

1. Try to communicate with the transmission control module (TCM) by reading off the control module ID
2. Click on the symbol for VCT2000 to begin reading off

1. Continue Refer to «Signal missing»(ref-406816-S41965486842011070100000)

Checking the transmission control module (TCM)

HINT: After carrying out the repair, check that the fault has been remedied.

1. Ignition off
2. Reconnect the connectors. Reinstall the components
3. Ignition on for at least 10 seconds. Read off the control module ID from the transmission control module (TCM) by clicking on the VCT2000 symbol.

Could the control module ID be read off?

1. YES OKAY: Troubleshooting has been completed.
2. NO Refer to «Information»(ref-406816-S05834560172011070100000)

1. Ignition off
2. Disconnect the battery negative lead
3. Connect OBDII-Box (951 3015) to the diagnostics socket. HINT: Use the wiring diagram to provide support when taking readings. For general information about CAN-troubleshooting, see: INFORMATION/PRODUCTSPECIFICATIONS/Design and function/37/CAN-net. See «General information about fault-tracing in the CAN network»(ref-441117-S34302411522011121500000) Measure resistance between the following connections on the OBDII-box/diagnostics socket. #6 and #14. The resistance should be approx. 55 - 65 ohms. If resistance is approx. 120 ohms, this indicates open circuit in the circuit so that only one terminating resistor (120 ohms) has been measured. If resistance is above 1 kohms this indicates open circuit/high contact resistance somewhere in the circuit. If resistance is below 55 ohms this indicates short-circuiting/contact resistance between the CAN-lines somewhere in the circuit. HINT: For HS-CAN ( ) the terminating resistors are located in Brake control module (BCM) and in Engine control module (ECM). Twist the cable harness and wiggle connectors where they can be accessed along the cable harness during every measurement, and note if the resistance changes to detect intermittent short-circuits or open circuit. NOTE: Resistance measurement measures only main lines in the CAN-net (in circuit where both terminating resistors are found), not branches to certain control modules. See appropriate SYSTEM WIRING DIAGRAM article. Open circuit on branching without a terminating resistor cannot be detected with this measurement. However, short-circuiting on a branch can be detected. To measure resistance in the CAN-net to control modules located in a branching of their own, the measurement shall be done against the CAN-net at that control module. The values shall be as above. NOTE: After fault with control modules that interfere with communication, other control modules may remain in Limp-Home (that is, they work with reduced functionality) even when the ignition has been turned off and on a few times. For certain faults in the CAN-net where control modules have stopped communicating, it may help to disconnect/reconnect the battery to "restart" the control module/CAN-net. Remedy wiring as necessary. Other information See «Battery, disconnecting»(ref-406866-S10988298012011070100000) See «Contents»(ref-406811-S37635188302011070100000)

Was a fault detected?

1. YES Refer to «Verification»(ref-406816-S16525795292011070100000)
2. NO Refer to «Checking short-circuiting to ground/voltage in CAN-net»(ref-406816-S01325632912011070100000)

1. Connect the battery
2. Ignition on.
3. Connect OBDII-Box (951 3015) to the diagnostics socket. HINT: Use the wiring diagram to provide support when taking readings. For general information about CAN-troubleshooting, see: INFORMATION/PRODUCTSPECIFICATIONS/Design and function/37/CAN-net. See «General information about fault-tracing in the CAN network»(ref-441117-S34302411522011121500000) Faults in the CAN network may be due to a control module sending faulty messages that disrupt normal communication. When messages are sent incorrectly, this results in a considerable increase in the amount of traffic on the CAN network. Check the load by measuring the average voltage value on the CAN cables in relation to ground. For further information, see appropriate SYSTEM WIRING DIAGRAM article. Measure voltage between the following connections on the OBDII-box/diagnostics socket. #6 and #4 (ground). The voltage should be approx:2,8 - 3,2 V. #14 and #4 (ground). The voltage should be approx:1,8 - 2,2 V. #6 and #14. The voltage shall be between approx. 0. 55-1. 4 V. The voltage shall normally be between 0. 55 - 0. 90 V. A higher voltage may indicate increased traffic on the CAN-net. In case of fault in communication/too high traffic on the CAN-net, the voltage is considerably higher than the above stated values. NOTE: After fault with control modules that interfere with communication, other control modules may remain in Limp-Home (that is, they work with reduced functionality) even when the ignition has been turned off and on a few times. For certain faults in the CAN-net where control modules have stopped communicating, it may help to disconnect/reconnect the battery to "restart" the control module/CAN-net. HINT: DiCE can be used as fault detection tool if fault is suspected on the CAN-net that cannot be detected with normal troubleshooting. Interference, intermittent faults, faulty messages on the CAN-net (chattering control modules) etc. , are examples of such faults. The tool registers fault messages used on the CAN-net. Fault messages may be caused by short intermittent malfunctions on the CAN-net or by a control module sending fault messages. See tools:951 3010 (memory card) as well as associated TJ 20402. Ignition on. Connect DiCE to the diagnostics socket. Note the blue LED-indicator. The indicator flashes to show detection of fault messages. NOTE: Certain interference may occur without any real fault Cable fault Shake the cables lightly and pull lightly on the connections during the check to locate any fault. Note the blue LED-indicator. "Chatting" control modules "Chatting" control modules may be difficult to find and troubleshooting may take time. Let the vehicle stand with DiCE connected for an extended time period. Afterwards, activate functions to provoke a malfunction. It may take up to several hours before the fault messages are sent. When the indicator starts to flash, remove the fuse for one control module at a time until the indicator stops flashing. When the indicator stops flashing, restore the fuse for the relevant control module and check that the indicator starts to flash again. Then it is likely that the problem is identified. Remedy wiring as necessary. Other information See «Battery, disconnecting»(ref-406866-S10988298012011070100000) See «Checking wiring and terminals»(ref-406811-S00386154732011070100000)

Was a fault detected?

1. YES Refer to «Identifying a control module in the CAN network»(ref-406816-S23431446752011070100000)
2. NO Refer to «Checking voltage-drop in cable for CAN-H and CAN-L, respectively»(ref-406816-S07507220642011070100000)

HINT: Use the wiring diagram to provide support when taking readings.

For general information about CAN-troubleshooting, see

1. INFORMATION/PRODUCTSPECIFICATIONS/Design and function/37/CAN-net.
2. See «General information about fault-tracing in the CAN network»(ref-441117-S34302411522011121500000)

HINT: DiCE can be used as fault detection tool if fault is suspected on the CAN-net that cannot be detected with normal troubleshooting. Interference, intermittent faults, faulty messages on the CAN-net (chattering control modules) etc. , are examples of such faults. The tool registers fault messages used on the CAN-net. Fault messages may be caused by short intermittent malfunctions on the CAN-net or by a control module sending fault messages. See tools:951 3010 (memory card) as well as associated TJ 20402.

If the load on the CAN network is too high, this may be due to a control module sending faulty messages on the CAN network (known as a disruptive control module). The fault may also be due to an intermittent short-circuit to supply voltage or ground in one of the CAN cables. This results in the control modules on the CAN network starting to send faulty messages. The faults can occur without a diagnostic trouble code (DTC) being stored by the control modules. The voltage can be measured between the CAN cables in order to check the load on the CAN network.

Note. It is not necessarily the control module(s) that stored the diagnostic trouble code (DTC) that is communicating faultily. Faulty messages can come from any control module in the same section of the CAN network. However, faulty communication in one network cannot affect the communication on the other network. In other words, faulty communication on the LS-CAN cannot disrupt communication on the HS-CAN and vice versa.

1. Ignition on.
2. Connect OBDII-Box (951 3015) to the diagnostics socket.

Check communication/load on CAN-net by measuring voltage between CAN-L and CAN-H. Measure voltage between the following connections on the OBDII-box/diagnostics socket.

1. #6 and #14. The average value of the voltage must be approximately 0. 6-1. 4 V. The voltage shall normally be between 0. 55 - 0. 90 V. A higher voltage may indicate increased traffic on the CAN-net. In case of fault in communication/too high traffic on the CAN-net, the voltage is considerably higher than the above stated values.

In order to identify which control module has faulty communication, cut the power supply to one control module at a time. Check the voltage in the CAN cables again. The easiest way to cut the power supply is to remove the fuse(s) for the relevant control module. Repeat until the voltage between the CAN wiring drops to the normal level.

Note. When connecting and disconnecting individual control modules, other diagnostic trouble codes (DTCs) may be stored in certain control modules.

HINT: When the suspected defective control module has been identified, connect and disconnect the supply voltage to the control module a number of times to verify that the malfunction appears and disappears. Switch off the ignition between each check.

Note. Do not cut the power to the central electronic module (CEM) unless it is the last control module left to check.

A control module that is communicating incorrectly must be replaced. See Repairing and installing/Removing, replacing and installing.

Note. After fault with control modules that interfere with communication, other control modules may remain in Limp-Home (that is, they work with reduced functionality) even when the ignition has been turned off and on a few times. For certain faults in the CAN-net where control modules have stopped communicating, it may help to disconnect/reconnect the battery to "restart" the control module/CAN-net.

1. Continue Refer to «Verification»(ref-406816-S16525795292011070100000)

HINT: After rectifying a fault, a verification should be carried out.

1. Reinstall the connectors, components etc.
2. Ignition on. NOTE: For certain faults in the CAN-net where control modules have stopped communicating, it may help to disconnect/reconnect the battery to "restart" the control module/CAN-net. Erase diagnostic trouble codes (DTCs) in all control modules. Ignition off. Ignition on. Start the vehicle. Allow the vehicle to run for 10 minutes. Read out the diagnostic trouble codes in the vehicle via the DIAGNOSTICS tab.

Does the diagnostic trouble code (DTC) for faulty communication return?

1. YES Refer to «Information»(ref-406816-S05834560172011070100000)
2. NO OKAY: Troubleshooting has been completed.

1. Ignition off.
2. Disconnect the battery negative lead.
3. Connect OBDII-Box (951 3015) to the diagnostics socket. HINT: Use the wiring diagram to provide support when taking readings. For general information about CAN-troubleshooting, see: INFORMATION/PRODUCTSPECIFICATIONS/Design and function/37/CAN-net. See «General information about fault-tracing in the CAN network»(ref-441117-S34302411522011121500000) Checking for a short-circuit to ground Measure resistance between the following connections on the OBDII-box/diagnostics socket. #6 and #4 (ground). Measurement is shown in the figure. The resistance should be above 1 kohms. #14 and #4 (ground). The resistance should be above 1 kohms. If resistance is below 1 kohms this indicates short-circuiting between the CAN-line and ground. Checking for a short-circuit to voltage Measure resistance between the following connections on the OBDII-box/diagnostics socket. #6 and #16 (voltage). Measurement is shown in the figure. The resistance should be above 1 kohms. #14 and #16 (voltage). The resistance should be above 1 kohms. If resistance is below 1 kohms this indicates short-circuiting between the CAN-line and voltage cable. Twist the cable harness and wiggle connectors where they can be accessed along the cable harness during every measurement, and note if the resistance changes to detect intermittent short-circuits or open circuit. HINT: Part the CAN-net at suitable points to decide where a short-circuit may be found. NOTE: After fault with control modules that interfere with communication, other control modules may remain in Limp-Home (that is, they work with reduced functionality) even when the ignition has been turned off and on a few times. For certain faults in the CAN-net where control modules have stopped communicating, it may help to disconnect/reconnect the battery to "restart" the control module/CAN-net. Remedy wiring as necessary. Other information See «Battery, disconnecting»(ref-406866-S10988298012011070100000) See «Checking wiring and terminals»(ref-406811-S00386154732011070100000)

Was a fault detected?

1. YES Refer to «Verification»(ref-406816-S16525795292011070100000)
2. NO Refer to «Checking the traffic load on the CAN cables»(ref-406816-S29222329892011070100000)

1. Connect the battery.
2. Ignition on.
3. Connect OBDII-Box (951 3015) to the diagnostics socket. HINT: Use the wiring diagram to provide support when taking readings. For general information about CAN-troubleshooting, see: INFORMATION/PRODUCTSPECIFICATIONS/Design and function/37/CAN-net. See «General information about fault-tracing in the CAN network»(ref-441117-S34302411522011121500000) In principle, the voltage measured in each cable in the CAN-net shall be the same at each control module in the network. This means that the voltage-drop in the cable for CAN-H and CAN-L, respectively, between the control modules should be very low. If there is a voltage-difference in the CAN-lines between the diagnostics socket/Central electronic module (CEM) and a control module due to, e. g. , contact resistance in a connector or branching, communication may be lost/interfered with. Check if there is voltage-drop in the cable for CAN-H and CAN-L between the diagnostics socket/Central electronic module (CEM) and the control module where there is problem with communication. Carry out the following: Measure voltage between the following connections on the OBDII-box/diagnostics socket. #6 and corresponding connection on relevant control module for CAN-H. The voltage shall be lower than 50 mV. #14 and corresponding connection on relevant control module for CAN-L. The voltage shall be lower than 50 mV. If voltage is too high, this indicates too high contact resistance in cable, connector, or branching. Check the circuit between the diagnostics socket and control module in question for contact resistance and oxidation. NOTE: After fault with control modules that interfere with communication, other control modules may remain in Limp-Home (that is, they work with reduced functionality) even when the ignition has been turned off and on a few times. For certain faults in the CAN-net where control modules have stopped communicating, it may help to disconnect/reconnect the battery to "restart" the control module/CAN-net. Remedy wiring as necessary. Other information See «Checking wiring and terminals»(ref-406811-S00386154732011070100000)

1. Continue Refer to «Verification»(ref-406816-S16525795292011070100000)

The fault should have been detected and remedied. As this is not the case fault-tracing has failed.

Exit fault-tracing for this diagnostic trouble code (DTC) or make another attempt.

Checking the power supply and ground

Check that the fuse for the control module is intact.

Check the power supply and grounding point of the headlight control module (HCM).

Other information

1. See «Checking the power supply and ground terminal»(ref-406823-S36499356462011070100000)
2. For information about fuse and terminal numbers, see appropriate SYSTEM WIRING DIAGRAM article.
3. See «Checking wiring and terminals»(ref-406811-S00386154732011070100000)

Scheme 23

Was a fault detected?

1. YES Refer to «Checking headlight control module (HCM)»(ref-406816-S32871403772011070100000)
2. NO Refer to «Checking communication with the headlight control module (HCM)»(ref-406816-S10730959822011070100000)

Checking communication with the headlight control module (HCM)

HINT: The CAN communication with the control module is probably OK if the control module ID can be read off. In that case the fault is probably intermittent and will then be more difficult to trace.

1. Ignition on.
2. Try to communicate with the headlight control module (HCM) by reading off the control module ID.
3. Click the symbol for VCT2000 to begin reading off.

Scheme 24

1. Continue Refer to «Signal missing»(ref-406816-S35667513152011070100000)

Checking headlight control module (HCM)

HINT: After carrying out the repair, check that the fault has been remedied.

1. Ignition off.
2. Reinstall the connectors, components etc.
3. Ignition on.

Obtain the ID of the headlight control module (HCM) by clicking on the VCT2000 symbol.

Could the control module ID be read off?

1. YES OKAY: Troubleshooting has been completed.
2. NO Refer to «Information»(ref-406816-S15011774442011070100000)

1. Ignition off
2. Disconnect the battery negative lead
3. Connect OBDII-Box (951 3015) to the diagnostics socket. HINT: Use the wiring diagram to provide support when taking readings. For general information about CAN-troubleshooting, see: INFORMATION/PRODUCTSPECIFICATIONS/Design and function/37/CAN-net. See «General information about fault-tracing in the CAN network»(ref-441117-S34302411522011121500000) Measure resistance between the following connections on the OBDII-box/diagnostics socket. #6 and #14. The resistance should be approx. 55 - 65 ohms. If resistance is approx. 120 ohms, this indicates open circuit in the circuit so that only one terminating resistor (120 ohms) has been measured. If resistance is above 1 kohms this indicates open circuit/high contact resistance somewhere in the circuit. If resistance is below 55 ohms this indicates short-circuiting/contact resistance between the CAN-lines somewhere in the circuit. HINT: For HS-CAN ( ) the terminating resistors are located in Brake control module (BCM) and in Engine control module (ECM). Twist the cable harness and wiggle connectors where they can be accessed along the cable harness during every measurement, and note if the resistance changes to detect intermittent short-circuits or open circuit. NOTE: Resistance measurement measures only main lines in the CAN-net (in circuit where both terminating resistors are found), not branches to certain control modules. See appropriate SYSTEM WIRING DIAGRAM article. Open circuit on branching without a terminating resistor cannot be detected with this measurement. However, short-circuiting on a branch can be detected. To measure resistance in the CAN-net to control modules located in a branching of their own, the measurement shall be done against the CAN-net at that control module. The values shall be as above. NOTE: After fault with control modules that interfere with communication, other control modules may remain in Limp-Home (that is, they work with reduced functionality) even when the ignition has been turned off and on a few times. For certain faults in the CAN-net where control modules have stopped communicating, it may help to disconnect/reconnect the battery to "restart" the control module/CAN-net. Remedy wiring as necessary. Other information See «Battery, disconnecting»(ref-406866-S10988298012011070100000) See «Contents»(ref-406811-S37635188302011070100000)

Was a fault detected?

1. YES Refer to «Verification»(ref-406816-S33879972722011070100000)
2. NO Refer to «Checking short-circuiting to ground/voltage in CAN-net»(ref-406816-S42300219482011070100000)

1. Connect the battery
2. Ignition on.
3. Connect OBDII-Box (951 3015) to the diagnostics socket. HINT: Use the wiring diagram to provide support when taking readings. For general information about CAN-troubleshooting, see: INFORMATION/PRODUCTSPECIFICATIONS/Design and function/37/CAN-net. See «General information about fault-tracing in the CAN network»(ref-441117-S34302411522011121500000) Faults in the CAN network may be due to a control module sending faulty messages that disrupt normal communication. When messages are sent incorrectly, this results in a considerable increase in the amount of traffic on the CAN network. Check the load by measuring the average voltage value on the CAN cables in relation to ground. For further information, see appropriate SYSTEM WIRING DIAGRAM article. Measure voltage between the following connections on the OBDII-box/diagnostics socket. #6 and #4 (ground). The voltage should be approx:2,8 - 3,2 V. #14 and #4 (ground). The voltage should be approx:1,8 - 2,2 V. #6 and #14. The voltage shall be between approx. 0. 55-1. 4 V. The voltage shall normally be between 0. 55 - 0. 90 V. A higher voltage may indicate increased traffic on the CAN-net. In case of fault in communication/too high traffic on the CAN-net, the voltage is considerably higher than the above stated values. NOTE: After fault with control modules that interfere with communication, other control modules may remain in Limp-Home (that is, they work with reduced functionality) even when the ignition has been turned off and on a few times. For certain faults in the CAN-net where control modules have stopped communicating, it may help to disconnect/reconnect the battery to "restart" the control module/CAN-net. HINT: DiCE can be used as fault detection tool if fault is suspected on the CAN-net that cannot be detected with normal troubleshooting. Interference, intermittent faults, faulty messages on the CAN-net (chattering control modules) etc. , are examples of such faults. The tool registers fault messages used on the CAN-net. Fault messages may be caused by short intermittent malfunctions on the CAN-net or by a control module sending fault messages. See tools:951 3010 (memory card) as well as associated TJ 20402. Ignition on. Connect DiCE to the diagnostics socket. Note the blue LED-indicator. The indicator flashes to show detection of fault messages. NOTE: Certain interference may occur without any real fault Cable fault Shake the cables lightly and pull lightly on the connections during the check to locate any fault. Note the blue LED-indicator. "Chatting" control modules "Chatting" control modules may be difficult to find and troubleshooting may take time. Let the vehicle stand with DiCE connected for an extended time period. Afterwards, activate functions to provoke a malfunction. It may take up to several hours before the fault messages are sent. When the indicator starts to flash, remove the fuse for one control module at a time until the indicator stops flashing. When the indicator stops flashing, restore the fuse for the relevant control module and check that the indicator starts to flash again. Then it is likely that the problem is identified. Remedy wiring as necessary. Other information See «Battery, disconnecting»(ref-406866-S10988298012011070100000) See «Checking wiring and terminals»(ref-406811-S00386154732011070100000)

Was a fault detected?

1. YES Refer to «Identifying a control module in the CAN network»(ref-406816-S37434911902011070100000)
2. NO Refer to «Checking voltage-drop in cable for CAN-H and CAN-L, respectively»(ref-406816-S19932679552011070100000)

HINT: Use the wiring diagram to provide support when taking readings.

For general information about CAN-troubleshooting, see

1. INFORMATION/PRODUCTSPECIFICATIONS/Design and function/37/CAN-net.
2. See «General information about fault-tracing in the CAN network»(ref-441117-S34302411522011121500000)

HINT: DiCE can be used as fault detection tool if fault is suspected on the CAN-net that cannot be detected with normal troubleshooting. Interference, intermittent faults, faulty messages on the CAN-net (chattering control modules) etc. , are examples of such faults. The tool registers fault messages used on the CAN-net. Fault messages may be caused by short intermittent malfunctions on the CAN-net or by a control module sending fault messages. See tools:951 3010 (memory card) as well as associated TJ 20402.

If the load on the CAN network is too high, this may be due to a control module sending faulty messages on the CAN network (known as a disruptive control module). The fault may also be due to an intermittent short-circuit to supply voltage or ground in one of the CAN cables. This results in the control modules on the CAN network starting to send faulty messages. The faults can occur without a diagnostic trouble code (DTC) being stored by the control modules. The voltage can be measured between the CAN cables in order to check the load on the CAN network.

Note. It is not necessarily the control module(s) that stored the diagnostic trouble code (DTC) that is communicating faultily. Faulty messages can come from any control module in the same section of the CAN network. However, faulty communication in one network cannot affect the communication on the other network. In other words, faulty communication on the LS-CAN cannot disrupt communication on the HS-CAN and vice versa.

1. Ignition on.
2. Connect OBDII-Box (951 3015) to the diagnostics socket.

Check communication/load on CAN-net by measuring voltage between CAN-L and CAN-H. Measure voltage between the following connections on the OBDII-box/diagnostics socket.

1. #6 and #14. The average value of the voltage must be approximately 0. 6-1. 4 V. The voltage shall normally be between 0. 55 - 0. 90 V. A higher voltage may indicate increased traffic on the CAN-net. In case of fault in communication/too high traffic on the CAN-net, the voltage is considerably higher than the above stated values.

In order to identify which control module has faulty communication, cut the power supply to one control module at a time. Check the voltage in the CAN cables again. The easiest way to cut the power supply is to remove the fuse(s) for the relevant control module. Repeat until the voltage between the CAN wiring drops to the normal level.

Note. When connecting and disconnecting individual control modules, other diagnostic trouble codes (DTCs) may be stored in certain control modules.

HINT: When the suspected defective control module has been identified, connect and disconnect the supply voltage to the control module a number of times to verify that the malfunction appears and disappears. Switch off the ignition between each check.

Note. Do not cut the power to the central electronic module (CEM) unless it is the last control module left to check.

A control module that is communicating incorrectly must be replaced. See Repairing and installing/Removing, replacing and installing.

Note. After fault with control modules that interfere with communication, other control modules may remain in Limp-Home (that is, they work with reduced functionality) even when the ignition has been turned off and on a few times. For certain faults in the CAN-net where control modules have stopped communicating, it may help to disconnect/reconnect the battery to "restart" the control module/CAN-net.

1. Continue Refer to «Verification»(ref-406816-S33879972722011070100000)

HINT: After rectifying a fault, a verification should be carried out.

1. Reinstall the connectors, components etc.
2. Ignition on. NOTE: For certain faults in the CAN-net where control modules have stopped communicating, it may help to disconnect/reconnect the battery to "restart" the control module/CAN-net. Erase diagnostic trouble codes (DTCs) in all control modules. Ignition off. Ignition on. Start the vehicle. Allow the vehicle to run for 10 minutes. Read out the diagnostic trouble codes in the vehicle via the DIAGNOSTICS tab.

Does the diagnostic trouble code (DTC) for faulty communication return?

1. YES Refer to «Information»(ref-406816-S15011774442011070100000)
2. NO OKAY: Troubleshooting has been completed.

1. Ignition off.
2. Disconnect the battery negative lead.
3. Connect OBDII-Box (951 3015) to the diagnostics socket. HINT: Use the wiring diagram to provide support when taking readings. For general information about CAN-troubleshooting, see: INFORMATION/PRODUCTSPECIFICATIONS/Design and function/37/CAN-net. See «General information about fault-tracing in the CAN network»(ref-441117-S34302411522011121500000) Checking for a short-circuit to ground Measure resistance between the following connections on the OBDII-box/diagnostics socket. #6 and #4 (ground). Measurement is shown in the figure. The resistance should be above 1 kohms. #14 and #4 (ground). The resistance should be above 1 kohms. If resistance is below 1 kohms this indicates short-circuiting between the CAN-line and ground. Checking for a short-circuit to voltage Measure resistance between the following connections on the OBDII-box/diagnostics socket. #6 and #16 (voltage). Measurement is shown in the figure. The resistance should be above 1 kohms. #14 and #16 (voltage). The resistance should be above 1 kohms. If resistance is below 1 kohms this indicates short-circuiting between the CAN-line and voltage cable. Twist the cable harness and wiggle connectors where they can be accessed along the cable harness during every measurement, and note if the resistance changes to detect intermittent short-circuits or open circuit. HINT: Part the CAN-net at suitable points to decide where a short-circuit may be found. NOTE: After fault with control modules that interfere with communication, other control modules may remain in Limp-Home (that is, they work with reduced functionality) even when the ignition has been turned off and on a few times. For certain faults in the CAN-net where control modules have stopped communicating, it may help to disconnect/reconnect the battery to "restart" the control module/CAN-net. Remedy wiring as necessary. Other information See «Battery, disconnecting»(ref-406866-S10988298012011070100000) See «Checking wiring and terminals»(ref-406811-S00386154732011070100000)

Was a fault detected?

1. YES Refer to «Verification»(ref-406816-S33879972722011070100000)
2. NO Refer to «Checking the traffic load on the CAN cables»(ref-406816-S42060334442011070100000)

1. Connect the battery.
2. Ignition on.
3. Connect OBDII-Box (951 3015) to the diagnostics socket. HINT: Use the wiring diagram to provide support when taking readings. For general information about CAN-troubleshooting, see: INFORMATION/PRODUCTSPECIFICATIONS/Design and function/37/CAN-net. See «General information about fault-tracing in the CAN network»(ref-441117-S34302411522011121500000) In principle, the voltage measured in each cable in the CAN-net shall be the same at each control module in the network. This means that the voltage-drop in the cable for CAN-H and CAN-L, respectively, between the control modules should be very low. If there is a voltage-difference in the CAN-lines between the diagnostics socket/Central electronic module (CEM) and a control module due to, e. g. , contact resistance in a connector or branching, communication may be lost/interfered with. Check if there is voltage-drop in the cable for CAN-H and CAN-L between the diagnostics socket/Central electronic module (CEM) and the control module where there is problem with communication. Carry out the following: Measure voltage between the following connections on the OBDII-box/diagnostics socket. #6 and corresponding connection on relevant control module for CAN-H. The voltage shall be lower than 50 mV. #14 and corresponding connection on relevant control module for CAN-L. The voltage shall be lower than 50 mV. If voltage is too high, this indicates too high contact resistance in cable, connector, or branching. Check the circuit between the diagnostics socket and control module in question for contact resistance and oxidation. NOTE: After fault with control modules that interfere with communication, other control modules may remain in Limp-Home (that is, they work with reduced functionality) even when the ignition has been turned off and on a few times. For certain faults in the CAN-net where control modules have stopped communicating, it may help to disconnect/reconnect the battery to "restart" the control module/CAN-net. Remedy wiring as necessary. Other information See «Checking wiring and terminals»(ref-406811-S00386154732011070100000)

1. Continue Refer to «Verification»(ref-406816-S33879972722011070100000)

The fault should have been detected and remedied. As this is not the case fault-tracing has failed.

Exit fault-tracing for this diagnostic trouble code (DTC) or make another attempt.