Central Electronic Module (Cem) & Accessory Electronic Module (Aem) Diagnostic Trouble Codes: Other Volvo V70 II

Checking the power supply and ground on the Accessory Electronic Module (AEM)

Check the power supply to the Accessory Electronic Module (AEM). Check between the breakout box terminals for the power supply (#52) and ground (#51). The voltage must be at least battery voltage minus 3 V.

Check the control module connector. Check for contact resistance and oxidation. Check for loose connections. Check for damage carefully.

Check the wiring between the Accessory Electronic Module (AEM) (breakout box for ground terminal #51) and ground. Check for an open-circuit.

Remedy as necessary.

Other information

1. To connect the breakout box, see «Connecting the breakout box. Accessory electronic module»(ref-406825-S01828266742011070100000)
2. To access or replace the Accessory Electronic Module (AEM) and connector, see «Accessory electronic module (AEM), replacing»(ref-441132-S40916385662011121500000)
3. For information about signals, see «Signal description. Accessory electronic module (AEM)»(ref-406827-S35003813772011070100000)
4. To fault-trace wiring and terminals see «Contents»(ref-406811-S37635188302011070100000)
5. For information about the fuses and ground terminals, see the appropriate SYSTEM WIRING DIAGRAM article.

Scheme 296

1. Continue Refer to «Verification»(ref-406910-S14320849902011070100000)

Verification

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

Scheme 297

Scheme 298

Scheme 299

1. Ignition off
2. Reconnect the components, connectors etc.
3. Ignition on. Read off the power supply for the accessory electronic module by clicking on the VCT2000 symbol. The voltage must be at least battery voltage minus three volts.

Is the voltage OK?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «Information»(ref-406910-S08389297652011070100000)

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.

Signal too low

See Signal too low

Replacing the Accessory Electronic Module (AEM)

The Accessory Electronic Module (AEM) has registered an internal fault.

If the fault is intermittent, it has been registered previously but is no longer present. Intermittent faults can occur for a number of different reasons. The fault is evaluated depending on how it occurs. Replace the Accessory Electronic Module (AEM) if the fault recurs.

Replace the Accessory Electronic Module (AEM) if the fault is permanent. See Accessory electronic module (AEM), replacing .

Remedy as necessary.

Scheme 300

1. Continue OKAY: Troubleshooting has been completed.

Internal fault

See Internal fault

Reloading the software in the control module

The control module has registered an internal fault in the software.

Remedy the fault by reloading the software. First download the software for the accessory electronic module. Then download the software for the connected accessories.

1. Continue OKAY: Troubleshooting has been completed.

See Internal fault

The control module has registered an internal fault in the software.

Remedy the fault by reloading the software. First download the software for the accessory electronic module. Then download the software for the connected accessories.

1. Continue OKAY: Troubleshooting has been completed.

See Internal fault

The Accessory Electronic Module (AEM) has registered an internal fault.

If the fault is intermittent, it has been registered previously but is no longer present. Intermittent faults can occur for a number of different reasons. The fault is evaluated depending on how it occurs. Replace the Accessory Electronic Module (AEM) if the fault recurs.

Replace the Accessory Electronic Module (AEM) if the fault is permanent. See Accessory electronic module (AEM), replacing .

Remedy as necessary.

1. Continue OKAY: Troubleshooting has been completed.

See Internal fault

The Accessory Electronic Module (AEM) has registered an internal fault.

If the fault is intermittent, it has been registered previously but is no longer present. Intermittent faults can occur for a number of different reasons. The fault is evaluated depending on how it occurs. Replace the Accessory Electronic Module (AEM) if the fault recurs.

Replace the Accessory Electronic Module (AEM) if the fault is permanent. See Accessory electronic module (AEM), replacing .

Remedy as necessary.

1. Continue OKAY: Troubleshooting has been completed.

See Internal fault

The Accessory Electronic Module (AEM) has registered an internal fault.

If the fault is intermittent, it has been registered previously but is no longer present. Intermittent faults can occur for a number of different reasons. The fault is evaluated depending on how it occurs. Replace the Accessory Electronic Module (AEM) if the fault recurs.

Replace the Accessory Electronic Module (AEM) if the fault is permanent. See Accessory electronic module (AEM), replacing .

Remedy as necessary.

1. Continue OKAY: Troubleshooting has been completed.

See Internal fault

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

1. Ignition off
2. Reconnect the components, connectors etc.
3. Ignition on. Check the function of the back-up (reversing) warning system by clicking on the VCT2000 symbol.

Does the system function?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «Information»(ref-406910-S04923134612011070100000)

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.

See Signal too low

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

1. Ignition off
2. Reconnect the components, connectors etc.
3. Ignition on. Check the function of the back-up (reversing) warning system by clicking on the VCT2000 symbol.

Does the system function?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «Information»(ref-406910-S13638196292011070100000)

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.

Signal too high

See Signal too high

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

1. Ignition off
2. Reconnect the components, connectors etc.
3. Ignition on. Check the function of the back-up (reversing) warning system by clicking on the VCT2000 symbol.

Does the system function?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «Information»(ref-406910-S29315003702011070100000)

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.

See Signal too low

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

1. Ignition off
2. Reconnect the components, connectors etc.
3. Ignition on. Check the function of the back-up (reversing) warning system by clicking on the VCT2000 symbol.

Does the system function?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «Information»(ref-406910-S34367427802011070100000)

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.

See Signal too high

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

1. Ignition off
2. Reconnect the components, connectors etc.
3. Ignition on. Check the function of the electric engine block heater.

Does the system function?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «Information»(ref-406910-S21424009232011070100000)

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.

See Signal too low

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

1. Ignition off
2. Reconnect the components, connectors etc.
3. Ignition on. Check the function of the electric engine block heater.

Does the system function?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «Information»(ref-406910-S40684287832011070100000)

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.

Signal too high / Signal missing

See Signal too high / Signal missing

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

1. Ignition off
2. Reconnect the components, connectors etc.
3. Ignition on. Check the remote start function in the accessory electronic module by clicking on the VCT2000 symbol.

Does the system function?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «Information»(ref-406910-S00164712512011070100000)

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.

See Signal too low

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

1. Ignition off
2. Reconnect the components, connectors etc.
3. Ignition on. Check the remote start function in the accessory electronic module by clicking on the VCT2000 symbol.

Does the system function?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «Information»(ref-406910-S18259851802011070100000)

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.

See Signal too low

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

1. Ignition off
2. Reconnect the components, connectors etc.
3. Ignition on. Check the remote start function in the accessory electronic module by clicking on the VCT2000 symbol.

Does the system function?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «Information»(ref-406910-S12708080522011070100000)

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.

See Signal too high

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

1. Ignition off
2. Reconnect the components, connectors etc.
3. Ignition on. Check the function of the alarm by activating it appropriately.

Does the system function?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «Information»(ref-406910-S00174716672011070100000)

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.

Signal too low or signal missing

See Signal too low or signal missing

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

1. Ignition off
2. Reconnect the components, connectors etc.
3. Ignition on. Check the function of the alarm by activating it appropriately.

Does the system function?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «Information»(ref-406910-S23738824022011070100000)

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.

See Signal too high

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

1. Ignition off
2. Reconnect the components, connectors etc.
3. Ignition on. Check the function of the alarm by activating it appropriately.

Does the system function?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «Information»(ref-406910-S01266104172011070100000)

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.

See Signal too low or signal missing

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

1. Ignition off
2. Reconnect the components, connectors etc.
3. Ignition on. Check the function of the alarm by activating it appropriately.

Does the system function?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «Information»(ref-406910-S26875083532011070100000)

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.

See Signal too high

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

1. Ignition off
2. Reconnect the components, connectors etc.
3. Ignition on. Check the function of the alarm by activating it appropriately.

Does the system function?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «Information»(ref-406910-S34156378032011070100000)

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.

See Signal too low or signal missing

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

1. Ignition off
2. Reconnect the components, connectors etc.
3. Ignition on. Check the function of the alarm by activating it appropriately.

Does the system function?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «Information»(ref-406910-S06576185822011070100000)

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.

See Signal too high

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

1. Ignition off
2. Reconnect the components, connectors etc.
3. Ignition on. Check the function of the alarm by activating it appropriately.

Does the system function?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «Information»(ref-406910-S08401764772011070100000)

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.

See Signal too low

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

1. Ignition off
2. Reconnect the components, connectors etc.
3. Ignition on. Check the function of the alarm by activating it appropriately.

Does the system function?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «Information»(ref-406910-S28665080622011070100000)

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.

See Signal too high / Signal missing

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

1. Ignition off
2. Reconnect the components, connectors etc.
3. Ignition on. If the car is equipped with an original Volvo radio, check the carphone mute function in the accessory electronic module by clicking on the VCT2000 symbol while the radio is on. If the car is not equipped with an original Volvo radio, the carphone mute function is tested by making a call to the carphone while the radio is on.

Does the system function?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «Information»(ref-406910-S42900848132011070100000)

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.

See Signal too low

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

1. Ignition off
2. Reconnect the components, connectors etc.
3. Ignition on. If the car is equipped with an original Volvo radio, check the carphone mute function in the accessory electronic module by clicking on the VCT2000 symbol while the radio is on. If the car is not equipped with an original Volvo radio, the carphone mute function is tested by making a call to the carphone while the radio is on.

Does the system function?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «Information»(ref-406910-S24743174292011070100000)

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.

See Signal too high / Signal missing

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

1. Ignition off
2. Reconnect the components, connectors etc.
3. Ignition on. Check the rheostat function by clicking on the VCT2000 symbol while the radio is on.

Does the system function?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «Information»(ref-406910-S38404603302011070100000)

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.

Signal too low / high or signal missing

See Signal too low / high or signal missing

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

1. Ignition off
2. Reconnect the components, connectors etc.
3. Ignition on. Check the speed function by clicking on the VCT2000 symbol while the radio is on.

Does the system function?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «Information»(ref-406910-S02878294432011070100000)

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.

See Signal too low / high or signal missing

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

1. Ignition off
2. Reconnect the components, connectors etc.
3. Ignition on. Check the function of the antenna amplifier.

Does the system function?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «Information»(ref-406910-S34165906562011070100000)

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.

See Signal too low

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

1. Ignition off
2. Reconnect the components, connectors etc.
3. Ignition on. Check the function of the antenna amplifier.

Does the system function?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «Information»(ref-406910-S07172928482011070100000)

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.

See Signal too high / Signal missing

Faulty communication

See Faulty communication

Checking a short-circuit in CAN cables

Connect an ohmmeter between the relevant CAN cable (CAN-L and CAN-H) and the power supply, and between the CAN cable and ground. Twist the connectors and turn the cable harness to different positions at each reading to determine any intermittent short-circuits.

Take the following readings

1. The resistance between CAN-L and ground
2. The resistance between CAN-L and voltage
3. The resistance between CAN-H and ground
4. The resistance between CAN-H and voltage.

The resistance must be infinite or very high in all cases (greater than 1 Mohms).

HINT: The reading can be taken from the same connector if the CAN cables, power supply and ground are exposed. If possible, take readings on the rear of the connector to prevent damage to the terminals in the connector. If this is not possible, use the adapter wiring or loose terminal pins to obtain a good contact.

Was a fault detected?

1. YES Refer to «Identifying fault causes in the CAN network»(ref-406910-S27837671312011070100000)
2. NO Refer to «Checking the traffic load on the CAN cables»(ref-406910-S08332025832011070100000)

Checking the traffic load on the CAN cables

1. Connect the battery
2. Ignition on Also read: «Battery, disconnecting»(ref-406866-S10988298012011070100000) 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. Connect a voltmeter between CAN-L and ground. The voltage must be approximately 2. 3 V. Then connect a voltmeter between CAN-H and ground. The voltage must be approximately 2. 8 V. HINT: If possible measure from the rear of the affected connectors so that they are not damaged.

Is the value OK?

1. YES Refer to «Downloading new software»(ref-406910-S07470049682011070100000)
2. NO Refer to «Identifying a control module in the CAN network»(ref-406910-S19168679332011070100000)

Identifying fault causes in the CAN network

1. Disconnect a control module that disconnects the CAN network (a control module that has four terminals to the CAN network). HINT: For the low speed network, suitable places for disconnecting the network are at the steering wheel module (SWM), the driver information module (DIM) or the climate control module (CCM). In the event of a short-circuit between one of the CAN cables and voltage or ground, the fault can be located by disconnecting a control module that disconnects the CAN network. Readings can then be taken to determine on which side of the disconnected control module the fault is located. Connect an ohmmeter between the CAN cable and supply voltage or ground. Take readings at both ends of the CAN network where the network is disconnected. Twist and bend the cable harness to locate any intermittent short-circuits. The resistance must be infinite or very high (greater than 1Mohms). If a fault can be localized in one direction, disconnect the network at a point further down on the CAN network in the direction in which the fault was discovered and repeat the reading. In this way, try to identify where in the network the fault might be located. HINT: A short-circuit between the CAN cables and supply voltage or ground may be in either the wiring or in a control module. Rectify the wiring as necessary. Replace the control module if the fault has been localized to a control module.

1. Continue Refer to «Verification»(ref-406910-S31587565742011070100000)

Identifying a control module in the CAN network

1. Connect the battery Also read: «Battery, disconnecting»(ref-406866-S10988298012011070100000)
2. Ignition on 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. Connect a voltmeter between the CAN cables. If the communication on the network is correct, the average voltage value should be approximately 0. 5 V (0. 4 V to 0. 6 V). If there is a fault in the communication, the voltage reading will be approximately 0. 7 V or higher. In order to identify from which control module the faulty communication is being transmitted, cut the supply voltage to one control module at a time and check the voltage in the CAN cables again. The easiest way to cut the supply voltage is to remove a fuse. Repeat until the voltage between the CAN cables drops to approximately 0. 5 V. HINT: When the probable faulty control module has been identified, connect and disconnect the supply voltage to the control module a number of times to verify that the fault appears and disappears. NOTE: Do not cut the power to the central electronic module (CEM) unless it is the last control module left to check. The control module that is communicating incorrectly must be replaced. Remedy as necessary. NOTE: Following a fault involving "disruptive" control modules, other modules may remain in "Limp-Home mode" even after switching the ignition off and on a number of times. To remedy this, disconnect and reconnect the battery negative terminal to restore the control modules to normal function.

Was a fault detected?

1. YES Refer to «Verification»(ref-406910-S31587565742011070100000)
2. NO Refer to «Downloading new software»(ref-406910-S07470049682011070100000)

1. Disconnect a control module that disconnects the CAN network (a control module that has four terminals to the CAN network). HINT: For the low speed network, suitable places for disconnecting the network are at the steering wheel module (SWM), the driver information module (DIM) or the climate control module (CCM). In the event of an open-circuit or a short-circuit between the CAN cables, the fault can be localized by disconnecting a control module that disconnects the CAN network. Readings can then be taken to determine on which side of the disconnected control module the fault is located. Connect an ohmmeter between the CAN cables. Take readings at both ends of the CAN network where the network is disconnected. Twist and bend the cable harness to locate any intermittent short-circuits. The resistance must be 120 ohm. If a fault can be localized in one direction, disconnect the network at a point further down on the CAN network in the direction in which the fault was discovered and repeat the reading. In this way, try to identify where in the network the fault might be located. Remedy the cables as necessary.

Was a fault detected?

1. YES Refer to «Verification»(ref-406910-S31587565742011070100000)
2. NO Refer to «Downloading new software»(ref-406910-S07470049682011070100000)

Downloading new software

HINT: If no other faults are found, new software can be downloaded to remedy the fault in the control module which stored the diagnostic trouble code (DTC). Downloading of software must occur after agreement with the customer.

Downloading of software occurs according to the replacement parts catalogue/Index Software components.

HINT: Install a bookmark on this side to continue fault-tracing after downloading new software.

1. Continue Refer to «Verification»(ref-406910-S31587565742011070100000)

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

1. Reinstall the connectors, components, etc.
2. Ignition on
3. Erase diagnostic trouble codes by clicking the VCT2000 symbol
4. Start the car. Allow the car to run for 10 minutes.
5. Read off diagnostic trouble codes (DTCs). Does the diagnostic trouble code (DTC) for a communication fault recur (CEM-1A5X or CEM-1A6X)?

Does the diagnostic trouble code (DTC) recur?

1. YES Refer to «Information»(ref-406910-S25241408762011070100000)
2. NO OKAY: Troubleshooting has been completed.

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 resistance of the control area network (CAN) cables

1. Disconnect the battery negative lead. The power to the network must be cut when taking resistance readings. The reading may otherwise be incorrect. NOTE: Also read: Battery, disconnecting
2. Connect the adapter wiring to 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. When taking readings on the low speed network When taking readings on the low speed network, the adapter wiring should be connected to the central electronic module (CEM) and the readings taken from there. The readings can also be taken in the connector for the power seat module (PSM). The advantage of using the adapter wiring connected to the central electronic module (CEM) is that all control modules can be connected to the network when taking readings and there is access to both the high speed and the low speed networks. This resistance reading only measures main arteries in the low speed network, not the junctions for the road traffic information module (RTI), accessory electronic module (AEM), power seat module (PSM), phone module (PHM), audio module (AUM), driver's door module (DDM) and passenger door module (PDM). See the appropriate SYSTEM WIRING DIAGRAM article. When taking readings on the high speed network When taking readings on the high speed network, the readings should be taken at the engine control module (ECM) using adapter wiring. The engine control module (ECM) must be connected. This resistance reading only takes readings from the main arteries in the high speed network. See the appropriate SYSTEM WIRING DIAGRAM article. Connect the ohmmeter to the terminals for CAN-L and CAN-H on the relevant network. Work the connectors and twist the cable harness. The resistance must be approximately 60 ohms. Permitted values are 55-65 ohms. Other information See «Connecting the breakout box»(ref-406825-S28150951272011070100000) See «Checking wiring and terminals»(ref-406811-S00386154732011070100000)

Is the value OK?

1. YES Refer to «Checking a short-circuit in CAN cables»(ref-406910-S08224125902011070100000)
2. NO Refer to «Identifying fault causes in the CAN network»(ref-406910-S40523144502011070100000)

Connect an ohmmeter between the relevant CAN cable (CAN-L and CAN-H) and the power supply, and between the CAN cable and ground. Twist the connectors and turn the cable harness to different positions at each reading to determine any intermittent short-circuits.

Take the following readings

1. The resistance between CAN-L and ground
2. The resistance between CAN-L and voltage
3. The resistance between CAN-H and ground
4. The resistance between CAN-H and voltage.

The resistance must be infinite or very high in all cases (greater than 1 Mohms).

HINT: The reading can be taken from the same connector if the CAN cables, power supply and ground are exposed. If possible, take readings on the rear of the connector to prevent damage to the terminals in the connector. If this is not possible, use the adapter wiring or loose terminal pins to obtain a good contact.

Was a fault detected?

1. YES Refer to «Identifying fault causes in the CAN network»(ref-406910-S17405999302011070100000)
2. NO Refer to «Checking the traffic load on the CAN cables»(ref-406910-S16648514242011070100000)

1. Connect the battery
2. Ignition on Also read: «Battery, disconnecting»(ref-406866-S10988298012011070100000) 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. Connect a voltmeter between CAN-L and ground. The voltage must be approximately 2. 3 V. Then connect a voltmeter between CAN-H and ground. The voltage must be approximately 2. 8 V. HINT: If possible measure from the rear of the affected connectors so that they are not damaged.

Is the value OK?

1. YES Refer to «Downloading new software»(ref-406910-S31819562792011070100000)
2. NO Refer to «Identifying a control module in the CAN network»(ref-406910-S26600933922011070100000)

1. Disconnect a control module that disconnects the CAN network (a control module that has four terminals to the CAN network). HINT: For the low speed network, suitable places for disconnecting the network are at the steering wheel module (SWM), the driver information module (DIM) or the climate control module (CCM). In the event of a short-circuit between one of the CAN cables and voltage or ground, the fault can be located by disconnecting a control module that disconnects the CAN network. Readings can then be taken to determine on which side of the disconnected control module the fault is located. Connect an ohmmeter between the CAN cable and supply voltage or ground. Take readings at both ends of the CAN network where the network is disconnected. Twist and bend the cable harness to locate any intermittent short-circuits. The resistance must be infinite or very high (greater than 1Mohms). If a fault can be localized in one direction, disconnect the network at a point further down on the CAN network in the direction in which the fault was discovered and repeat the reading. In this way, try to identify where in the network the fault might be located. HINT: A short-circuit between the CAN cables and supply voltage or ground may be in either the wiring or in a control module. Rectify the wiring as necessary. Replace the control module if the fault has been localized to a control module.

1. Continue Refer to «Verification»(ref-406910-S09498513672011070100000)

1. Connect the battery Also read: «Battery, disconnecting»(ref-406866-S10988298012011070100000)
2. Ignition on 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. Connect a voltmeter between the CAN cables. If the communication on the network is correct, the average voltage value should be approximately 0. 5 V (0. 4 V to 0. 6 V). If there is a fault in the communication, the voltage reading will be approximately 0. 7 V or higher. In order to identify from which control module the faulty communication is being transmitted, cut the supply voltage to one control module at a time and check the voltage in the CAN cables again. The easiest way to cut the supply voltage is to remove a fuse. Repeat until the voltage between the CAN cables drops to approximately 0. 5 V. HINT: When the probable faulty control module has been identified, connect and disconnect the supply voltage to the control module a number of times to verify that the fault appears and disappears. NOTE: Do not cut the power to the central electronic module (CEM) unless it is the last control module left to check. The control module that is communicating incorrectly must be replaced. Remedy as necessary. NOTE: Following a fault involving "disruptive" control modules, other modules may remain in "Limp-Home mode" even after switching the ignition off and on a number of times. To remedy this, disconnect and reconnect the battery negative terminal to restore the control modules to normal function.

Was a fault detected?

1. YES Refer to «Verification»(ref-406910-S09498513672011070100000)
2. NO Refer to «Downloading new software»(ref-406910-S31819562792011070100000)

1. Disconnect a control module that disconnects the CAN network (a control module that has four terminals to the CAN network). HINT: For the low speed network, suitable places for disconnecting the network are at the steering wheel module (SWM), the driver information module (DIM) or the climate control module (CCM). In the event of an open-circuit or a short-circuit between the CAN cables, the fault can be localized by disconnecting a control module that disconnects the CAN network. Readings can then be taken to determine on which side of the disconnected control module the fault is located. Connect an ohmmeter between the CAN cables. Take readings at both ends of the CAN network where the network is disconnected. Twist and bend the cable harness to locate any intermittent short-circuits. The resistance must be 120 ohm. If a fault can be localized in one direction, disconnect the network at a point further down on the CAN network in the direction in which the fault was discovered and repeat the reading. In this way, try to identify where in the network the fault might be located. Remedy the cables as necessary.

Was a fault detected?

1. YES Refer to «Verification»(ref-406910-S09498513672011070100000)
2. NO Refer to «Downloading new software»(ref-406910-S31819562792011070100000)

HINT: If no other faults are found, new software can be downloaded to remedy the fault in the control module which stored the diagnostic trouble code (DTC). Downloading of software must occur after agreement with the customer.

Downloading of software occurs according to the replacement parts catalogue/Index Software components.

HINT: Install a bookmark on this side to continue fault-tracing after downloading new software.

1. Continue Refer to «Verification»(ref-406910-S09498513672011070100000)

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

1. Reinstall the connectors, components, etc.
2. Ignition on
3. Erase diagnostic trouble codes by clicking the VCT2000 symbol
4. Start the car. Allow the car to run for 10 minutes.
5. Read off diagnostic trouble codes (DTCs). Does the diagnostic trouble code (DTC) for a communication fault recur (CEM-1A5X or CEM-1A6X)?

Does the diagnostic trouble code (DTC) recur?

1. YES Refer to «Information»(ref-406910-S31282029772011070100000)
2. NO OKAY: Troubleshooting has been completed.

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 function

1. Ignition off. Check whether the fault is due to the ignition switch lighting or the high level stop lamp. NOTE: High level stop lamp applies only to S60/S80. For other models this is powered by the rear electronic module (REM). The ignition switch lighting comes on when the car is unlocked and goes out when the car is locked or the engine is running. The high level stop lamp must light when the brake pedal is depressed and go out when the pedal is released. Select the function to be fault-traced. 1. Ignition switch lighting 2. High level stop lamp.

Select an alternative.

1. 1 Refer to «Checking the ignition switch lighting»(ref-406910-S09326622182011070100000)
2. 2 Refer to «Checking the high level stop lamps»(ref-406910-S08309523222011070100000)

Scheme 301

Scheme 302

1. Ignition off. Check that the bulb is intact. Check the connectors for the central electronic module (CEM) and ignition switch lighting. Check for contact resistance and oxidation. Check for loose connections. Check for damage carefully. Check the power supply cable between central electronic module (CEM) terminal #19D (#B19) and ignition switch lighting terminal #5. Check for an open-circuit. Check for a short-circuit to supply voltage. Check the ground lead between ignition switch terminal #6 and the ground terminal. Check for an open-circuit. Check for a short-circuit to supply voltage. Remedy as necessary. Other information To access the bulb and connector for the ignition switch, see «Bulb, ignition switch, replacing»(ref-406830-S08126403882011070100000) To access the central electronic module (CEM), see «Central electronic module (CEM), replacing»(ref-441112-S09232038292011121500000) To connect the breakout box, see «Connecting the breakout box»(ref-406825-S28150951272011070100000) For information about signals, see «Signal specification»(ref-406816-S38647568162011070100000) See «Checking wiring and terminals»(ref-406811-S00386154732011070100000) For further information about the cables and ground terminals, see the appropriate SYSTEM WIRING DIAGRAM article.

1. Continue Refer to «Verification»(ref-406910-S25158452522011070100000)

Scheme 303

1. Ignition off. Check the central electronic module (CEM) and the high-mounted stop lamp connectors. Check for contact resistance and oxidation. Check for loose connections. Check for damage carefully. Check the power supply cable between central electronic module (CEM) terminal #5B (#A25) and brake light connector terminal #1. Check for an open-circuit. Check for a short-circuit to supply voltage. Check the ground lead between brake light connector terminal #5 and the ground terminal. Check for an open-circuit. Check for a short-circuit to supply voltage. Try a new brake light if no faults were found. Remedy as necessary. Other information: To access / replace the high mounted stop lamp, see «Stop lamp, rear windshield, replacing»(ref-406883-S22212888812011070100000) To access the central electronic module (CEM), see «Central electronic module (CEM), replacing»(ref-441112-S09232038292011121500000) To connect the breakout box, see «Connecting the breakout box»(ref-406825-S28150951272011070100000) For information about signals, see «Signal specification»(ref-406816-S38647568162011070100000) See «Checking wiring and terminals»(ref-406811-S00386154732011070100000) For further information about the cables and ground terminals, see the appropriate SYSTEM WIRING DIAGRAM article.

1. Continue Refer to «Verification»(ref-406910-S25158452522011070100000)

HINT: After the repair it is necessary to check that the fault has been rectified.

1. Ignition off.
2. Connect the connectors, install the components, etc.
3. Ignition on. Read the diagnostic trouble codes. If diagnostic trouble code has changed to intermittent status this indicates that the fault is no longer activated.

Is the diagnostic trouble code intermittent?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «Information»(ref-406910-S07896645502011070100000)

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.

Stop lamp, rear windshield, replacing

Special tools

9512636

Removing the stop lamp

Use clean gloves

To avoid customer complaints

1. gloves which leave no prints must be used
2. visible surfaces, where the stop lamp can cover the rear windshield, must be kept unmarked and fault-free
3. visible surfaces on the stop lamp must be kept unmarked and fault-free.

Preparatory work

Scheme 304

Remove

1. three rear clips (1) in the headlining by twisting a quarter of a turn and pulling it out
2. the rear interior lighting (2). The mounting mechanism consists of metal springs
3. foam rubber (3) from the top of the headlining. Be careful. It must be reused. NOTE: Note the position of the foam rubber.
4. connector (4) from the stop lamp
5. stop lamp wiring. Pull it out through the hole for the rear interior lighting.

Removing the stop lamp

Scheme 305

Use a weatherstrip tool to cut as close to the stop lamp tape as possible. This is to avoid damaging the headlining.

Start with the two pieces of tape on the section that points forwards. Then cut the two pieces of tape closest to the rear windshield.

Do one corner at a time.

Reversing polarity of cables

Opening the secondary catch

Scheme 306

Use a thin screwdriver with a 3-4mm wide blade.

Carefully undo the hooks on the secondary catch.

Removing cable

Scheme 307

Note. Transfer one cable at a time.

Press the cable terminal through the cavity.

Insert the terminal removal tool 9512636 from the contact side into the upper cavity bank, by the cable terminal. The beveled side of the tool should face sideways.

Extract the cable terminal.

Repeat for each cable.

Checking the cable terminal

Scheme 308

Inspect the locking tabs on the terminal for damage. Check that the tabs are not pressed inward.

Installing the cable

Scheme 309

Use a new connector, P/N 978305.

Install the yellow-red cable in terminal 1.

Install the brown cable in terminal 5.

When the cable terminal is inserted in the cavity a click is often heard when the primary catch engages.

Pull the cable gently to check that the cable terminal is properly seated in the cavity.

Closing the secondary catch

Scheme 310

When the secondary catch is closed a click is often heard.

If it cannot be closed this might be because the cable terminal is not completely inserted in the cavity.

Installing components

Testing the stop lamp

Scheme 311

Connect a new stop lamp.

Check its function.

Disconnect it.

Removing the backing

Scheme 312

Remove the backing (1) from the double-sided adhesive tape on the stop lamp.

Installing the stop lamp

Scheme 313

Position the stop lamp on the headlining with the bevel (1) against the headlining. Do not allow the double-sided adhesive tape touch the headlining.

Note. To avoid squeaking it is important that the stop lamp is correctly positioned on the headlining.

Press the stop lamp into place on the headlining.

Finishing work

Scheme 314

Connect the connector (1) to the stop lamp.

Tape (2) stop lamp wiring to the headlining so that they cannot make a noise.

Install foam rubber (3), just behind the hole for the rear interior lighting. Use contact adhesive, P/N 1161434, if there is too little adhesive left on the foam rubber for it to stick to the headlining.

Install clip (4) in the headlining by pressing straight up and twisting a quarter turn.

Install the interior lighting (5) by pressing straight up.

Checking the connectors

1. Ignition off. Check central electronic module (CEM) connector D. Check for contact resistance and oxidation. Check for loose connections. Remedy as necessary. Check for any damage. HINT: If the fault cause is found, reinstall the components, connectors etc. HINT: If the fault cause was not found, do not reconnect the connector before carrying out further fault-tracing. Other information: To replace the connectors for the central electronic module (CEM), see: «Central electronic module (CEM), replacing»(ref-441112-S09232038292011121500000) See «Contents»(ref-406811-S37635188302011070100000)

Was a fault detected?

1. YES Refer to «Verification»(ref-406910-S05063812512011070100000)
2. NO Refer to «Checking the component and cable»(ref-406910-S01607385222011070100000)

Scheme 315

1. Ignition off
2. Remove the ignition key. Check the cable between central electronic module (CEM) terminal #D15 and ignition switch terminal #S (#3). Check for an open-circuit. Check for a short-circuit to ground. The voltage must be battery voltage when the key is in the ignition switch. Remedy as necessary. Other information: See «Connecting the breakout box»(ref-406825-S11308929022011070100000) See «Signal specification»(ref-406816-S38647568162011070100000) See «Central electronic module (CEM), replacing»(ref-441112-S09232038292011121500000) See «Contents»(ref-406811-S37635188302011070100000)

Was a fault detected?

1. YES Refer to «Verification»(ref-406910-S05063812512011070100000)
2. NO Refer to «Replacing the ignition switch»(ref-406910-S12356125312011070100000)

Replacing the ignition switch

To replace the connector for the ignition switch, see: Steering wheel lock, replacing

1. Continue Refer to «Verification»(ref-406910-S05063812512011070100000)

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. Check whether the S-supply is activated.

Is the S-supply activated?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «Information»(ref-406910-S02146866742011070100000)

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.

Check the central electronic module (CEM) connector for contact resistance and oxidation and remedy according to Contact resistance and oxidation and loose connections according to Loose connections (terminals) .

Check for damage carefully.

HINT: If the fault cause is found, reinstall the components, connectors etc.

HINT: If the fault cause is not found, do not reinstall the control module before continuing with fault-tracing.

Other information

1. To access / replace the central electronic module (CEM) connector, see «Central electronic module (CEM), replacing»(ref-441112-S09232038292011121500000) .

Was a fault detected?

1. YES OKAY: Troubleshooting has been completed.
2. NO Refer to «Checking wiring»(ref-406910-S38447823132011070100000)

1. Ignition off. Check the central electronic module (CEM) connector for contact resistance and oxidation. Remedy if necessary. Check for any damage. HINT: If the fault cause is found, reinstall the components, connectors etc. If the fault cause is not found, do not reinstall the control module before continuing with fault-tracing. Other information: To access or replace the central electronic module (CEM) connector, see «Central electronic module (CEM), replacing»(ref-441112-S09232038292011121500000) See «Checking wiring and terminals. Permanent fault»(ref-441113-S28151161662011121500000) .

Was a fault detected?

1. YES Refer to «Verification»(ref-406910-S26998273502011070100000)
2. NO Refer to «Checking the component and cable»(ref-406910-S11148671512011070100000)

Checking the component and cable

1. Ignition off. Check the cable between control module terminal #1B and ignition switch terminal #S (#3). Check for an open-circuit. Check for a short-circuit to ground. Remedy as necessary. Other information: The voltage must be the same as battery voltage if the key is in position 0, I, II or III To access or replace the central electronic module (CEM) connector, see «Central electronic module (CEM), replacing»(ref-441112-S09232038292011121500000) To connect the breakout box to the control module, see «Connecting the breakout box»(ref-406825-S28150951272011070100000) For further information about signals and other values, see «Signal specification»(ref-406816-S38647568162011070100000) See «Checking wiring and terminals. Permanent fault»(ref-441113-S28151161662011121500000) .

Was a fault detected?

1. YES Refer to «Verification»(ref-406910-S26998273502011070100000)
2. NO Refer to «Replacing the ignition switch connector»(ref-406910-S42868975782011070100000)

Replacing the ignition switch connector

Try replacing the ignition switch connector according to Steering wheel lock, replacing .

1. Continue Refer to «Verification»(ref-406910-S26998273502011070100000)

HINT: After the repair it is necessary to check that the fault has been rectified.

1. Ignition off.
2. Connect connectors, install components, etc.
3. Ignition on. Check that S voltage is OK.

Is voltage on the wire high?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «Information»(ref-406910-S40505569062011070100000)

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.

1. Ignition off. Check central electronic module (CEM) connector D. Check for contact resistance and oxidation. Remedy as necessary. Check for any damage. HINT: If the fault cause is found, reinstall the components, connectors etc. HINT: If the fault cause was not found, do not reconnect the connector before carrying out further fault-tracing. Other information: To replace the connectors for the central electronic module (CEM), see: «Central electronic module (CEM), replacing»(ref-441112-S09232038292011121500000)

Was a fault detected?

1. YES Refer to «Verification»(ref-406910-S33046739092011070100000)
2. NO Refer to «Checking the component and cable»(ref-406910-S00345861932011070100000)

1. Ignition off. Check the cable between central electronic module (CEM) connector terminal #D8 and the ignition switch X-supply (terminal #6). Check for an open-circuit. Check for a short-circuit to ground. Switch on the ignition. The voltage must be the same as battery voltage if the key is in position I or II. HINT: For the intermediate junction point and fuse, see the appropriate SYSTEM WIRING DIAGRAM article. Other information: See «Connecting the breakout box»(ref-406825-S11308929022011070100000) See «Signal specification»(ref-406816-S38647568162011070100000) See «Central electronic module (CEM), replacing»(ref-441112-S09232038292011121500000) See «Contents»(ref-406811-S37635188302011070100000)

Is the voltage OK?

1. YES Refer to «Verification»(ref-406910-S33046739092011070100000)
2. NO Refer to «Replacing the ignition switch»(ref-406910-S19511017692011070100000)

To replace the connector for the ignition switch, see: Steering wheel lock, replacing

1. Continue Refer to «Verification»(ref-406910-S33046739092011070100000)

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. Check that the X-supply is OK.

Is the voltage high on the cable?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «Information»(ref-406910-S06607507812011070100000)

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.

Check the central electronic module (CEM) connector. Check for contact resistance and oxidation according to Contact resistance and oxidation . Check for loose connections according to Loose connections (terminals) .

Check for any damage.

HINT: If the fault cause is found, reinstall the components, connectors etc.

HINT: If the fault cause is not found, do not reinstall the central electronic module (CEM) before continuing with fault-tracing.

Other information

1. To access or replace the central electronic module (CEM) connector, see «Central electronic module (CEM), replacing»(ref-441112-S09232038292011121500000)

Was a fault detected?

1. YES OKAY: Troubleshooting has been completed.
2. NO Refer to «Checking the cable»(ref-406910-S32476349822011070100000)

Checking the cable

Check the cable between central electronic module connector terminal #2B and the ignition switch connector terminal #x. Check for an open-circuit according to Open-circuit, intermittent faults . Check for a short-circuit to ground according to Short-circuit to ground, intermittent faults .

Other information

1. The voltage must be the same as battery voltage if the key is in positions I or II
2. To access or replace the central electronic module (CEM) connector, see «Central electronic module (CEM), replacing»(ref-441112-S09232038292011121500000)
3. To connect the breakout box to the control module, see «Connecting the breakout box»(ref-406825-S28150951272011070100000)
4. For further information about signals and other values, see «Signal specification»(ref-406816-S38647568162011070100000)
5. For the intermediate junction point and fuse, see appropriate SYSTEM WIRING DIAGRAM article.

1. Continue OKAY: Troubleshooting has been completed.

1. Ignition off. Check the central electronic module (CEM) connector for contact resistance and oxidation. Remedy if necessary. Check for any damage. HINT: If the fault cause is found, reinstall the components, connectors etc. If the fault cause is not found, do not reinstall the control module before continuing with fault-tracing. Other information: To access or replace the central electronic module (CEM) connector, see «Central electronic module (CEM), replacing»(ref-441112-S09232038292011121500000) .

Was a fault detected?

1. YES Refer to «Verification»(ref-406910-S30456458702011070100000)
2. NO Refer to «Checking the component and cable»(ref-406910-S35810327632011070100000)

1. Ignition off. Check the cable between central electronic module (CEM) connector terminal #2B and the ignition switch X-supply (terminal #6). Check for an open-circuit. Check for a short-circuit to ground. Other information: The voltage must be the same as battery voltage if the key is in position I or II For the intermediate junction point and fuse, see appropriate SYSTEM WIRING DIAGRAM article To access or replace the central electronic module (CEM) connector, see «Central electronic module (CEM), replacing»(ref-441112-S09232038292011121500000) To connect the breakout box to the control module, see «Connecting the breakout box»(ref-406825-S28150951272011070100000) For further information about signals and other values, see «Signal specification»(ref-406816-S38647568162011070100000) See «Checking wiring and terminals»(ref-406811-S00386154732011070100000) .

Is the voltage the same as battery voltage?

1. YES Refer to «Verification»(ref-406910-S30456458702011070100000)
2. NO Refer to «Replacing the ignition switch connector»(ref-406910-S31003252502011070100000)

Try replacing the ignition switch connector according to Steering wheel lock, replacing .

1. Continue Refer to «Verification»(ref-406910-S30456458702011070100000)

HINT: After the repair it is necessary to check that the fault has been rectified.

1. Ignition off.
2. Connect connectors, install components, etc.
3. Ignition on. Check that X-voltage is OK.

Is voltage on the wire high?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «Information»(ref-406910-S24428852632011070100000)

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.

1. Ignition off. Check central electronic module (CEM) connector D. Check for damage. Remedy as necessary. HINT: If the fault cause is found, reinstall the components, connectors etc. HINT: If the fault cause was not found, do not reconnect the connector before carrying out further fault-tracing. Other information: To replace the connectors for the central electronic module (CEM), see: «Central electronic module (CEM), replacing»(ref-441112-S09232038292011121500000) See «Contents»(ref-406811-S37635188302011070100000)

Was a fault detected?

1. YES Refer to «Verification»(ref-406910-S06394097212011070100000)
2. NO Refer to «Checking the component and cable»(ref-406910-S16896816402011070100000)

1. Ignition off. Check the cable between central electronic module (CEM) connector terminal #D8 and the ignition switch X-supply (terminal #6). Check for a short-circuit to supply voltage. The voltage must be 0 V if the key is in position 0 or III. HINT: For the intermediate junction point and fuses, see the appropriate SYSTEM WIRING DIAGRAM article. Other information: See «Connecting the breakout box»(ref-406825-S11308929022011070100000) See «Signal specification»(ref-406816-S38647568162011070100000) See «Central electronic module (CEM), replacing»(ref-441112-S09232038292011121500000) See «Contents»(ref-406811-S37635188302011070100000)

Were any faults found in the cable?

1. YES Refer to «Verification»(ref-406910-S06394097212011070100000)
2. NO Refer to «Replacing the ignition switch»(ref-406910-S36837377432011070100000)

To replace the connector for the ignition switch, see: Steering wheel lock, replacing

1. Continue Refer to «Verification»(ref-406910-S06394097212011070100000)

HINT: After the repair it is necessary to check that the fault has been rectified.

Scheme 316

1. Ignition off.
2. Connect connectors, install components, etc.
3. Key in position III. Check that X-voltage is OK.

Is voltage on the wire low?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «Information»(ref-406910-S27073536452011070100000)

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 wire between battery and alternator.

Check the wire between alternator 1A and starter motor 1 (red/green wire and flat pin) for an open circuit as described in Open-circuit, intermittent faults , and for a short circuit to ground as described in Short-circuit to ground, intermittent faults .

Also check the wire between starter motor 1 and battery positive terminal in the same way.

Is there a fault?

1. YES Refer to «Information»(ref-406910-S05260333172011070100000)
2. NO Refer to «Checking the wires and connectors»(ref-406910-S04964664432011070100000)

Checking the wires and connectors

Check wires and connectors between central electronic module (CEM) 6E and battery for an intermittent open circuit as described in Open-circuit, intermittent faults and for a loose contact as described in Loose connections (terminals) . Check especially for any damage.

Check wires between central electronic module (CEM) 1E and ground point/ground on left A-pillar (right A-pillar, RHD) for an open circuit as described in Open-circuit, intermittent faults . Check especially for any damage.

Do the necessary corrective action.

Additional information

1. To access connector 54/3R, see appropriate SYSTEM WIRING DIAGRAM article.
2. To access control unit connector, see «Central electronic module (CEM), replacing»(ref-441112-S09232038292011121500000)
3. To connect a test box, see «Connecting the breakout box»(ref-406825-S28150951272011070100000)

1. Continue Refer to «Information»(ref-406910-S05260333172011070100000)

If the fault is intermittent, do not verify fault-tracing if the fault does not recur.

It is possible to view the information again, or leave fault-tracing for this diagnostic trouble code (DTC).

Checking the cable between the battery and the generator (GEN)

Check that the battery is charged.

Charge the battery if necessary.

Check the cable between generator (GEN) terminal #1A and starter motor terminal #1 (the red / green flat pin cable). Check for an open-circuit. Check for a short-circuit to ground. Also check the cable between starter motor terminal #1 and the battery positive terminal in the same way.

Other information

1. See «Checking wiring and terminals»(ref-406811-S00386154732011070100000) .

Was a fault detected?

1. YES Refer to «Verification»(ref-406910-S29249022402011070100000)
2. NO Refer to «Checking the power supply»(ref-406910-S25207456052011070100000)

Checking the power supply

Check the voltage to ground at the following points

1. main fuse 11A/2
2. fuse 11C/32.

The voltage must be at least battery voltage minus three volts.

Check for contact resistance and oxidation at the fuses.

Remedy as necessary.

Other information

1. For further information about the fuses and relays, see the appropriate SYSTEM WIRING DIAGRAM article.

Scheme 317

Was a fault detected?

1. YES Refer to «Verification»(ref-406910-S29249022402011070100000)
2. NO Refer to «Checking the power supply and ground terminals»(ref-406910-S24138383372011070100000)

Checking the power supply and ground terminals

Check connector 54/3. Check for contact resistance and oxidation. Check for damage carefully.

Check the voltage to ground at control module connector terminal #6E. The voltage must be at least battery voltage minus three volts.

Check the central electronic module (CEM) connector. Check for contact resistance and oxidation. Check for damage carefully.

Check the wiring between control module terminal #1E and ground: left A-post (right A-post for right-hand drive cars) for loose connections.

Other information

1. To access connector 54/3, see appropriate SYSTEM WIRING DIAGRAM article. (Also (Scheme 318))
2. To access the central electronic module (CEM) connector, see «Central electronic module (CEM), replacing»(ref-441112-S09232038292011121500000)
3. To connect the breakout box, see «Connecting the breakout box»(ref-406825-S28150951272011070100000)
4. See «Checking wiring and terminals»(ref-406811-S00386154732011070100000).

Scheme 318

Was a fault detected?

1. YES Refer to «Verification»(ref-406910-S29249022402011070100000)
2. NO Refer to «Checking the battery»(ref-406910-S08594385132011070100000)

Checking the battery

Check the condition of the battery.

Is the battery OK?

1. YES Refer to «Checking the generator (GEN)»(ref-406910-S33378984542011070100000)
2. NO Refer to «Battery»(ref-406910-S41930647902011070100000)

Battery

Replace the battery.

Other information

1. When replacing the battery, see «Battery, disconnecting»(ref-406866-S10988298012011070100000) .

1. Continue Refer to «Verification»(ref-406910-S29249022402011070100000)

Checking the generator (GEN)

Check that the generator (GEN) is working correctly.

Try a new generator (GEN).

Replace the generator (GEN) for gasoline engines. See GENERATOR (GEN), REPLACING .

Replace the generator (GEN) for diesel engines. See Generator (GEN), replacing .

1. Continue Refer to «Verification»(ref-406910-S29249022402011070100000)

HINT: After the repair it is necessary to check that the fault has been rectified.

1. Ignition off.
2. Connect connectors, install components, etc.
3. Charge the battery.
4. Start the vehicle and let it remain idle for at least 5 minutes. Read the power supply to the central electronic module (CEM). Voltage should be at least battery voltage minus three volts.

Is voltage OK?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «Information»(ref-406910-S34462352512011070100000)

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.

Check the central electronic module (CEM) connector for contact resistance and oxidation and remedy according to Contact resistance and oxidation and loose connections according to Loose connections (terminals) .

Check for damage carefully.

HINT: If the fault cause is found, reinstall the components, connectors etc.

HINT: If the fault cause is not found, do not reinstall the central electronic module (CEM) before continuing with fault-tracing.

Other information

1. To access the central electronic module (CEM) connector, see «Central electronic module (CEM), replacing»(ref-441112-S09232038292011121500000) .

Was a fault detected?

1. YES OKAY: Troubleshooting has been completed.
2. NO Refer to «Checking wiring»(ref-406910-S29405953932011070100000)

1. Ignition off. Check the central electronic module (CEM) connector for contact resistance and oxidation. Remedy if necessary. Check for any damage. HINT: If the fault cause is found, reinstall the components, connectors etc. If the fault cause is not found, do not reinstall the control module before continuing with fault-tracing. Other information: To access the central electronic module (CEM) connector, see «Central electronic module (CEM), replacing»(ref-441112-S09232038292011121500000) See «Checking wiring and terminals»(ref-406811-S00386154732011070100000) .

Was a fault detected?

1. YES Refer to «Verification»(ref-406910-S17941973132011070100000)
2. NO Refer to «Checking the component and cable»(ref-406910-S35906766672011070100000)

1. Ignition off. Check the cable between central electronic module (CEM) connector terminal #2B and ignition switch connector X-supply (terminal #6). Check for a short-circuit to supply voltage. Check for an open-circuit. Other information: The voltage must be 0 V if the key is in position 0 or III To access or replace the central electronic module (CEM) connector, see «Central electronic module (CEM), replacing»(ref-441112-S09232038292011121500000) For the intermediate junction point, see appropriate SYSTEM WIRING DIAGRAM article To connect the breakout box to the control module, see «Connecting the breakout box»(ref-406825-S28150951272011070100000) For further information about signals and other values, see «Signal specification»(ref-406816-S38647568162011070100000) See «Checking wiring and terminals»(ref-406811-S00386154732011070100000) .

Were any faults found in the cable?

1. YES Refer to «Verification»(ref-406910-S17941973132011070100000)
2. NO Refer to «Replacing the ignition switch connector»(ref-406910-S25660567082011070100000)

Try replacing the ignition switch connector according to Steering wheel lock, replacing .

1. Continue Refer to «Verification»(ref-406910-S17941973132011070100000)

HINT: After the repair it is necessary to check that the fault has been rectified.

1. Ignition off.
2. Connect connectors, install components, etc.
3. Key in position III. Check that X-voltage is OK.

Is voltage on the wire low?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «Information»(ref-406910-S36343553022011070100000)

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.

1. Ignition off. Check central electronic module (CEM) connector D. Check for contact resistance and oxidation. Remedy as necessary. Check for any damage. HINT: If the fault cause is found, reinstall the components, connectors etc. HINT: If the fault cause was not found, do not reconnect the connector before carrying out further fault-tracing. Other information: To replace the connectors for the central electronic module (CEM), see: «Central electronic module (CEM), replacing»(ref-441112-S09232038292011121500000) See «Contents»(ref-406811-S37635188302011070100000)

Was a fault detected?

1. YES Refer to «Verification»(ref-406910-S26521995262011070100000)
2. NO Refer to «Checking the component and cable»(ref-406910-S35591404612011070100000)

1. Ignition off. Check the cable between central electronic module (CEM) connector terminal #D16 and ignition switch connector terminal #15A (#1). Check for an open-circuit. Check for a short-circuit to ground. The voltage must be the same as battery voltage if the key is in position I or III. Remedy as necessary. HINT: For intermediate junction points, see the appropriate SYSTEM WIRING DIAGRAM article. Other information: See «Connecting the breakout box»(ref-406825-S11308929022011070100000) See «Signal specification»(ref-406816-S38647568162011070100000) See «Central electronic module (CEM), replacing»(ref-441112-S09232038292011121500000) See «Contents»(ref-406811-S37635188302011070100000)

Is the voltage the same as battery voltage?

1. YES Refer to «Verification»(ref-406910-S26521995262011070100000)
2. NO Refer to «Replacing the ignition switch»(ref-406910-S04526745742011070100000)

To replace the connector for the ignition switch, see: Steering wheel lock, replacing

1. Continue Refer to «Verification»(ref-406910-S26521995262011070100000)

HINT: After the repair it is necessary to check that the fault has been rectified.

1. Ignition off.
2. Connect connectors, install components, etc.
3. Key in position III. Check that 15 voltage is OK.

Is voltage on the wire high?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «Information»(ref-406910-S07297001652011070100000)

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.

Check the central electronic module (CEM) connector for contact resistance and oxidation and remedy according to Contact resistance and oxidation and loose connections according to Loose connections (terminals) .

Check for damage carefully.

HINT: If the fault cause is found, reinstall the components, connectors etc.

HINT: If the fault cause is not found, do not reinstall the central electronic module (CEM) before continuing with fault-tracing.

Other information

1. To access the central electronic module (CEM) connector, see «Central electronic module (CEM), replacing»(ref-441112-S09232038292011121500000) .

Was a fault detected?

1. YES OKAY: Troubleshooting has been completed.
2. NO Refer to «Checking wiring»(ref-406910-S29104048892011070100000)

1. Ignition off. Check the central electronic module (CEM) connector for contact resistance and oxidation. Remedy if necessary. Check for any damage. HINT: If the fault cause is found, reinstall the components, connectors etc. If the fault cause is not found, do not reinstall the control module before continuing with fault-tracing. Other information: To access the central electronic module (CEM) connector, see «Central electronic module (CEM), replacing»(ref-441112-S09232038292011121500000) See «Checking wiring and terminals»(ref-406811-S00386154732011070100000) .

Was a fault detected?

1. YES Refer to «Verification»(ref-406910-S09104310132011070100000)
2. NO Refer to «Checking the component and cable»(ref-406910-S13697962322011070100000)

1. Ignition off. Check the cable between central electronic module (CEM) connector terminal #3B and ignition switch connector 15A terminal #1. Check for an open-circuit. Check for a short-circuit to ground. Other information: The voltage must be the same as battery voltage if the key is in position II or III To access or replace the central electronic module (CEM) connector, see «Central electronic module (CEM), replacing»(ref-441112-S09232038292011121500000) For the intermediate junction point, see appropriate SYSTEM WIRING DIAGRAM article To connect the breakout box to the control module, see «Connecting the breakout box»(ref-406825-S28150951272011070100000) For further information about signals and other values, see «Signal specification»(ref-406816-S38647568162011070100000) See «Checking wiring and terminals»(ref-406811-S00386154732011070100000) .

Is the voltage the same as battery voltage?

1. YES Refer to «Verification»(ref-406910-S09104310132011070100000)
2. NO Refer to «Replacing the ignition switch connector»(ref-406910-S29112592602011070100000)

Try replacing the ignition switch connector according to Steering wheel lock, replacing .

1. Continue Refer to «Verification»(ref-406910-S09104310132011070100000)

HINT: After the repair it is necessary to check that the fault has been rectified.

1. Ignition off.
2. Connect connectors, install components, etc.
3. Key in position III. Check that 15 voltage is OK.

Is voltage on the wire high?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «Information»(ref-406910-S11720744682011070100000)

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.

1. Ignition off. Check central electronic module (CEM) connector D. Check for contact resistance and oxidation. Remedy as necessary. Check for any damage. HINT: If the fault cause is found, reinstall the components, connectors etc. HINT: If the fault cause was not found, do not reconnect the connector before carrying out further fault-tracing. Other information: To replace the connectors for the central electronic module (CEM), see: «Central electronic module (CEM), replacing»(ref-441112-S09232038292011121500000) See «Contents»(ref-406811-S37635188302011070100000)

Was a fault detected?

1. YES Refer to «Verification»(ref-406910-S20014613282011070100000)
2. NO Refer to «Checking the component and cable»(ref-406910-S07597265452011070100000)

1. Ignition off. Check the cable between central electronic module (CEM) connector terminal #D16 and ignition switch connector terminal #1. Check for a short-circuit to supply voltage. The voltage must be 0 V if the key is in position 0 or I. HINT: For intermediate junction points, see the appropriate SYSTEM WIRING DIAGRAM article. Other information: See «Connecting the breakout box»(ref-406825-S11308929022011070100000) See «Signal specification»(ref-406816-S38647568162011070100000) See «Central electronic module (CEM), replacing»(ref-441112-S09232038292011121500000) See «Contents»(ref-406811-S37635188302011070100000)

Were any faults found in the cable?

1. YES Refer to «Verification»(ref-406910-S20014613282011070100000)
2. NO Refer to «Replacing the ignition switch»(ref-406910-S04478347522011070100000)

To replace the connector for the ignition switch, see: Steering wheel lock, replacing

1. Continue Refer to «Verification»(ref-406910-S20014613282011070100000)

HINT: After the repair it is necessary to check that the fault has been rectified.

1. Ignition off.
2. Connect connectors, install components, etc.
3. Ignition off. Check that 15 voltage is OK.

Is voltage on the wire low?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «Information»(ref-406910-S00357332702011070100000)

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.

Check the central electronic module (CEM) connector for contact resistance and oxidation and remedy according to Contact resistance and oxidation and loose connections according to Loose connections (terminals) .

Check for damage carefully.

HINT: If the fault cause is found, reinstall the components, connectors etc.

HINT: If the fault cause is not found, do not reinstall the central electronic module (CEM) before continuing with fault-tracing.

Other information

1. To access the central electronic module (CEM) connector, see «Central electronic module (CEM), replacing»(ref-441112-S09232038292011121500000)

Was a fault detected?

1. YES OKAY: Troubleshooting has been completed.
2. NO Refer to «Checking wiring»(ref-406910-S40346345822011070100000)

1. Ignition off. Check the central electronic module (CEM) connector for contact resistance and oxidation. Remedy if necessary. Check for any damage. HINT: If the fault cause is found, reinstall the components, connectors etc. If the fault cause is not found, do not reinstall the control module before continuing with fault-tracing. Other information: To access the central electronic module (CEM) connector, see «Central electronic module (CEM), replacing»(ref-441112-S09232038292011121500000) See «Checking wiring and terminals»(ref-406811-S00386154732011070100000) .

Was a fault detected?

1. YES Refer to «Verification»(ref-406910-S26560361632011070100000)
2. NO Refer to «Checking the component and cable»(ref-406910-S42875838512011070100000)

1. Ignition off. Check the cable between central electronic module (CEM) connector terminal #3B and ignition switch connector 15A terminal #1. Check for a short-circuit to supply voltage. Check for an open-circuit. Other information: The voltage must be 0 V if the key is in position 0 or I To access or replace the central electronic module (CEM) connector, see «Central electronic module (CEM), replacing»(ref-441112-S09232038292011121500000) For the intermediate junction point, see appropriate SYSTEM WIRING DIAGRAM article To connect the breakout box to the control module, see «Connecting the breakout box»(ref-406825-S28150951272011070100000) For further information about signals and other values, see «Signal specification»(ref-406816-S38647568162011070100000) See «Checking wiring and terminals»(ref-406811-S00386154732011070100000) .

Were any faults found in the cable?

1. YES Refer to «Verification»(ref-406910-S26560361632011070100000)
2. NO Refer to «Replacing the ignition switch connector»(ref-406910-S08775324322011070100000)

Try replacing the ignition switch connector according to Steering wheel lock, replacing .

1. Continue Refer to «Verification»(ref-406910-S26560361632011070100000)

HINT: After the repair it is necessary to check that the fault has been rectified.

1. Ignition off.
2. Connect connectors, install components, etc.
3. Ignition off. Check that 15 voltage is OK.

Is voltage on the wire low?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «Information»(ref-406910-S09394393392011070100000)

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.

1. Ignition off. Check central electronic module (CEM) connector D. Check for contact resistance and oxidation. Remedy as necessary. Check for any damage. HINT: If the fault cause is found, reinstall the components, connectors etc. HINT: If the fault cause was not found, do not reconnect the connector before carrying out further fault-tracing. Other information: To replace the connectors for the central electronic module (CEM), see: «Central electronic module (CEM), replacing»(ref-441112-S09232038292011121500000) See «Contents»(ref-406811-S37635188302011070100000)

Was a fault detected?

1. YES Refer to «Verification»(ref-406910-S09418463142011070100000)
2. NO Refer to «Checking the component and cable»(ref-406910-S33667782032011070100000)

1. Ignition off. Check the cable between central electronic module (CEM) connector terminal #D60 and the 50-supply to ignition switch connector terminal #7. Check for an open-circuit. Check for a short-circuit to ground. The voltage must be battery voltage when the key is in the ignition position III. Other information: See «Connecting the breakout box»(ref-406825-S11308929022011070100000) See «Signal specification»(ref-406816-S38647568162011070100000) See «Central electronic module (CEM), replacing»(ref-441112-S09232038292011121500000) See «Contents»(ref-406811-S37635188302011070100000)

Is the voltage the same as battery voltage?

1. YES Refer to «Verification»(ref-406910-S09418463142011070100000)
2. NO Refer to «Replacing the ignition switch»(ref-406910-S41448931172011070100000)

To replace the connector for the ignition switch, see: Steering wheel lock, replacing

1. Continue Refer to «Verification»(ref-406910-S09418463142011070100000)

HINT: After the repair it is necessary to check that the fault has been rectified.

1. Ignition off.
2. Connect connectors, install components, etc.
3. Ignition in starting position. Check that 50 voltage is OK.

Is voltage on the wire high?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «Information»(ref-406910-S40077326152011070100000)

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.

Check connector 54/3 and the connector for the central electronic module (CEM) for contact resistance and oxidation according to Contact resistance and oxidation . Check for loose connections according to Loose connections (terminals) . Remedy if necessary.

Check for any damage.

HINT: If the fault cause is found, reinstall the components, connectors etc.

HINT: If the fault cause is not found, do not reinstall the central electronic module (CEM) before continuing with fault-tracing.

Other information

1. To access the central electronic module (CEM) connector, see «Central electronic module (CEM), replacing»(ref-441112-S09232038292011121500000)
2. For the intermediate connector, see appropriate SYSTEM WIRING DIAGRAM article
3. To connect the breakout box to the control module, see «Connecting the breakout box»(ref-406825-S28150951272011070100000)
4. For further information about signals and other values, see «Signal specification»(ref-406816-S38647568162011070100000)

Was a fault detected?

1. YES OKAY: Troubleshooting has been completed.
2. NO Refer to «Checking the cable»(ref-406910-S09885686582011070100000)

Check the cable between central electronic module connector terminal #20A and the ignition switch connector terminal #50. Check for an open-circuit according to Open-circuit, intermittent faults . Check for a short-circuit to ground according to Short-circuit to ground, intermittent faults .

Other information

1. The voltage must be the same as battery voltage if the key is in position III
2. To access or replace the central electronic module (CEM) connector, see «Central electronic module (CEM), replacing»(ref-441112-S09232038292011121500000)
3. For the intermediate connectors, see appropriate SYSTEM WIRING DIAGRAM article
4. To connect the breakout box, see «Connecting the breakout box»(ref-406825-S28150951272011070100000)
5. For further information about signals and other values, see «Signal specification»(ref-406816-S38647568162011070100000)

1. Continue OKAY: Troubleshooting has been completed.

1. Ignition off. Check connector 54/3 and the connector for the central electronic module (CEM). Check for contact resistance and oxidation. Remedy if necessary. Check for any damage. HINT: If the fault cause is found, reinstall the components, connectors etc. If the fault cause is not found, do not reinstall the central electronic module (CEM) before continuing with fault-tracing. Other information: To access the central electronic module (CEM) connector, see «Central electronic module (CEM), replacing»(ref-441112-S09232038292011121500000) For connector 54/3, see appropriate SYSTEM WIRING DIAGRAM article See «Checking wiring and terminals»(ref-406811-S00386154732011070100000) .

Was a fault detected?

1. YES Refer to «Verification»(ref-406910-S30436176552011070100000)
2. NO Refer to «Checking the component and cable»(ref-406910-S20729126132011070100000)

1. Ignition off. Check the cable between central electronic module (CEM) connector terminal #20A and the ignition switch 50-supply connector terminal #7. Check for an open-circuit. Check for a short-circuit to ground. Other information: The voltage must be the same as battery voltage if the key is in position III To access or replace the central electronic module (CEM) connector, see «Central electronic module (CEM), replacing»(ref-441112-S09232038292011121500000) For the intermediate connector, see appropriate SYSTEM WIRING DIAGRAM article To connect the breakout box to the control module, see «Connecting the breakout box»(ref-406825-S28150951272011070100000) For further information about signals and other values, see «Signal specification»(ref-406816-S38647568162011070100000) See «Checking wiring and terminals»(ref-406811-S00386154732011070100000) .

Is the voltage the same as battery voltage?

1. YES Refer to «Verification»(ref-406910-S30436176552011070100000)
2. NO Refer to «Replacing the ignition switch connector»(ref-406910-S19912410762011070100000)

Try replacing the ignition switch connector according to Steering wheel lock, replacing .

1. Continue Refer to «Verification»(ref-406910-S30436176552011070100000)

HINT: After the repair it is necessary to check that the fault has been rectified.

1. Ignition off.
2. Connect connectors, install components, etc.
3. Ignition in starting position. Check that 50 voltage is OK.

Is voltage on the wire high?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «Information»(ref-406910-S40233298572011070100000)

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.

1. Ignition off. Check central electronic module (CEM) connector D. Check for contact resistance and oxidation. Remedy as necessary. Check for any damage. HINT: If the fault cause is found, reinstall the components, connectors etc. HINT: If the fault cause was not found, do not reconnect the connector before carrying out further fault-tracing. Other information: To replace the connectors for the central electronic module (CEM), see: «Central electronic module (CEM), replacing»(ref-441112-S09232038292011121500000) See «Contents»(ref-406811-S37635188302011070100000)

Was a fault detected?

1. YES Refer to «Verification»(ref-406910-S29208649002011070100000)
2. NO Refer to «Checking the component and cable»(ref-406910-S32185002062011070100000)

1. Ignition off. Check the cable between central electronic module (CEM) connector terminal #D60 and ignition switch connector terminal #7. Check for a short-circuit to supply voltage. The voltage must be 0 V if the key is in position 0, I or II. Other information: See «Connecting the breakout box»(ref-406825-S11308929022011070100000) See «Signal specification»(ref-406816-S38647568162011070100000) See «Central electronic module (CEM), replacing»(ref-441112-S09232038292011121500000) See «Contents»(ref-406811-S37635188302011070100000)

Were any faults found in the cable?

1. YES Refer to «Verification»(ref-406910-S29208649002011070100000)
2. NO Refer to «Replacing the ignition switch»(ref-406910-S24816369932011070100000)

To replace the connector for the ignition switch, see: Steering wheel lock, replacing

1. Continue Refer to «Verification»(ref-406910-S29208649002011070100000)

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

Scheme 319

Scheme 320

Scheme 321

1. Ignition off.
2. Reinstall the connectors, components etc.
3. Turn the ignition key to position I.

Is the voltage OK?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «Information»(ref-406910-S07232293632011070100000)

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.

Check connector 54/3R and the connector for the central electronic module (CEM) for contact resistance and oxidation and remedy according to Contact resistance and oxidation and loose connections according to Loose connections (terminals) .

Check for damage carefully.

HINT: If the fault cause is found, reinstall the components, connectors etc.

HINT: If the fault cause is not found, do not reinstall the central electronic module (CEM) before continuing with fault-tracing.

Other information

1. To access the central electronic module (CEM) connector, see «Central electronic module (CEM), replacing»(ref-441112-S09232038292011121500000) .
2. For the intermediate connector, see appropriate SYSTEM WIRING DIAGRAM article.

Was a fault detected?

1. YES OKAY: Troubleshooting has been completed.
2. NO Refer to «Checking wiring»(ref-406910-S17882156922011070100000)

1. Ignition off. Check the central electronic module (CEM) connector for contact resistance and oxidation. Remedy if necessary. Check for any damage. HINT: If the fault cause is found, reinstall the components, connectors etc. If the fault cause is not found, do not reinstall the central electronic module (CEM) before continuing with fault-tracing. Other information: To access the central electronic module (CEM) connector, see «Central electronic module (CEM), replacing»(ref-441112-S09232038292011121500000) See «Checking wiring and terminals»(ref-406811-S00386154732011070100000) .

Was a fault detected?

1. YES Refer to «Verification»(ref-406910-S34794941272011070100000)
2. NO Refer to «Checking the component and cable»(ref-406910-S01358204072011070100000)

1. Ignition off. Check the cable between central electronic module (CEM) connector terminal #20A and ignition switch connector terminal #50. Check for a short-circuit to supply voltage. Check for an open-circuit. Other information: The voltage must be 0 V if the key is in position 0, I or II To access or replace the central electronic module (CEM) connector, see «Central electronic module (CEM), replacing»(ref-441112-S09232038292011121500000) For the intermediate connector, see appropriate SYSTEM WIRING DIAGRAM article To connect the breakout box to the control module, see «Connecting the breakout box»(ref-406825-S28150951272011070100000) For further information about signals and other values, see «Signal specification»(ref-406816-S38647568162011070100000) See «Checking wiring and terminals»(ref-406811-S00386154732011070100000) .

Were any faults found in the cable?

1. YES Refer to «Verification»(ref-406910-S34794941272011070100000)
2. NO Refer to «Replacing the ignition switch connector»(ref-406910-S26013505852011070100000)

Try replacing the ignition switch connector according to Steering wheel lock, replacing .

1. Continue Refer to «Verification»(ref-406910-S34794941272011070100000)

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

1. Ignition off.
2. Reinstall the connectors, components etc.
3. Turn the ignition key to position I.

Is the voltage OK?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «Information»(ref-406910-S12533595002011070100000)

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 relay

Check that relay 2/29 is installed correctly.

At the same time check relay connection for contact resistance and oxidation as described in Contact resistance and oxidation , and for a loose contact as described in Loose connections (terminals) .

Additional information

1. For interior main relay unit, see «Central electronic module (CEM), replacing»(ref-441112-S09232038292011121500000)

Scheme 322

Is there a fault?

1. YES OKAY: Troubleshooting has been completed.
2. NO Refer to «Replacement of component»(ref-406910-S11516684672011070100000)

1. Ignition off. Check that relay 2/29 is installed correctly. At the same time check relay connection for contact resistance and oxidation as described in «Contact resistance and oxidation»(ref-441113-S31766030992011121500000) . Additional information For interior relay unit, see «Central electronic module (CEM), replacing»(ref-441112-S09232038292011121500000)

Is there a fault?

1. YES Refer to «Verification»(ref-406910-S37798958062011070100000)
2. NO Refer to «Replacing the CEM»(ref-406910-S19111140452011070100000)

Replacing the CEM

Replace the relay.

Additional information

1. For interior relay unit, see «Central electronic module (CEM), replacing»(ref-441112-S09232038292011121500000)

1. Continue Refer to «Verification»(ref-406910-S37798958062011070100000)

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. Click on the VCT2000 symbol. To activate and deactivate the relay, click a number of times on "Start activation" and "End activation" for the current function.

Did the relay click?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «Information»(ref-406910-S06947973612011070100000)

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.

Check that relay 2/29 is installed correctly.

At the same time check relay connection for contact resistance and oxidation as described in Contact resistance and oxidation , and for a loose contact as described in Loose connections (terminals) .

Additional information

1. For interior main relay unit, see «Central electronic module (CEM), replacing»(ref-441112-S09232038292011121500000)

Is there a fault?

1. YES OKAY: Troubleshooting has been completed.
2. NO Refer to «Replacement of component»(ref-406910-S39735245682011070100000)

1. Ignition off. Check that relay 2/29 is correctly installed. At the same time, check the relay terminal for contact resistance and oxidation according to «Contact resistance and oxidation»(ref-441113-S31766030992011121500000) . Other information For relays in the passenger compartment, see «Central electronic module (CEM), replacing»(ref-441112-S09232038292011121500000)

Was a fault detected?

1. YES Refer to «Verification»(ref-406910-S20178194192011070100000)
2. NO Refer to «Replacing the CEM»(ref-406910-S37238569332011070100000)

To replace the relays in the passenger compartment, see Central electronic module (CEM), replacing .

1. Continue Refer to «Verification»(ref-406910-S20178194192011070100000)

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. Click on the VCT2000 symbol. To activate and deactivate the relay, click a number of times on "Start activation" and "End activation" for the current function.

Did the relay click?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «Information»(ref-406910-S22588069262011070100000)

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.

Check that relay 2/101 is correctly installed.

Also check the relay terminals for contact resistance and oxidation according to Contact resistance and oxidation and loose connections according to Loose connections (terminals) .

Other information

1. For the relay box in the passenger compartment, see «Central electronic module (CEM), replacing»(ref-441112-S09232038292011121500000) .

Scheme 323

Was a fault detected?

1. YES OKAY: Troubleshooting has been completed.
2. NO Refer to «Replacing CEM»(ref-406910-S08245508352011070100000)

Replacing CEM

Replace the relay according to Central electronic module (CEM), replacing .

1. Continue Refer to «Checking the relay»(ref-406910-S33725908322011070100000)

If the fault is intermittent, do not verify fault-tracing if the fault does not recur.

It is possible to view the information again, or leave fault-tracing for this diagnostic trouble code (DTC).

1. Ignition off. Check that relay 2/101 is correctly installed. Also check the relay terminals for contact resistance and oxidation according to «Contact resistance and oxidation»(ref-441113-S31766030992011121500000) . Other information For relays in the passenger compartment, see «Central electronic module (CEM), replacing»(ref-441112-S09232038292011121500000) .

Was a fault detected?

1. YES Refer to «Verification»(ref-406910-S30035557002011070100000)
2. NO Refer to «Replacing the CEM»(ref-406910-S02499373142011070100000)

Replace the relay.

Other information

1. For relays in the passenger compartment, see «Central electronic module (CEM), replacing»(ref-441112-S09232038292011121500000) .

1. Continue Refer to «Verification»(ref-406910-S30035557002011070100000)

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. Click on the VCT2000 symbol. To activate and deactivate the relay, click a number of times on "Start activation" and "End activation" for the current function.

Did the relay click?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «Information»(ref-406910-S20927757732011070100000)

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.

Check that relay 2/101 is correctly installed.

Also check the relay terminals for contact resistance and oxidation according to Contact resistance and oxidation and loose connections according to Loose connections (terminals) .

Other information

1. For the relay box in the passenger compartment, see «Central electronic module (CEM), replacing»(ref-441112-S09232038292011121500000) .

Was a fault detected?

1. YES OKAY: Troubleshooting has been completed.
2. NO Refer to «Replacing CEM»(ref-406910-S40849041602011070100000)

Replace the relay.

Other information

1. For the relay box in the passenger compartment, see «Central electronic module (CEM), replacing»(ref-441112-S09232038292011121500000) .

1. Continue Refer to «Information»(ref-406910-S25283529872011070100000)

If the fault is intermittent, do not verify fault-tracing if the fault does not recur.

It is possible to view the information again, or leave fault-tracing for this diagnostic trouble code (DTC).

1. Ignition off. Check that relay 2/101 is correctly installed. Also check the relay terminals for contact resistance and oxidation according to «Contact resistance and oxidation»(ref-441113-S31766030992011121500000) . Other information To replace relays in the passenger compartment, see «Central electronic module (CEM), replacing»(ref-441112-S09232038292011121500000) .

Was a fault detected?

1. YES Refer to «Verification»(ref-406910-S14404079022011070100000)
2. NO Refer to «Replacing the CEM»(ref-406910-S40145739962011070100000)

To replace relays in the passenger compartment, see Central electronic module (CEM), replacing .

1. Continue Refer to «Verification»(ref-406910-S14404079022011070100000)

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. Click on the VCT2000 symbol. To activate and deactivate the relay, click a number of times on "Start activation" and "End activation" for the current function.

Did the relay click?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «Information»(ref-406910-S28612639762011070100000)

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 and replacing the CEM

1. Ignition off
2. Replace the 15i power supply relay
3. Ignition on. Activate and deactivate the relay. The relay must click. If the function is OK, the cause of the fault was a defective relay (short-circuit in the relay). Other information To access and replace the relay, see «Central electronic module (CEM), replacing»(ref-441112-S09232038292011121500000) For further information about the fuses and relays, see the appropriate SYSTEM WIRING DIAGRAM article.

Was the function OK?

1. YES OKAY: Troubleshooting has been completed.
2. NO Refer to «Checking the control module»(ref-406910-S24128000282011070100000)

Scheme 324

1. Ignition off
2. Remove the relay
3. Ignition on. Check the relay coil driver circuit for a short-circuit to supply voltage by measuring the voltage at terminal #2 in the relay base. HINT: The voltage between terminal #2 and ground should be approximately 0 V. Remedy as necessary. Other information To access and replace the relay, see «Central electronic module (CEM), replacing»(ref-441112-S09232038292011121500000) For further information about the fuses and relays, see the appropriate SYSTEM WIRING DIAGRAM article See «Checking wiring and terminals»(ref-406811-S00386154732011070100000) .

1. Continue Refer to «Verification»(ref-406910-S29498590702011070100000)

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. Activate and deactivate the 15i power supply.

Does the relay click at activation and deactivation?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «Information»(ref-406910-S29147074192011070100000)

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.

1. Ignition off
2. Remove the 15i power supply relay. Check the relay base switches. Check for contact resistance and oxidation
3. Install the relay
4. Ignition on. Activate and deactivate the relay. The relay must click. If the function is now OK the fault was caused by a contact fault in the relay base. Other information To access and replace the relay, see «Central electronic module (CEM), replacing»(ref-441112-S09232038292011121500000) For further information about the fuses and relays, see the appropriate SYSTEM WIRING DIAGRAM article See «Checking wiring and terminals»(ref-406811-S00386154732011070100000) .

Was the function OK?

1. YES Refer to «Verification»(ref-406910-S04167982452011070100000)
2. NO Refer to «Replacing the CEM»(ref-406910-S12243938452011070100000)

1. Ignition off
2. Replace the 15i power supply relay
3. Ignition on. Activate and deactivate the relay. The relay must click. If the function is now OK, the cause of the fault was a defective relay (short-circuit to ground or an open-circuit in the relay coil). Other information To access and replace the relay, see «Central electronic module (CEM), replacing»(ref-441112-S09232038292011121500000) For further information about the fuses and relays, see the appropriate SYSTEM WIRING DIAGRAM article.

Was the function OK?

1. YES OKAY: Troubleshooting has been completed.
2. NO Refer to «Checking the control module for open-circuits»(ref-406910-S41841287712011070100000)

Checking the control module for open-circuits

1. Ignition off
2. Remove the 15i power supply relay
3. Ignition on. Check the driver circuit for the relay coil for an open-circuit as follows: activate the relay driver. Measure the voltage between terminals #1 and #2 on the relay base. The voltage between terminals #1 and #2 should be battery voltage. If the value deviates excessively, check the voltage between terminal #2 and the battery voltage and between terminal #1 and ground. Both should equal battery voltage. HINT: Do not forget to check that the power supply to the control module is OK. Other information To access and replace the relay, see «Central electronic module (CEM), replacing»(ref-441112-S09232038292011121500000) For further information about the fuses and relays, see the appropriate SYSTEM WIRING DIAGRAM article See «Checking wiring and terminals»(ref-406811-S00386154732011070100000) .

Was a fault detected?

1. YES Refer to «Verification»(ref-406910-S04167982452011070100000)
2. NO Refer to «Checking the control module for short-circuits»(ref-406910-S18556953002011070100000)

Checking the control module for short-circuits

1. Ignition on. Activate the relay driver. Measure the resistance between terminal #2 and ground when the relay driver is active. The resistance must be low when the relay driver is active. Remedy as necessary. Other information To access and replace the relay, see «Central electronic module (CEM), replacing»(ref-441112-S09232038292011121500000) For further information about the fuses and relays, see the appropriate SYSTEM WIRING DIAGRAM article.

1. Continue Refer to «Verification»(ref-406910-S04167982452011070100000)

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. Activate and deactivate the 15i power supply.

Does the relay click at activation and deactivation?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «Information»(ref-406910-S17506050902011070100000)

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.

Replacing the control module

The diagnostic trouble code (DTC) indicates an internal fault in the central electronic module (CEM) which means that the control module needs to be replaced.

Read off the customer parameters from the control module before it is replaced. Click on the VCT2000 symbol. Make a note of the values.

See Central electronic module (CEM), replacing

1. Continue OKAY: Troubleshooting has been completed.

The diagnostic trouble code (DTC) indicates that the control module has previously registered an intermittent fault, but that the fault is no longer present.

1. Continue OKAY: Troubleshooting has been completed.

The diagnostic trouble code (DTC) indicates an internal fault in the central electronic module (CEM) which means that the control module needs to be replaced.

Read off the customer parameters from the control module before it is replaced. Click on the VCT2000 symbol. Make a note of the values.

Other information

1. See «Central electronic module (CEM), replacing»(ref-441112-S09232038292011121500000)

1. Continue OKAY: Troubleshooting has been completed.

Faulty signal

See Faulty signal

Internal fault. Intermittent fault

See Internal fault. Intermittent fault

Internal fault. Permanent fault

See Internal fault. Permanent fault

Checking the function of the supplemental restraint system module (SRS)

Check the power supply to the control module by turning the ignition to position II.

The SRS (supplemental restraint system) indicator lamp in the driver information module (DIM) must light. The lamp must go out after approximately 7 seconds.

Scheme 325

Does the warning lamp go out?

1. YES Refer to «Checking communication with the supplemental restraint system module (SRS)»(ref-406910-S11173126982011070100000)
2. NO Refer to «Checking the power supply and ground for the supplemental restraint system module (SRS)»(ref-406910-S26019091152011070100000)

Checking the power supply and ground for the supplemental restraint system module (SRS)

For further information about the fuse and terminal pin numbers, see the appropriate SYSTEM WIRING DIAGRAM article.

Checking the power supply

1. Check the fuse in the passenger compartment fusebox for the supplemental restraint system module (SRS). NOTE: If a fuse is blown, check the circuit after the fuse before replacing the fuse. Check for a short-circuit to ground. Then replace the fuse. For further information about the circuit after the fuse, refer to the wiring diagram
2. Check the power supply cable between the X-supply from the ignition switch and the supplemental restraint system module (SRS). Check for an open-circuit
3. Check the power supply cable between the 15-supply and the supplemental restraint system module (SRS). Check for an open-circuit. Check for a short-circuit to ground.

Checking the ground terminal

1. The supplemental restraint system module (SRS) is grounded when it is screwed into place in the car. The resistance between the control module casing and the ground terminal must be 0 ohms.

Remedy as necessary

Other information

1. To access and replace the supplemental restraint system module (SRS) and connector, see «Supplemental restraint system module (SRS), replacing»(ref-406929-S07191846932011070100000)
2. To connect the breakout box, see «Connecting the breakout box»(ref-406837-S31308723212011070100000)
3. With the ignition off and the supplemental restraint system module (SRS) installed, the resistance between the control module casing and the ground terminal must be approximately 0 ohms.
4. For other values, see «Signal specification»(ref-441129-S30568468642011121500000)
5. For information about checking the wiring, see «Checking wiring and terminals»(ref-406811-S00386154732011070100000)

Scheme 326

Was a fault detected?

1. YES Refer to «Checking the function of the supplemental restraint system module (SRS)»(ref-406910-S08631671802011070100000)
2. NO Refer to «Signal missing»(ref-406910-S18169327942011070100000)

Checking communication with the supplemental restraint system module (SRS)

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 supplemental restraint system module (SRS) 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-406910-S18169327942011070100000)

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. Check the power supply to the control module by turning the ignition to position II. The indicator lamp in the driver information module (DIM) must light up. The lamp must go out after approximately 7 seconds.

Does the indicator lamp go out?

1. YES OKAY: Troubleshooting has been completed.
2. NO Refer to «Information»(ref-406910-S17465949792011070100000)

Connect an ohmmeter between respective CAN cable (CAN-L and CAN-H) and voltage supply and between the CAN cables and ground. Turn the contacts and turn the cable harness. The resistance must be infinite or very high (more than 1 Mohms).

HINT: Readings can be taken from one and the same connector if the CAN wiring, voltage supply and ground is prerouted. If possible, measure from the rear of the affected connectors in order to minimize any damage and future loose connections. If this is not possible, use the adapter wiring or loose terminal pin for good contact.

Was a fault detected?

1. YES Refer to «Identifying fault causes in the CAN network»(ref-406910-S19353791242011070100000)
2. NO Refer to «Checking the traffic load on the CAN cables»(ref-406910-S23634261422011070100000)

1. Connect the battery.
2. Ignition on. 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. The load can be checked by reading the average value of the voltage on the CAN cables in relation to ground. The following applies for model year -2004: Connect a voltmeter between CAN-L and ground. The voltage shall be approx. 2. 3 V. Then connect a voltmeter between CAN-H and ground. The voltage shall be approx. 2. 8 V. The following applies for model year 2004-: Connect a voltmeter between CAN-L and ground. The voltage should be approx: V Connect a voltmeter between CAN-H and ground. The voltage should be approx: V NOTE: For vehicles of later model years, normal voltage values lie within a specific interval due to increased traffic between the control modules on the CAN network upon update of the electrical system. HINT: If possible, measure from the rear of the affected connectors so that they are not damaged. Other information See «Battery, disconnecting»(ref-406866-S10988298012011070100000)

Is the value OK?

1. YES Refer to «Information»(ref-406910-S27502032322011070100000)
2. NO Refer to «Identifying a control module in the CAN network»(ref-406910-S17468012282011070100000)

1. Disconnect a control module that disconnects the CAN network (a control module that has four terminals to the CAN network). HINT: For the low speed network, suitable places for disconnecting the network are at the steering wheel module (SWM), the driver information module (DIM) or the climate control module (CCM). In the event of an short-circuit between on of the CAN cables and voltage or ground, the fault can be localized disconnecting a control module that splits the CAN network. Readings can then be taken to determine on which side the fault is on the disconnected control module. Connect an ohmmeter between the CAN cable and voltage supply respectively ground. Take readings from both ends of the CAN networks at the network junction. Twist and bend the cable harness to find any intermittent short-circuits. The resistance must be infinite or very high (more than 1 Mohms). If a fault can be localized in one direction, split the network at a point further on in the CAN network in the direction that the fault was discovered and take a new reading. Try to locate the fault in this way. HINT: A short-circuit between the CAN cables and supply voltage or ground may be in either the wiring or in a control module. Remedy the cables as necessary. If a fault is found on one control module, replace the control module.

1. Continue Refer to «Verification»(ref-406910-S38064885922011070100000)

1. Connect the battery.
2. Ignition on. If the load on the CAN network is too high, this may be due to a control module transmitting faulty messages on the CAN network. This is called 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 fault may occur without any of the control modules storing a diagnostic trouble code (DTC). The voltage can be measured between the CAN cables in order to check the load on the CAN network. The following applies for model year -2004: Connect a voltmeter between the CAN cables. In the event of correct communication on the network, the average value of the voltage must be approximately 0. 5 V (0. 4 V to 0. 6 V). The following applies for model year 2004-:The following applies for model year 2004-: Connect a voltmeter between the CAN cables. During correct CAN network communication, voltage should be about 0. 6-1. 4 V. NOTE: For vehicles of later model years, the normal voltage value is slightly higher due to increased traffic between the control modules on the CAN network upon update of the electrical system. In the event of a communication fault the voltage is significantly higher than the above specified 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. HINT: When the probable faulty control module has been identified, connect and disconnect the supply voltage to the control module a number of times to verify that the fault appears and disappears. NOTE: Do not cut the power to the central electronic module (CEM) unless it is the last control module left to check. The control module that is communicating incorrectly must be replaced. Remedy as necessary. NOTE: After a fault with "interfering" control modules, other control modules may remain in "Limp-Home mode" even when the ignition has been switched off and on several times. To remedy this, disconnect and reconnect the battery negative terminal to restore the control modules to normal function. Other information See «Battery, disconnecting»(ref-406866-S10988298012011070100000)

1. Continue Refer to «Verification»(ref-406910-S38064885922011070100000)

1. Disconnect a control module that disconnects the CAN network (a control module that has four terminals to the CAN network). HINT: For the low speed network, suitable places for disconnecting the network are at the steering wheel module (SWM), the driver information module (DIM) or the climate control module (CCM). In the event of an open-circuit on, or short-circuit between the CAN cables, the fault can be localized by disconnecting a control module that splits the CAN network. Readings can then be taken to determine on which side the fault is on the disconnected control module. Connect an ohmmeter between the CAN cables. Take readings from both ends of the CAN networks at the network junction. Twist and bend the cable harness to find any intermittent short-circuits. Resistance should be 120 ohms. If a fault can be localized in one direction, split the network at a point further on in the CAN network in the direction that the fault was discovered and take a new reading. Try to locate the fault in this way. Remedy the cables as necessary.

1. Continue Refer to «Verification»(ref-406910-S38064885922011070100000)

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

1. Reinstall the connectors, components etc.
2. Ignition on.
3. Erase diagnostic trouble codes by clicking the VCT2000 symbol.
4. Start the car. Allow the vehicle to run for 10 minutes.
5. Read off diagnostic trouble codes (DTCs).

Does the diagnostic trouble code (DTC) for a communication fault recur (CEM-1A5X or CEM-1A6X)?

1. YES Refer to «Information»(ref-406910-S17465949792011070100000)
2. NO OKAY: Troubleshooting has been completed.

Verification shows that the fault is no longer present. The diagnostic trouble code (DTC) was probably caused by an intermittent fault.

Fault-tracing for this diagnostic trouble code (DTC) is not followed by a verification.

You can view the information again or exit fault-tracing for this diagnostic trouble code (DTC).

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 for the supplemental restraint system module (SRS)

Check the power supply to the control module by turning the ignition key to ignition position II.

The SRS (supplemental restraint system) indicator lamp in the driver information module (DIM) must light. The lamp must go out after a few seconds.

Does the warning lamp go out?

1. YES Refer to «Checking communication with the supplemental restraint system module (SRS)»(ref-406910-S22805439852011070100000)
2. NO Refer to «Checking the power supply and ground for the supplemental restraint system module (SRS)»(ref-406910-S32383283042011070100000)

Check that the fuse for the control module is intact.

Check the power supply and ground terminal for the supplemental restraint system module (SRS).

Note. The supplemental restraint system module (SRS) is powered via two power inputs. Check that the control module is powered in all ignition positions according to the instructions below.

Remedy as necessary

Other information

1. See «Checking the supply voltage/ground terminal»(ref-406864-S12182005342011070100000)
2. For information about fuse and terminal numbers, See the appropriate SYSTEM WIRING DIAGRAM article.
3. See «Checking wiring and terminals»(ref-406811-S00386154732011070100000)

Was a fault detected?

1. YES Refer to «Checking the function of the supplemental restraint system module (SRS)»(ref-406910-S41562748332011070100000)
2. NO Refer to «Signal missing»(ref-406910-S05743178892011070100000)

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 supplemental restraint system module (SRS) 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-406910-S05743178892011070100000)

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. Check the power supply to the control module by turning the ignition key to ignition position II. The indicator lamp in the driver information module (DIM) must light up. The lamp must go out after a few seconds.

Does the indicator lamp go out?

1. YES OKAY: Troubleshooting has been completed.
2. NO Refer to «Information»(ref-406910-S37017296142011070100000)

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

For general information about CAN-troubleshooting, see

1. INFORMATION/PRODUCT SPECIFICATIONS/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 transmitting faulty messages on the CAN network. This is called 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 fault may occur without any of the control modules storing a diagnostic trouble code (DTC). 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 that has set the diagnostic trouble code that communicates incorrectly. 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. #3 and #11. 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 certain control modules, diagnostic trouble codes (DTCs) may be stored in other 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 327

1. Continue Refer to «Verification»(ref-406910-S41643141512011070100000)

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

Scheme 328

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. Start the engine. Allow the engine to run at idle speed 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-406910-S37017296142011070100000)
2. NO OKAY: Troubleshooting has been completed.

Scheme 329

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/PRODUCT SPECIFICATIONS/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. #3 and #4 (ground). Measurement is shown in the figure. The resistance should be above 1 kohms. #11 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. #3 and #16 (voltage). Measurement is shown in the figure. The resistance should be above 1 kohms. #11 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 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-406910-S41643141512011070100000)
2. NO Refer to «Checking the amount of traffic on the LS-CAN»(ref-406910-S06755877512011070100000)

Scheme 330

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/PRODUCT SPECIFICATIONS/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. #3 and corresponding connection on relevant control module for CAN-H. The voltage shall be lower than 50 mV. #11 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-406910-S41643141512011070100000)

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 driver door module (DDM)

1. Ignition off. Check that the fuse for the control module is intact. Check the power supply and ground terminal as instructed. Other information: See «Checking the power supply and ground terminals»(ref-406857-S41532284402011070100000) For information about fuse and terminal numbers, See the appropriate SYSTEM WIRING DIAGRAM article. See «Contents»(ref-406811-S37635188302011070100000)

Was a fault detected?

1. YES Refer to «Checking the function of the driver door module (DDM)»(ref-406910-S09083272142011070100000)
2. NO Refer to «Signal missing»(ref-406910-S35445288002011070100000)

Checking the communication with the driver door module (DDM)

HINT: The CAN communication with the control module is probably OK if the control module ID can be read off. The fault is probably intermittent and may therefore be difficult to locate.

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

1. Continue Refer to «Signal missing»(ref-406910-S35445288002011070100000)

Checking the function of the driver door module (DDM)

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 further information about the fuse and terminal pin numbers, See the appropriate SYSTEM WIRING DIAGRAM article. Check the function of the control module by pressing the up and down buttons for the power window mechanism. The window must open or close. Also activate the central locking buttons. The doors must lock and unlock.

Is the function OK?

1. YES OKAY: Troubleshooting has been completed.
2. NO Refer to «Information»(ref-406910-S35908812752011070100000)

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/PRODUCT SPECIFICATIONS/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. #3 and #11. 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 LS-CAN ( ), terminating resistors are located in Upper electronic module (UEM) and Rear electronic module (REM). 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 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-406910-S29757318622011070100000)
2. NO Refer to «Checking short-circuiting to ground/voltage in CAN-net»(ref-406910-S29333462752011070100000)

Checking the amount of traffic on the LS-CAN

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: 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. The load can be checked by reading the average value of the voltage on the CAN cables in relation to ground. For further information, see the appropriate SYSTEM WIRING DIAGRAM article. Measure voltage between the following connections on the OBDII-box/diagnostics socket. #3 and #4 (ground). The voltage should be approx:2,8 - 3,2 V. #11 and #4 (ground). The voltage should be approx:1,8 - 2,2 V. #3 and #11. 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-406910-S31651022822011070100000)
2. NO Refer to «Checking voltage-drop in cable for CAN-H and CAN-L, respectively»(ref-406910-S13337590612011070100000)

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

For general information about CAN-troubleshooting, see

1. INFORMATION/PRODUCT SPECIFICATIONS/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 transmitting faulty messages on the CAN network. This is called 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 fault may occur without any of the control modules storing a diagnostic trouble code (DTC). 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 that has set the diagnostic trouble code that communicates incorrectly. 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. #3 and #11. 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 certain control modules, diagnostic trouble codes (DTCs) may be stored in other 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-406910-S29757318622011070100000)

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. Start the engine. Allow the engine to run at idle speed 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-406910-S35908812752011070100000)
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/PRODUCT SPECIFICATIONS/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. #3 and #4 (ground). Measurement is shown in the figure. The resistance should be above 1 kohms. #11 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. #3 and #16 (voltage). Measurement is shown in the figure. The resistance should be above 1 kohms. #11 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 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-406910-S29757318622011070100000)
2. NO Refer to «Checking the amount of traffic on the LS-CAN»(ref-406910-S27396205352011070100000)

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/PRODUCT SPECIFICATIONS/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. #3 and corresponding connection on relevant control module for CAN-H. The voltage shall be lower than 50 mV. #11 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-406910-S29757318622011070100000)

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.

1. Ignition on. Check the function of the control module by pressing the up and down buttons for the power window mechanism. The window must open or close Also activate the central locking buttons. The doors must lock and unlock.

Is the function OK?

1. YES Refer to «Checking the communication with the driver door module (DDM)»(ref-406910-S32182271092011070100000)
2. NO Refer to «Checking the power supply and ground for the driver door module (DDM)»(ref-406910-S37249546922011070100000)

Scheme 331

1. Ignition off. HINT: For information about fuse numbers and the numbering of terminal pins, see the appropriate wiring diagram for the relevant car model. Check that the fuse for the driver door module (DDM) in the passenger compartment fusebox is intact. Connect a voltmeter between the power supply cable to the control module and ground. The voltage between the control module power cable and ground must be battery voltage when the ignition is off. Check the cable between the control module and ground: the left or right front seat support. Check for a short-circuit to ground. Check for an open-circuit. Other information: To access the driver door module (DDM), see «Driver's door module / passenger door module (DDM/PDM), replacing»(ref-406931-S10848755102011070100000) To connect the breakout box, see «Connecting the breakout box»(ref-406837-S00797040342011070100000) For further information about signals and other values, see «Signal specification»(ref-406858-S16849040092011070100000) To check the wiring and connections, see «Checking wiring and terminals»(ref-406811-S00386154732011070100000) .

Was a fault detected?

1. YES Refer to «Checking the function of the driver door module (DDM)»(ref-406910-S09515094902011070100000)
2. NO Refer to «Signal missing»(ref-406910-S32214940442011070100000)

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 driver door module (DDM) by reading off the control module ID
3. Click on the symbol for VCT2000 to begin reading off

1. Continue Refer to «Signal missing»(ref-406910-S32214940442011070100000)

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 further information about the fuse and terminal pin numbers, see the appropriate wiring diagram. Check the function of the control module by pressing the up and down buttons for the power window mechanism. The window must open or close Also activate the central locking buttons. The doors must lock and unlock.

Is the function OK?

1. YES OKAY: Troubleshooting has been completed.
2. NO Refer to «Information»(ref-406910-S38033932272011070100000)

1. Disconnect the battery negative lead. The network must not be powered when taking resistance readings. Otherwise an incorrect value may be obtained.
2. Connect the adapter wiring to 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. When taking readings on the low speed network When taking readings on the low speed network the adapter wiring should be connected to the Central electronic module (CEM) and readings taken from there. Readings can even be taken in the connector for the Power seat module (PSM). The advantage of the adapter wiring to the Central electronic module (CEM) is that all control module can be connected in the network when taking readings and access can be gained to both the high speed and low speed networks. The resistance reading only measures the main arteries in the low speed network, not the junctions that exist for different control modules. For further information, see the appropriate wiring diagram. When taking readings on the high speed network When taking readings on the high speed network the adapter wiring should be connected to the Engine control module (ECM) and readings taken from there. The Engine control module (ECM) must be connected. This resistance reading only measures the main arteries in the high speed network. For further information, see the appropriate wiring diagram. Connect an ohmmeter to the terminals for CAN-L and CAN-H on the relevant network. Turn the contacts and turn the cable harness. Resistance must be approximately 60 ohms. NOTE: Resistance will only be 60 ohms if the main artery of the CAN network is whole and the network is connected. If the main artery of the CAN network is split somewhere and a reading is taken between the CAN cables, resistance will be 120 ohms. For further information, see the appropriate wiring diagram. Other information See «Battery, disconnecting»(ref-406866-S10988298012011070100000) See «Connecting the breakout box»(ref-406825-S28150951272011070100000) See «Checking wiring and terminals»(ref-406811-S00386154732011070100000)

Is the value OK?

1. YES Refer to «Checking a short-circuit in CAN cables»(ref-406910-S23002059332011070100000)
2. NO Refer to «Identifying fault causes in the CAN network»(ref-406910-S11097524192011070100000)

Connect an ohmmeter between respective CAN cable (CAN-L and CAN-H) and voltage supply and between the CAN cables and ground. Turn the contacts and turn the cable harness. The resistance must be infinite or very high (more than 1 Mohms).

HINT: Readings can be taken from one and the same connector if the CAN wiring, voltage supply and ground is pre-routed. If possible, measure from the rear of the affected connectors in order to minimize any damage and future loose connections. If this is not possible, use the adapter wiring or loose terminal pin for good contact.

Was a fault detected?

1. YES Refer to «Identifying fault causes in the CAN network»(ref-406910-S15247160442011070100000)
2. NO Refer to «Checking the traffic load on the CAN cables»(ref-406910-S03596243912011070100000)

1. Connect the battery.
2. Ignition on. 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. The load can be checked by reading the average value of the voltage on the CAN cables in relation to ground. The following applies for model year -2004: Connect a voltmeter between CAN-L and ground. The voltage shall be approx. 2. 3 V. Then connect a voltmeter between CAN-H and ground. The voltage shall be approx. 2. 8 V. The following applies for model year 2004-: Connect a voltmeter between CAN-L and ground. The voltage should be approx: V Connect a voltmeter between CAN-H and ground. The voltage should be approx: V NOTE: For vehicles of later model years, normal voltage values lie within a specific interval due to increased traffic between the control modules on the CAN network upon update of the electrical system. HINT: If possible, measure from the rear of the affected connectors so that they are not damaged. Other information See «Battery, disconnecting»(ref-406866-S10988298012011070100000)

Is the value OK?

1. YES Refer to «Information - intermittent fault»(ref-406910-S08743017992011070100000)
2. NO Refer to «Identifying a control module in the CAN network»(ref-406910-S06404035462011070100000)

1. Disconnect a control module that disconnects the CAN network (a control module that has four terminals to the CAN network). HINT: For the low speed network, suitable places for disconnecting the network are at the steering wheel module (SWM), the driver information module (DIM) or the climate control module (CCM). In the event of an short-circuit between on of the CAN cables and voltage or ground, the fault can be localized disconnecting a control module that splits the CAN network. Readings can then be taken to determine on which side the fault is on the disconnected control module. Connect an ohmmeter between the CAN cable and voltage supply respectively ground. Take readings from both ends of the CAN networks at the network junction. Twist and bend the cable harness to find any intermittent short-circuits. The resistance must be infinite or very high (more than 1 Mohms). If a fault can be localized in one direction, split the network at a point further on in the CAN network in the direction that the fault was discovered and take a new reading. Try to locate the fault in this way. HINT: A short-circuit between the CAN cables and supply voltage or ground may be in either the wiring or in a control module. Remedy the cables as necessary. If a fault is found on one control module, replace the control module.

1. Continue Refer to «Verification»(ref-406910-S28135058922011070100000)

1. Connect the battery.
2. Ignition on. If the load on the CAN network is too high, this may be due to a control module transmitting faulty messages on the CAN network. This is called 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 fault may occur without any of the control modules storing a diagnostic trouble code (DTC). The voltage can be measured between the CAN cables in order to check the load on the CAN network. The following applies for model year -2004: Connect a voltmeter between the CAN cables. In the event of correct communication on the network, the average value of the voltage must be approximately 0. 5 V (0. 4 V to 0. 6 V). The following applies for model year 2004-:The following applies for model year 2004-: Connect a voltmeter between the CAN cables. During correct CAN network communication, voltage should be about 0. 6-1. 4 V. NOTE: For vehicles of later model years, the normal voltage value is slightly higher due to increased traffic between the control modules on the CAN network upon update of the electrical system. In the event of a communication fault the voltage is significantly higher than the above specified 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. HINT: When the probable faulty control module has been identified, connect and disconnect the supply voltage to the control module a number of times to verify that the fault appears and disappears. NOTE: Do not cut the power to the central electronic module (CEM) unless it is the last control module left to check. The control module that is communicating incorrectly must be replaced. Remedy as necessary. NOTE: After a fault with "interfering" control modules, other control modules may remain in "Limp-Home mode" even when the ignition has been switched off and on several times. To remedy this, disconnect and reconnect the battery negative terminal to restore the control modules to normal function. Other information See «Battery, disconnecting»(ref-406866-S10988298012011070100000)

1. Continue Refer to «Verification»(ref-406910-S28135058922011070100000)

1. Disconnect a control module that disconnects the CAN network (a control module that has four terminals to the CAN network). HINT: For the low speed network, suitable places for disconnecting the network are at the steering wheel module (SWM), the driver information module (DIM) or the climate control module (CCM). In the event of an open-circuit on, or short-circuit between the CAN cables, the fault can be localized by disconnecting a control module that splits the CAN network. Readings can then be taken to determine on which side the fault is on the disconnected control module. Connect an ohmmeter between the CAN cables. Take readings from both ends of the CAN networks at the network junction. Twist and bend the cable harness to find any intermittent short-circuits. Resistance should be 120 ohms. If a fault can be localized in one direction, split the network at a point further on in the CAN network in the direction that the fault was discovered and take a new reading. Try to locate the fault in this way. Remedy the cables as necessary.

1. Continue Refer to «Verification»(ref-406910-S28135058922011070100000)

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

1. Reinstall the connectors, components etc.
2. Ignition on.
3. Erase diagnostic trouble codes by clicking the VCT2000 symbol.
4. Start the car. Allow the vehicle to run for 10 minutes.
5. Read off diagnostic trouble codes (DTCs).

Does the diagnostic trouble code (DTC) for a communication fault recur (CEM-1A5X or CEM-1A6X)?

1. YES Refer to «Information»(ref-406910-S38033932272011070100000)
2. NO OKAY: Troubleshooting has been completed.

Verification shows that the fault is no longer present. The diagnostic trouble code (DTC) was probably caused by an intermittent fault.

Fault-tracing for this diagnostic trouble code (DTC) is not followed by a verification.

You can view the information again or exit fault-tracing for this diagnostic trouble code (DTC).

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.