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Contents

Wiring diagrams Section: Testing & Diagnostics

Engine Performance Diagnostic Trouble Code (DTC) Diagnostics - 1 of 14 (Convertible): Diagnosis
Engine Performance Diagnostic Trouble Code (DTC) Diagnostics - 1 of 14 (Convertible): Wiring
Engine Performance Diagnostic Trouble Code (DTC) Diagnostics - 1 of 14 (Convertible): Other

Engine Performance Diagnostic Trouble Code (DTC) Diagnostics - 2 of 14 (Convertible): Diagnosis
Engine Performance Diagnostic Trouble Code (DTC) Diagnostics - 2 of 14 (Convertible): Removal & Installation
Engine Performance Diagnostic Trouble Code (DTC) Diagnostics - 2 of 14 (Convertible): Wiring
Engine Performance Diagnostic Trouble Code (DTC) Diagnostics - 2 of 14 (Convertible): Other

Engine Control Module (ECM) DTC Index - B5234T3 (Convertible)

Engine Control Module (ECM) DTC Index - B5244T (Convertible)

Engine Control Module (ECM) Diagnostic Trouble Code (DTC) Index - (B5234T3) (Coupe)

Engine Control Module (ECM) Diagnostic Trouble Code (DTC) Index - B5244T (Coupe)

All sections

Engine Performance Diagnostic Trouble Code (DTC) Diagnostics - 7 of 7 (Coupe): Other Volvo C70 I

Testing & Diagnostics 10 illustrations ~15443 words

Checking components

Signal too high/signal too low. Permanent fault

Check the cable between Engine Control Module (ECM) terminal #B15 and clutch pedal position sensor terminal #2 for open circuit, short circuit to supply voltage or short circuit to ground depending on the type of fault detected. Check the ground cable between Engine Control Module (ECM) terminal #B4 and clutch pedal position sensor terminal #4 for open circuit, short circuit to supply voltage or short circuit to ground depending on the type of fault detected. Check the resistance between clutch pedal position sensor terminals #2 and #4. Fault trace and remedy as necessary.

Signal too high/signal too low. Intermittent fault

Use the diagnostic trouble codes' frozen values as well as the counters, to determine the driving conditions when the problem was detected the first time and how often the problem has occurred. The values show the problem's current status and how intermittent the problem is. The operating conditions can be, for example, whether the engine was running, what the speed of the vehicle was and what the battery voltage in the system was. This information can facilitate searching for an intermittent fault. If the fault was stored at a battery voltage lower than 10 V with engine speed at 0 RPM, this indicates that the fault may have occurred when the engine was started. This, in turn, indicates that the battery's charging status is not OK.

Check the battery status.

Faulty signal. Permanent or intermittent.

For markets where upgraded software, released during year 2006 or later, is available, the solution may be to download the upgraded software. It is no longer necessary to store a diagnostic trouble code for this type of fault. Thus, this fault type has been disabled in the upgraded software. For other markets, check the clutch pedal position sensor's installation, cables and connectors for contact resistance and oxidation. Check that the clutch pedal position sensor has the right resistance.

HINT: Using VIDA vehicle communication, check that the parameter "Clutch pedal position" indicates correct values. There are other parameters that can be of help when fault tracing and verifying this diagnostic trouble code. To aid fault tracing, use Component specifications when measuring and checking relevant components and use Wiring diagram, Signal description and Breakout box to measure and control signals to and front the control module or its components.

For markets where upgraded software, released during year 2006 or later, is available, the solution may be to download the upgraded software. Since detection time has been increased from 0.16 to 5 seconds, the upgraded software will be much more tolerant to short, intermittent disruptions.

Remedy as necessary.

Other information

To connect the breakout box, see «Connecting the breakout box»(ref-408435-S12899753102011071200000) .
For information about signals, see «Signal specification»(ref-408451-S42269556162011071200000) .
See «Identifying upgraded software ECM/ETM»(ref-438955-S16861622552011120700000)
See «Checking wiring and terminals»(ref-438953-S20310262912011120700000)

CAUTION

In order for Electronic Throttle Module (ETM) to reset any reconfigurations as well as delete internally stored problems, the following must be performed

Ignition off, wait three minutes so that the main relay / system relay releases the voltage feed to, among other, Electronic Throttle Module (ETM).
Then turn on the ignition and turn it off again.
Wait another three minutes, but if the electric cooling fan is running you have to wait another two minutes after the cooling fan has stopped, to ensure that Electronic Throttle Module (ETM) is shut off correctly.

If this is not done correctly, diagnostic trouble codes may remain even after deleting diagnostic trouble codes and any reconfiguration may remain, despite the problem being fixed.

Scheme 1049

Continue Refer to «Information»(ref-408517-S35417575882011071200000)

Fault-tracing information

In case of this defect, troubleshooting is not followed by verification.

The information can be displayed again or the fault-tracing for this fault can be interrupted.

Signal too high. Intermittent fault

See Signal too high. Intermittent fault

Signal missing. Permanent or intermittent fault.

Using VIDA vehicle communication, check the function of the brake light switch by reading off the parameters "Brake light switch" and "Brake pedal position". When the brake pedal is depressed, the parameter "Brake light switch" should indicate that the switch is activated when the parameter "Brake pedal position" is greater than 32.8% (1.6 V).

Diagnostic trouble code ECM-9400 will be stored in the Engine Control Module (ECM) if the brake light switch has not closed when the brake pedal is depressed and brake pedal position is less than 32.8% (1.6 V) for longer than 0.16 seconds.

If the brake light switch and brake pedal position sensor appear to be working properly, but the brake light switch closes at the wrong time, check the attachment of the brake light switch and the brake pedal position sensor and check that the pedal assembly seems OK.

If the brake light switch does not close when the brake pedal is depressed, check the brake light switch's cables, connectors and voltage supply (battery voltage) to brake light switch terminal #4.

When the brake pedal is depressed (switch closed), brake light switch terminal #3 and Engine Control Module (ECM) terminal #B26 should have battery voltage.

If diagnostic trouble code ECM-9400, No signal, Intermittent fault, is stored but no fault is found, the solution could be to download the upgraded software (only for markets where upgraded software (released 2006 or later) is available). Since detection time has been increased from 0.16 to 2 seconds and the fault must be repeated during 30 consecutive brakings, the upgraded software will be much more tolerant to short, intermittent disruptions.

Note. The upgraded software has adjusted limits for the fault type No signal. The diagnostic trouble code is stored if the brake light switch is not closed when the brake pedal is depressed, brake pedal position is less than 55.9% (2.8 V) for longer than 2 seconds and this is repeated for 30 consecutive brakings.

The diagnostic trouble code can also be stored if the brake light switch is closed when the brake pedal is released. For this test an adapted brake pedal position sensor value is used, that is, the control module adapts the signal so that it always shows 0 % (0 V) at released pedal, which is different from other tests where the direct signal from the sensor is used. This parameter is not accessible in VIDA. By checking what the parameter "Brake pedal position" indicates when the pedal is released and then subtracting the value from the value indicated when the brake light switch is closed, one can estimate the size of the adapted value.

For example, if "Brake pedal position, volts" is 3.10 V when the pedal is released and 2.91 V when the brake light switch closes, the adapted value is 0.19 V (3.10-2.91) when the brake light switch closes. The diagnostic trouble code will be stored if the brake light switch is closed when the adapted value is less than 2.7% (0.14 V) for longer than 2 seconds and this is repeated for 30 consecutive brakings.

HINT: Using VIDA vehicle communication, check that the parameters "Brake pedal position, volts" and "Brake light switch" indicate correct values. To aid fault tracing, use Component specifications when measuring and checking relevant components and use Wiring diagram, Signal description and Breakout box to measure and control signals to and front the control module or its components.

Remedy as necessary

Other information

To connect the breakout box and access the control module, see «Connecting the breakout box»(ref-408435-S12899753102011071200000)
For information about signals, see «Signal specification»(ref-438954-S05832475042011120700000)
For the resistance values, see below. See «Brake pedal sensor»(ref-439005-S27555596072011120700000)
See «Identifying upgraded software ECM/ETM»(ref-438955-S16861622552011120700000)
See «Checking wiring and terminals»(ref-438953-S20310262912011120700000)

CAUTION

In order for Electronic Throttle Module (ETM) to reset any reconfigurations as well as delete internally stored problems, the following must be performed

Ignition off, wait three minutes so that the main relay / system relay releases the voltage feed to, among other, Electronic Throttle Module (ETM).
Then turn on the ignition and turn it off again.
Wait another three minutes, but if the electric cooling fan is running you have to wait another two minutes after the cooling fan has stopped, to ensure that Electronic Throttle Module (ETM) is shut off correctly.

If this is not done correctly, diagnostic trouble codes may remain even after deleting diagnostic trouble codes and any reconfiguration may remain, despite the problem being fixed.

Scheme 1050

Scheme 1051

Continue Refer to «Information»(ref-408517-S19795946122011071200000)

In case of this defect, troubleshooting is not followed by verification.

The information can be displayed again or the fault-tracing for this fault can be interrupted.

See Fault-tracing information

Signal too high/signal too low. Permanent fault

Check resistance between the connections for brake pedal position sensor terminals #1 and #2.

Depending on the type of fault the detected diagnostic trouble code indicates, check the signal cable between Engine Control Module (ECM) terminal #B16 and brake pedal position sensor terminal #1 for open circuit, short circuit to supply voltage or short circuit to ground.

Check the ground cable between Engine Control Module (ECM) terminal #B4 and brake pedal position sensor terminal #2 for open circuit, short circuit to supply voltage or short circuit to ground.

Signal too high/signal too low. Intermittent fault

If for example the trouble code was stored when battery voltage was low and engine speed was equal to 0 RPM, it could indicate that the fault arose when the vehicle was stationary with the ignition on for a long period, thereby draining the battery, or that the fault arose when the customer was attempting to start the vehicle.

For markets where the upgraded software, released during 2006 or later, is available, the solution may be to load the upgraded software. Since detection time has been increased from 0.16 to 2 seconds, the upgraded software will be more tolerant to short, intermittent disruptions.

Remedy as necessary.

Other information

To connect the breakout box, see «Connecting the breakout box»(ref-408435-S12899753102011071200000)
With the ignition on and the brake pedal sensor connector disconnected, the voltage between clutch pedal position sensor terminal #1 and ground must be approximately 5 V
When the clutch pedal position sensor connector is disconnected, the brake pedal sensor #4 must be connected to ground
For information about signals, see «Signal specification»(ref-438954-S05832475042011120700000)
See «Checking wiring and terminals»(ref-438953-S20310262912011120700000)
For the resistance values, see below. See «Brake pedal sensor»(ref-439005-S27555596072011120700000)
See «Identifying upgraded software ECM/ETM»(ref-438955-S16861622552011120700000)

CAUTION

In order for Electronic Throttle Module (ETM) to reset any reconfigurations as well as delete internally stored problems, the following must be performed

Ignition off, wait three minutes so that the main relay / system relay releases the voltage feed to, among other, Electronic Throttle Module (ETM).
Then turn on the ignition and turn it off again.
Wait another three minutes, but if the electric cooling fan is running you have to wait another two minutes after the cooling fan has stopped, to ensure that Electronic Throttle Module (ETM) is shut off correctly.

If this is not done correctly, diagnostic trouble codes may remain even after deleting diagnostic trouble codes and any reconfiguration may remain, despite the problem being fixed.

Scheme 1052

Continue Refer to «Information»(ref-408517-S32210002692011071200000)

In case of this defect, troubleshooting is not followed by verification.

The information can be displayed again or the fault-tracing for this fault can be interrupted.

See Fault-tracing information

In case of this defect, troubleshooting is not followed by verification.

The information can be displayed again or the fault-tracing for this fault can be interrupted.

Faulty signal

See Faulty signal

Check, using the diagnostic trouble code (DTC) statuses, if the fault is intermittent or permanent.

Permanent fault

Check the cable between Engine Control Module (ECM) terminal #B25 and accelerator pedal position sensor terminal #2 for open circuit, short circuit to supply voltage or short circuit to ground depending on the type of fault detected. In conjunction with this, check the cable between Engine Control Module (ECM) terminal #A56 and Electronic Throttle Module (ETM) terminal #1 since #B25 and #A56 are internally connected in the Engine Control Module (ECM) and a short circuit on #A56 will generate this diagnostic trouble code.

Intermittent fault

Check whether the Engine Control Module (ECM) has stored any other diagnostic trouble codes that indicate a fault in the pulse width modulated (PWM) signal from the accelerator pedal position sensor. If trouble code ECM-9520, Faulty signal, is stored together with ECM-985F and ECM-9180, but ECM-959F is not stored, one can assume that the fault occurred for more than 0.05 seconds but less than 0.1 seconds.

If ECM-9180 is stored together with ECM-9520 Faulty signal and ECM-958F, one can assume that the fault occurred for more than 0.1 seconds but less than 0.4 seconds.

If ECM-959F is stored together with ECM-9520, Faulty signal, ECM-9180 and ECM-958F, one can assume that the fault occurred for more than 0.4 seconds.

If diagnostic trouble codes ECM-9520, ECM-9180 and/or ECM-958F occur together with diagnostic trouble codes that indicate an electrical fault in the injectors, EVAP valve and/or turbo control valve, it indicate that there may be a problem with the 12-volt supply from the system relay. Use the diagnostic trouble code's frozen values and the counter to determine if the fault may have been stored at the same time.

HINT: Using VIDA vehicle communication, check that the parameter "Accelerator pedal, PWM" indicates correct values. There are other parameters that can be of help when fault tracing and verifying this diagnostic trouble code. To aid fault tracing, use Component specifications when measuring and checking relevant components and use Wiring diagram, Signal description and Breakout box to measure and control signals to and front the control module or its components.

For markets where upgraded software, released during year 2006 or later, is available, the solution may be to download the upgraded software. Since detection time has been increased from 0.05 to 0.7 seconds, the upgraded software will be more tolerant to short, intermittent disruptions.

Remedy as necessary

Other information

To connect the breakout box, see «Connecting the breakout box»(ref-408435-S12899753102011071200000) .
To access/replace the accelerator pedal (AP) position sensor, see «Replacing the accelerator pedal module»(ref-408444-S34082194572011071200000) .
For information about signals, see «Signal specification»(ref-408451-S42269556162011071200000) .
See «Identifying upgraded software ECM/ETM»(ref-438955-S16861622552011120700000)
See «Checking wiring and terminals»(ref-438953-S20310262912011120700000)

CAUTION

In order for Electronic Throttle Module (ETM) to reset any reconfigurations as well as delete internally stored problems, the following must be performed: Ignition off, wait three minutes so that the main relay / system relay releases the voltage feed to, among other, Electronic Throttle Module (ETM). Then turn on the ignition and turn it off again. Wait another three minutes. If the electric cooling fan is running, you have to wait another two minutes after the electric cooling fan has stopped, to make sure that Electronic Throttle Module (ETM) has been shut off correctly. If this is not done correctly, diagnostic trouble codes may remain even after deleting diagnostic trouble codes and any reconfiguration may remain, despite the problem being fixed.

Scheme 1053

Scheme 1054

Continue Refer to «Information»(ref-408517-S30474999742011071200000)

In case of this defect, troubleshooting is not followed by verification.

The information can be displayed again or the fault-tracing for this fault can be interrupted.

See Faulty signal

If diagnostic trouble code (DTC) ECM-9540 is stored together with ECM-9530, there is probably a problem with the 5 volt supply to the accelerator pedal position sensor's analogue sensor. Fault-trace according to ECM-9540. Otherwise, continue as follows.

Check, using the diagnostic trouble code (DTC) statuses, if the fault is intermittent or permanent.

Signal too high. Permanent fault

Check the cable between the Engine Control Module (ECM) terminal #B17 and accelerator pedal position sensor terminal #5. Check for a short circuit to supply voltage.

Signal too low. Permanent fault

Check the cable between the Engine Control Module (ECM) terminal #B17 and accelerator pedal position sensor terminal #5. Check for an open circuit and short circuit to ground. Also check the cable between Engine Control Module (ECM) terminal #B9 and accelerator pedal position sensor terminal #6. Check for open circuit. This is because an open-circuit in the 5 V supply can cause this diagnostic trouble code (DTC) to be stored.

Intermittent fault

Check the battery status.

HINT: Check, using VIDA vehicle communication, that the parameter "Accelerator pedal, PWM (%)" shows the correct values. To aid fault tracing, use Component specifications when measuring and checking relevant components and use Wiring diagram, Signal description and Breakout box to measure and control signals to and front the control module or its components.

For markets where upgraded software, released during year 2006 or later, is available, the solution may be to download the upgraded software. As the detection time has increased from 0.1 to 0.4 seconds, the upgraded software becomes more tolerant towards short intermittent interference among other things.

Remedy as necessary.

Other information

To connect the breakout box, see «Connecting the breakout box»(ref-408435-S12899753102011071200000) .
To access/replace the accelerator pedal (AP) position sensor, see «Replacing the accelerator pedal module»(ref-408444-S34082194572011071200000) .
Accelerator pedal (AP) position sensor #5 transmits an analog signal that varies between approximately 0.45 V and approximately 4.5 V depending on accelerator pedal (AP) position.
Accelerator pedal (AP) position sensor #6 is power supply (5 V)
Accelerator pedal (AP) position sensor #4 is a signal ground.
For information about signals on 5-cyl, see «Signal specification»(ref-438954-S05832475042011120700000) .
See «Identifying upgraded software ECM/ETM»(ref-438955-S16861622552011120700000)
See «Checking wiring and terminals»(ref-438953-S20310262912011120700000)

CAUTION

In order for Electronic Throttle Module (ETM) to reset any reconfigurations as well as delete internally stored problems, the following must be performed

Ignition off, wait three minutes so that the main relay / system relay releases the voltage feed to, among other, Electronic Throttle Module (ETM).
Then turn on the ignition and turn it off again.
Wait another three minutes. If the electric cooling fan is running, you have to wait another two minutes after the electric cooling fan has stopped, to make sure that Electronic Throttle Module (ETM) has been shut off correctly.

If this is not done correctly, diagnostic trouble codes may remain even after deleting diagnostic trouble codes and any reconfiguration may remain, despite the problem being fixed.

Continue Refer to «Information»(ref-408517-S00097638362011071200000)

In case of this defect, troubleshooting is not followed by verification.

The information can be displayed again or the fault-tracing for this fault can be interrupted.

Signal too high/signal too low

See Signal too high/signal too low

Check, using the diagnostic trouble code (DTC) statuses, if the fault is intermittent or permanent.

Signal too high. Permanent fault

Check the cable between Engine Control Module (ECM) terminal #B9 and accelerator pedal position sensor terminal #6 for short circuit to supply voltage.

Signal too low. Permanent fault

Check the cable between Engine Control Module (ECM) terminal #B9 and accelerator pedal position sensor terminal #6 for short circuit to ground.

Intermittent fault

Check the battery status.

For markets where the upgraded software, released during 2006 or later, is available, the solution may be to load the upgraded software. As the detection time has increased from 0.1 to 0.4 seconds, the upgraded software becomes more tolerant towards short intermittent interference among other things.

Remedy as necessary.

Other information

To connect the breakout box, see «Connecting the breakout box»(ref-408435-S12899753102011071200000) .
To access/replace the accelerator pedal (AP) position sensor, see «Replacing the accelerator pedal module»(ref-408444-S34082194572011071200000) .
For information about signals on 5-cyl, see «Signal specification»(ref-438954-S05832475042011120700000) .
See «Identifying upgraded software ECM/ETM»(ref-438955-S16861622552011120700000)
See «Checking wiring and terminals»(ref-438953-S20310262912011120700000)

CAUTION

Continue Refer to «Information»(ref-408517-S18916344942011071200000)

In case of this defect, troubleshooting is not followed by verification.

The information can be displayed again or the fault-tracing for this fault can be interrupted.

Level too low

See Level too low

Checking the status

HINT: If diagnostic trouble code (DTC) ECM-9520 or ECM-9530 is stored in the Engine Control Module (ECM), these diagnostic trouble codes (DTCs) must be fault-traced first.

Scheme 1055

Scheme 1055: Checking the status

Scheme 1056

Ignition on. Check whether the fault is permanent or intermittent. Read off the analog signal and the pulse width modulation (PWM) signal from the accelerator pedal (AP) position sensor. Check that the difference between the signals is not more than approximately 4%. Check that the value is between 6-9% with unaffected accelerator pedal (AP) and between 85-90% with the accelerator pedal (AP) fully depressed. Check the signals throughout the measurement range of the accelerator pedal (AP) position sensor (from completely released to completely depressed). Make the check using slow movements of the accelerator pedal (AP). The fault is intermittent if the signals are correct. HINT: A defective accelerator pedal (AP) position sensor is indicated if any of the returned signals deviates at a specific accelerator pedal (AP) angle. Other information See «Information about combined diagnostic trouble codes (DTCs)»(ref-438954-S03262982102011120700000)

Continue Refer to «Checking components»(ref-408517-S35423168382011071200000)

Check whether the Engine Control Module (ECM) has stored any other diagnostic trouble codes that indicate a fault in the pulse width modulated (PWM) signal or the analogue signal from the accelerator pedal position sensor.

If ECM-9180, ECM-9520, ECM-9530 and/or ECM-9540 are stored, these diagnostic trouble codes are to be fault traced first. Otherwise, continue as follows.

Using the diagnostic trouble code counter, check whether the fault is intermittent or permanent. Compare the parameters "Accelerator pedal, Analogue" and "Accelerator pedal, PWM". These should under no circumstances differ by more than 5% unless the analogue signal is undergoing change, e.g. during throttle application, when a large deviation between the two signals is permitted.

If the diagnostic trouble code (DTC) is permanent

Search for a fault that could cause any of the signals to be faulty yet still within the electrical fault limits. Check the cables and connections between the accelerator pedal position sensor and the Engine Control Module (ECM) for contact resistance and corrosion.

Check whether there is any potential difference for ground connections and voltage supplies between the Engine Control Module (ECM) and the accelerator pedal position sensor.

Check the cables and connections between the grounding point for the system relay and the accelerator pedal position sensor.

If the diagnostic trouble code (DTC) is intermittent

Use the diagnostic trouble codes' frozen values as well as the counters, to determine the driving conditions when the problem was detected the first time and how often the problem has occurred. The values show the problem's current status and how intermittent the problem is. The operating conditions can be, for example, whether the engine was running, what the speed of the vehicle was and what the battery voltage in the system was. This information can facilitate searching for an intermittent fault. If the trouble code was stored when battery voltage was less than 10.5 V and engine speed was 0 RPM, it indicates that the fault may have occurred when the engine was started. This, in turn, indicates that the battery's charging status is not OK.

Check the battery status.

HINT: Using VIDA vehicle communication, check that the parameters "Accelerator pedal, PWM", "Accelerator pedal, PWM (via ETM)" and "Accelerator pedal, Analogue" indicate correct values. To aid fault tracing, use Component specifications when measuring and checking relevant components and use Wiring diagram, Signal description and Breakout box to measure and control signals to and front the control module or its components.

When ECM-958F is stored, the frozen values often indicate that the fault occurred when battery voltage was less than 12 V and engine speed was close to 0 RPM. If these operating conditions are found in the vehicle and upgraded software is available (released 2006 or later), the solution is to download the upgraded software. The upgraded software requires engine speed to be greater than 600 RPM for the test to be active.

Upgraded software could also be the solution if the trouble code was stored when the engine was running since detection time has been increased from 0.4 to 0.7 seconds. The upgraded software will also be much more tolerant to short, intermittent disruptions. If upgraded software is not available and the frozen values indicate that the fault occurred when battery voltage was low and engine speed was close to 0 RPM, fault tracing should focus on checking the vehicle's power supply, especially battery charge status.

Remedy as necessary.

Other information

To access or replace the system relay, see the location of components
To access or replace the accelerator pedal (AP) position sensor: «Replacing the accelerator pedal module»(ref-408444-S34082194572011071200000)
See «Checking wiring and terminals»(ref-438953-S20310262912011120700000)
See «Identifying upgraded software ECM/ETM»(ref-438955-S16861622552011120700000)
See «Checking wiring and terminals»(ref-438953-S20310262912011120700000)

CAUTION

In order for Electronic Throttle Module (ETM) to reset any reconfigurations as well as delete internally stored problems, the following must be performed

Turn off the ignition and then wait three minutes for the main relay or system relay to release the voltage feed to, among others, Electronic Throttle Module (ETM).
Then turn on the ignition and turn it off again.
Wait another three minutes, but if the electric cooling fan is running you have to wait another two minutes after the cooling fan has stopped, to ensure that Electronic Throttle Module (ETM) is shut off correctly.

If this is not done correctly, diagnostic trouble codes may remain even after deletion of diagnostic trouble codes as well as any reconfiguration, despite the problem being fixed.

Continue Refer to «Information»(ref-408517-S19448662712011071200000)

In case of this defect, troubleshooting is not followed by verification.

The information can be displayed again or the fault-tracing for this fault can be interrupted.

See Faulty signal

Note. If diagnostic trouble code (DTC) ECM-958F is stored, do not carry out the following fault-tracing.

Scheme 1057

Scheme 1057: Checking the status

Start the engine. Check whether the fault is permanent or intermittent. Read off the pulse width modulation (PWM) signal from the accelerator pedal (AP) position sensor. Also read off the pulse width modulation (PWM) signal from the accelerator pedal (AP) position sensor via the Electronic Throttle Module (ETM). Check that the difference between the signals is not more than approximately 10%. Check that the value is between 6-9% with an unaffected accelerator pedal (AP) and that the values increase as the accelerator pedal (AP) is pressed. The fault is intermittent if the signals are correct.

Continue Refer to «Checking components»(ref-408517-S25346041562011071200000)

ECM-959F is pretty much always stored as a result of another fault on the CAN network or as a subsequent diagnostic trouble code for an already detected fault on one of the signals from the accelerator pedal position sensor. Check whether any diagnostic trouble codes have been stored that indicate a fault on the CAN network, ECM-901A, ECM-902A, ECM-911A, ECM-912A, ECM-E003 and/or ECM-E000. If so, these diagnostic trouble codes must be fault traced first. If any diagnostic trouble code has been stored that indicates a fault in the accelerator pedal position sensor, ECM-9180, ECM-9520, ECM-9530, ECM-9540 and/or ECM-958F, these are to be fault traced first. Otherwise, continue as follows.

Using the diagnostic trouble code counter and parameters in VIDA vehicle communication, check whether the fault is intermittent or permanent. Compare the parameters "Accelerator pedal, PWM (via ETM)" and "Accelerator pedal, Analogue". These should under no circumstances differ by more than 10% unless the analogue signal is undergoing change, e.g. during throttle application, when a large deviation between the two signals is permitted.

If the diagnostic trouble code (DTC) is permanent

If diagnostic trouble code ECM-959F is stored as the only trouble code, it indicates that both the Engine Control Module (ECM) and Electronic Throttle Module (ETM) detect that the signals from the accelerator pedal position sensor are OK, even though the signal that the Electronic Throttle Module (ETM) sends back to the Engine Control Module (ECM) via the CAN network is faulty. This is a highly unlikely situation. Search for a fault that could cause the signal to be faulty yet still within the electrical fault limits.

Check the cables and connections between the Electronic Throttle Module (ETM) and the Engine Control Module (ECM) for contact resistance and corrosion.
Check whether there is any potential difference for ground connections and voltage supplies between the Engine Control Module (ECM) and the Electronic Throttle Module (ETM).

HINT: The signal cables between the accelerator pedal position sensor and the Engine Control Module (ECM) do not need to be checked. ECM-958F is generated if there is a fault on these cables.

If the diagnostic trouble code (DTC) is intermittent

For markets where upgraded software, released during year 2006 or later, is available, the solution may be to download the upgraded software. Since detection time has been increased from 0.5 to 0.9 seconds, the upgraded software will be much more tolerant to short, intermittent disruptions.

Remedy as necessary.

Other information

See «Identifying upgraded software ECM/ETM»(ref-438955-S16861622552011120700000)
See «Checking wiring and terminals»(ref-438953-S20310262912011120700000)

CAUTION

In order for Electronic Throttle Module (ETM) to reset any reconfigurations as well as delete internally stored problems, the following must be performed

Turn off the ignition and then wait three minutes for the main relay or system relay to release the voltage feed to, among others, Electronic Throttle Module (ETM).
Then turn on the ignition and turn it off again.
Wait another three minutes, but if the electric cooling fan is running you have to wait another two minutes after the cooling fan has stopped, to ensure that Electronic Throttle Module (ETM) is shut off correctly.

If this is not done correctly, diagnostic trouble codes may remain even after deletion of diagnostic trouble codes as well as any reconfiguration, despite the problem being fixed.

Continue Refer to «Information»(ref-408517-S41386845802011071200000)

In case of this defect, troubleshooting is not followed by verification.

The information can be displayed again or the fault-tracing for this fault can be interrupted.

Faulty signal. Intermittent fault

See Faulty signal. Intermittent fault

Faulty signal. Permanent fault

FAULT TRACING FAILED FAULT TRACING FAILED: 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.
VERIFICATION FAILED: 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. VERIFICATION FAILED: 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.
NEW TRY See «Faulty signal. Permanent fault»(ref-408517-S36389633042011071200000)
VERIFIED VERIFIED: Troubleshooting has been completed.

See Faulty signal. Permanent fault

This diagnostic trouble code is no longer necessary and has therefore been disabled in the software of later model years. In markets for which upgraded software (released 2006 or later) is available, the solution is to download the upgraded software since the diagnostic trouble code is disabled in this software.

See Identifying upgraded software ECM/ETM

For markets in which upgraded software is not available, check if the Engine Control Module (ECM) has stored other diagnostic trouble codes related to a fault that could have caused requested engine torque to be too high. If there are other diagnostic trouble codes that could have caused the fault, fault trace these. Remedy as necessary.

Remedy as necessary.

Other information

See «Identifying upgraded software ECM/ETM»(ref-438955-S16861622552011120700000)
See «Checking wiring and terminals»(ref-438953-S20310262912011120700000)

In order for Electronic Throttle Module (ETM) to reset any reconfigurations as well as delete internally stored problems, the following must be performed

Ignition off, wait three minutes so that the main relay / system relay releases the voltage feed to, among other, Electronic Throttle Module (ETM).
Then turn on the ignition and turn it off again.
Wait another three minutes, but if the electric cooling fan is running you have to wait another two minutes after the cooling fan has stopped, to ensure that Electronic Throttle Module (ETM) is shut off correctly.

If this is not done correctly, diagnostic trouble codes may remain even after deleting diagnostic trouble codes and any reconfiguration may remain, despite the problem being fixed.

Continue Refer to «Information»(ref-408517-S14796671912011071200000)

In case of this defect, troubleshooting is not followed by verification.

The information can be displayed again or the fault-tracing for this fault can be interrupted.

See Fault-tracing information

As described in the diagnostic trouble code information, this diagnostic trouble code is stored when the engine's current torque exceeds a maximal permitted torque for a short time. The diagnostic trouble code may be stored alone or exists as a subsequent problem of any another diagnostic trouble code.

If any of the diagnostic trouble codes ECM-1300, ECM-130A, ECM-260A, ECM-261A, ECM-262A, ECM-270A, ECM-271A, ECM-272A, ECM-6800, ECM-6805 and/or ECM-6806 are stored together with ECM-981A, continue troubleshooting according to any of these diagnostic trouble codes. Otherwise, continue as follows.

If there is no other diagnostic trouble code that indicates what may have caused exceeding of the engine's torque, then use the frozen values to try to determine when the problem occurred and what has caused the high torque. Also check the counters to get an idea if it is likely that the problem can be recreated or not. If the counters show that the problem has occurred frequently in recent time, it is highly likely that the problem can be recreated during troubleshooting. If the counters show that the problem is extremely intermittent, it is not very likely that the problem can be recreated during troubleshooting. A damage to following components or system would mean that the engine's torque becomes too high.

Check the intake system for air leakage and loose charge-air pipe.
Check that the wastegate valve does not jam, that the turbo control valve is not damaged or that there are cracked or blocked hoses between the turbo control valve and intake manifold or wastegate valve.

Remedy as necessary.

Other information

See «Checking wiring and terminals»(ref-438953-S20310262912011120700000)
See «Air leakage in the intake system, checking»(ref-408509-S38579558952011071200000)

CAUTION

In order for Electronic Throttle Module (ETM) to reset any reconfigurations as well as delete internally stored problems, the following must be performed: Ignition off, wait three minutes so that the main relay / system relay releases the voltage feed to, among other, Electronic Throttle Module (ETM). Then turn on the ignition and turn it off again. Wait another three minutes, but if the electric cooling fan is running you have to wait another two minutes after the cooling fan has stopped, to ensure that Electronic Throttle Module (ETM) is shut off correctly. If this is not done correctly, diagnostic trouble codes may remain even after deleting diagnostic trouble codes and any reconfiguration may remain, despite the problem being fixed.

Continue Refer to «Information»(ref-408517-S08725933622011071200000)

In case of this defect, troubleshooting is not followed by verification.

The information can be displayed again or the fault-tracing for this fault can be interrupted.

As described in the diagnostic trouble code information, this diagnostic trouble code is stored when the measured air mass in to the engine is below a lowest permitted air mass for a short time. The diagnostic trouble code may be stored alone, but the most common is that it exists as a subsequent problem of any another diagnostic trouble code.

If any of the diagnostic trouble codes ECM-1300, ECM-130A, ECM-901A, ECM-902A, ECM-903F, ECM-911A, ECM-912A, ECM-9150 and/or ECM-9160 are stored together with ECM-982A, continue troubleshooting according to any of these diagnostic trouble codes. Otherwise, continue as follows.

If there is no other diagnostic trouble code that indicates what may have caused the low air mass, then use the frozen values to try to determine when the problem occurred and what has caused the low air mass. Also check the counters to get an idea if it is likely that the problem can be recreated or not. If the counters show that the problem has occurred frequently in recent time, it is highly likely that the problem can be recreated during troubleshooting. If the counters show that the problem is extremely intermittent, it is not very likely that the problem can be recreated during troubleshooting.

A damage to following components or system would mean that the air mass becomes too low.

Check the intake system for air leakage and loose charge-air pipe.
Check that the intake air temperature (IAT) sensor and boost pressure sensor are correctly installed. Check for air leakage around the components. NOTE: Even extremely small air leaks can cause this diagnostic trouble code (DTC) to be stored.

For markets where upgraded software, released during year 2006 or later, is available, the solution may be to download the upgraded software. If the counters shows that the fault is intermittent and it is suspected that the fault occurs for a short time, the upgraded software will be of use as long as the faults do not occur for less than 0.6 seconds.

Remedy as necessary.

Other information

See «Identifying upgraded software ECM/ETM»(ref-438955-S16861622552011120700000)
See «Checking wiring and terminals»(ref-438953-S20310262912011120700000)
See «Air leakage in the intake system, checking»(ref-408509-S38579558952011071200000)

CAUTION

Continue Refer to «Information»(ref-408517-S13688809022011071200000)

In case of this defect, troubleshooting is not followed by verification.

The information can be displayed again or the fault-tracing for this fault can be interrupted.

A damage to following components or system would mean that the air mass becomes too low.

Check the intake system for air leakage and loose charge-air pipe.
Check that the intake air temperature (IAT) sensor and boost pressure sensor are correctly installed. Check for air leakage around the components. NOTE: Even extremely small air leaks can cause this diagnostic trouble code (DTC) to be stored.

Remedy as necessary.

Other information

See «Identifying upgraded software ECM/ETM»(ref-438955-S16861622552011120700000)
See «Checking wiring and terminals»(ref-438953-S20310262912011120700000)
See «Air leakage in the intake system, checking»(ref-408509-S38579558952011071200000)

CAUTION

In order for Electronic Throttle Module (ETM) to reset any reconfigurations as well as delete internally stored problems, the following must be performed

Ignition off, wait three minutes so that the main relay / system relay releases the voltage feed to, among other, Electronic Throttle Module (ETM).
Then turn on the ignition and turn it off again.
Wait another three minutes. If the electric cooling fan is running, you have to wait another two minutes after the electric cooling fan has stopped, to make sure that Electronic Throttle Module (ETM) has been shut off correctly. If this is not done correctly, diagnostic trouble codes may remain even after deleting diagnostic trouble codes and any reconfiguration may remain, despite the problem being fixed.

Continue Refer to «Information»(ref-408517-S00204000852011071200000)

In case of this defect, troubleshooting is not followed by verification.

The information can be displayed again or the fault-tracing for this fault can be interrupted.

See Level too low

See Fault-tracing information

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

The resistance between CAN-L and ground
The resistance between CAN-L and voltage
The resistance between CAN-H and ground
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?

YES Refer to «Identifying fault causes in the CAN network»(ref-408517-S41181197412011071200000)
NO Refer to «Checking the traffic load on the CAN cables»(ref-408517-S18946751682011071200000)

Scheme 1058

Connect the battery
Ignition on Also read: «Battery, disconnecting»(ref-438953-S33389199492011120700000) 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?

YES Refer to «Information»(ref-408517-S41930623292011071200000)
NO Refer to «Identifying a control module in the CAN network»(ref-408517-S33042964172011071200000)

Identifying fault causes in the CAN network

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 1 Mohms). 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.

Continue Refer to «Verification»(ref-408517-S10364398182011071200000)

Identifying a control module in the CAN network

Connect the battery Also read: «Battery, disconnecting»(ref-438953-S33389199492011120700000)
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.

Continue Refer to «Verification»(ref-408517-S10364398182011071200000)

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 ohms. 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.

Continue Refer to «Verification»(ref-408517-S10364398182011071200000)

Verification

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

Reinstall the connectors, components, etc.
Ignition on
Erase diagnostic trouble codes by clicking the VCT2000 symbol
Start the car. Allow the car to run for 10 minutes.
Read off diagnostic trouble codes (DTCs). Check if a diagnostic trouble codes (DTCs) for communication fault recurs in the central electronic module (CEM).

Does the diagnostic trouble code (DTC) recur?

YES Refer to «Information»(ref-408517-S42628125772011071200000)
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.

Supplementary information about faults in the CAN network

Information about "babbling control modules" and "disruptive control modules" in the CAN network

Definitions

Babbling control module: A control module that sends correctly formed messages on the CAN cables when it should actually be in sleep mode and as a result keeps the CAN network active. An obvious symptom is a discharged battery but no diagnostic trouble codes (DTCs) stored. A babbling control module will not produce interference on the CAN network while the car is being driven. A control module with incorrect software can occasionally produce symptoms similar to those from a babbling control module. This is detected using the fault-tracing method described below. The usual solution is to load new software
Disruptive control module: A control module that sends incorrectly formed messages on the CAN network, resulting in disruptions in the traffic between different control modules in the CAN network. This can result in the entire CAN network being shut down. Communication-related diagnostic trouble codes (DTCs) are normally stored.

Note. When taking readings on discharged batteries, remember that: The car can draw power from the battery for up to 20 minutes after the key has been removed from the ignition The Volvo ON Call Plus, Phone module (PHM), will draw power from the battery for approximately 1.5 minutes every 15 minutes to safeguard the remote unlocking function. This does not cause a major current drain from the battery.

When there are many CAN network-related faults, the fault is usually in the wiring. Diagnostic trouble codes (DTCs) E001 and E000 are usually stored as a result of a short-circuit between the green and white CAN wiring.

E003 and CEM-1A51-1A66 are usually stored as a result of an open-circuit. CEM-DFxx codes are usually stored as a result of a short-circuit to ground or supply voltage. Even if the above relate to the majority of the CAN-related faults, there have been cases where the control module itself has been the cause of the problems.

Each control module on the CAN network has an in-built CAN communication circuit. This is connected to the CAN network and is the component that regulates the voltage level at start up on the "high" CAN cable (CAN-H) and the "low" CAN cable (CAN-L) so that it is set to 2.5 V. When a control module starts transmitting on the CAN network, the voltage on CAN-H increases to approximately 3.5 V and the voltage on the CAN-L drops to 1.5 V. The traffic in the CAN network is redundant, which means that the messages can be interpreted by the receiving control module, even if the message comes on one of the two CAN cables.

A correctly communicating CAN-bus should have an average value of approximately 2.8 V between CAN H and ground, just below 2.3 V between CAN L and ground and approximately 0.5 V between both CAN-cables.

It is easiest to take the voltage readings using a multimeter. A VIDA oscilloscope can also be used to check the activity on the CAN network. However, it is not possible to see individual pulses or packages on the CAN network if the resolution of the oscilloscope is too low.

An internal fault in a control module can result in the control module not communicating correctly on the CAN network. This will be detected by the other control modules in the same section of the CAN network, which then start sending fault messages (known as "error frames").

In some special cases, the other control modules store diagnostic trouble code (DTC) E000 or E001 and then stop communicating on the CAN network. An example of this is where a control module intermittently short-circuits CAN H to 3.5 V and CAN L to 1.5 V. The other control modules will detect this and start sending "error frames", but do not necessarily store diagnostic trouble codes (DTCs). "Error frames" can be detected from dramatic increases in traffic on the CAN network as described in Case 2 below.

Case 1

"Babbling control modules" can discharge the battery because the CAN network is kept active. In individual cases, a "clicking sound" may be heard from the passenger door module (PDM) and the driver's door module (DDM) every 30 seconds after the key has been removed from the ignition switch.

This clicking sound is typical when there is a babbling control module somewhere in the low speed network, although it is not necessarily the case that anything will be heard. Babbling control modules are detected through increased activity on the CAN network and can be detected as follows

Measure the average voltage value between the white and green CAN cables. This value is normally approximately 0.5 V
Close all the doors, including the hood and the tailgate, remove the key from the ignition switch and wait for at least one minute. NOTE: Do not lock the doors.
Connect a voltmeter between the green and white CAN cables. NOTE: The VIDA cart cannot be connected when taking this reading. If VIDA is connected, the CAN network will never go into sleep mode as VIDA will ensure that there is still traffic. Use a free-standing measuring instrument instead and take the reading directly on the adapter wiring. The voltage between the green and white CAN cables must drop to 0 V. No activity (pulses) should be measurable on the network. If there is activity, cut the power to the control modules that are constantly powered (Steering wheel module (SWM), Upper electronic module (UEM), Rear electronic module (REM), Driver's door module (DDM), Passenger door module (PDM), "VOLVO On-call Plus" Phone module (PHM), Accessory electronic module (AEM) and Central electronic module (CEM)) one by one in that order until the voltage drops to 0 V and no activity can be seen on the CAN network. Use the relevant fuses for the control modules to cut their power. Do not disconnect them physically as this can affect other control modules on the CAN network
The control module to which the power was cut last when the CAN network voltage dropped to 0 V and the activity ceased is probably the faulty control module that is keeping the network active. If the passenger door module (PDM) or driver door module (DDM) is considered to be faulty, these can be disconnected physically from the CAN network as they are not connected in series in the CAN network. Note which control module causes the network voltage to drop to 0 V to determine which of the two is faulty. Do not replace both the driver's door module (DDM) and the passenger door module (PDM) as a pair. Fault-trace until the source of the fault has been found
Verify that the correct control module was faulty by repeating the fault, with and without the faulty control module connected in the CAN network. The above method cannot be used if the suspected control module is powered from the ignition switch, as these control modules would not discharge the battery.

Case 2

"Disruptive control modules". The advantage of these cases is that there are usually diagnostic trouble codes (DTCs) stored, for example E001 and CEM-1A51-1A64. The method described below can be used to distinguish between a wiring-related CAN fault, which is the most common, and a "disruptive control module". The most common customer complaint is that the indicators in the driver information module (DIM) drop to the 0-position.

See also: Information about the CAN network, structure and function

Both "babbling control modules" and "disruptive control modules" can have intermittent faults that are not necessarily apparent when the car is in the workshop. In some cases, "disruptive control modules" do not set diagnostic trouble codes (DTCs). The following method should therefore be used to fault-trace

Measure the voltage between the green and white CAN cables in the relevant CAN network. The average voltage value is normally 0.5 V
If a control module is "disruptive", the voltage is usually above 0.7 V
If this is the case, cut the power to the control modules in accordance with the method described about to find the fault cause
Verify that the correct control module was faulty by repeating the fault, with and without the faulty control module connected in the CAN network.

Note. Following faults with "babbling" or "disruptive" control modules, some control modules may remain in "Limp-home mode" even after the ignition key has been removed and inserted in the ignition switch again. To remedy this, disconnect and reconnect the battery negative terminal to restore the control modules to normal function.

Information about the CAN network, structure and function

This document explains how the structure of the CAN network, its function and how the on-board diagnostic system works. It also explains the circumstances under which diagnostic trouble codes (DTCs) are stored, as well as containing a few tips on how to conduct fault-tracing on the CAN network. Faults in the CAN network are often complicated to fault-trace because it is a distributed system and because diagnostic trouble codes (DTCs) are stored under different circumstances in different control modules.

The information in this document should ideally be used as a basis for understanding how the CAN network works, diagnostics for the system and how to carry out fault-tracing. There is no guarantee that it will help you find a fault source for a specific problem immediately. This document should be viewed as a supplement to the normal training information and is suitable for mechanics who have completed and understood the content of the "Volvo Automotive Networks" course.

Diagnostic functions in the central electronic module (CEM)

The central electronic module (CEM) is the only control module that monitors the voltage levels in the control area network (CAN). Only this control module can store diagnostic trouble codes (DTCs) for short-circuits between the CAN cables and ground or supply voltage (e.g. DTC CEM-DF14). However, other control modules can store diagnostic trouble codes (DTCs) for causes based on a short-circuit (e.g. DIM-E003). This is a small, but very important difference.

Note. The fact that the central electronic module (CEM) contains more diagnostics functions that other control modules does not mean that this control module is the cause of the fault. Do not replace the central electronic module (CEM) in the event of CAN-related faults unless an internal fault has been confirmed through fault-tracing in VIDA or using the information in this document.

The central electronic module (CEM) also has functions for determining whether other control modules have failed. All control modules on the CAN network must transmit and receive information. More specifically, all other control modules in the controller area network (CAN) must receive information from the central electronic module (CEM), and the central electronic module (CEM) must receive information from all other control modules in the controller area network (CAN). If a control module does not receive information from the central electronic module (CEM) it will store diagnostic trouble code (DTC) XXX-E003. If the central electronic module (CEM) cannot receive information from a control module it will store diagnostic trouble code (DTC) CEM-1A51 to CEM- 1A66 depending on which control module the central electronic module (CEM) is not receiving information from. For example, the climate control module (CCM) will store diagnostic trouble code (DTC) CCM-E003 if it does not receive information from the central electronic module (CEM), and the central electronic module (CEM) will store diagnostic trouble code (DTC) CEM-1A55 if it does not receive any information from the climate control module (CCM).

If there is an open-circuit in the CAN network, diagnostic trouble codes (DTCs) will be stored in pairs, one in the central electronic module (CEM) and one in the relevant control module. Note that this may result in the central electronic module (CEM) storing so many diagnostic trouble codes (DTCs) that it reaches its maximum (10).

These diagnostic trouble codes (DTCs) are explained in detail under Diagnostic trouble codes (DTCs) CEM-1A51 to CEM-1A66.

Diagnostic trouble codes (DTCs) for faults in the CAN network

Diagnostic trouble codes (DTCs) CEM-DF03 to CEM-DF16

The central electronic module (CEM) is the only control module that can detect a short-circuit to ground or to voltage. This is done by measuring the voltage level on the CAN cables via an internal voltmeter in the central electronic module (CEM) and as a result the diagnostic trouble codes (DTCs) CEM-DF03 to CEM-DF16 can be stored.

Note. There are different codes for the high speed and low speed networks. DF03, DF04, DF05 and DF06 refer to the low speed network while DF13, DF14, DF15 and DF16 refer to the high speed network.

There is no defined function for detecting an open-circuit in the CAN cables, but a number of diagnostic trouble codes (DTCs) will be stored as a result of an open-circuit. Diagnostic trouble codes (DTCs) CEM-DF03 to CEM-DF16 are the strongest indication of a fault in the CAN network, although the diagnostic trouble codes (DTCs) cannot localize the fault. Due to the criteria that cause these codes to be stored, diagnostic trouble codes (DTCs) can also be stored if the car is driven in areas with strong magnetic fields.

The CAN cables are monitored continuously for faults of this type. It can take up to ten seconds from the time the fault occurs until the diagnostic trouble code (DTC) is stored. Diagnostic trouble codes (DTCs) CEM-DF03 to CEM-DF16 are stored when the voltage on one of the CAN cables is higher than 4.5 V or lower than 0.5 V. A typical scenario when these codes are stored is when one of the CAN cables has been clamped together with a ground lead or a power supply cable.

Diagnostic trouble codes (DTCs) CEM-1A51 to CEM-1A66

The central electronic module (CEM) expects to receive a signal from each control module on the network. The control module stores a diagnostic trouble code (DTC) for faults in the communication with a control module, or "node not alive", if there is no communication for more than ten seconds.

The diagnostic trouble codes (DTCs) are normally stored in the event of an open-circuit in the CAN cables, a short-circuit to voltage or ground, when the control module has no supply voltage or if other circumstances cause the control module to stop communicating with the central electronic module (CEM). Combinations of diagnostic trouble codes (DTCs) CEM-1A51 to CEM-1A66 are very useful for localizing a fault in the network. See "Multiple diagnostic trouble codes (DTCs) and extended diagnostics" below.

If the status of diagnostic trouble codes (DTCs) CEM-1A51 to CEM-1A66 is intermittent, always check that communication is possible between all control modules when carrying out repairs. Then check the power supply and ground for the affected control modules. The control module will not store a diagnostic trouble code (DTC) if it was without power when the fault occurred. The central electronic module (CEM) on the other hand will store diagnostic trouble code (DTC) CEM-1A5X or CEM-1A6X even if the control module has no power supply or is experiencing other CAN communication problems.

Diagnostic trouble code (DTC) XXX-E003 stored in control modules other than the central electronic module (CEM)

Diagnostic trouble code (DTC) XXX-E003 is stored when an incorrect CAN configuration ID is received from a control module within 5 seconds of start up. This means that the control module cannot receive the data message with the correct Master Configuration ID that the central electronic module (CEM) transmits. This is normally due to an open-circuit on the CAN cables or some other interference in communication.

The diagnostic trouble code (DTC) is intended to detect whether the central electronic module (CEM) has defective software, but is more common when there are faults in the CAN network or faults in the power supply to the control modules. A combination of E003- codes makes it easier to localize the fault, see "Multiple diagnostic trouble codes (DTCs) and extended diagnostics" below. On the other hand, the diagnostic trouble code (DTC) is not stored at the same time in all control modules. This depends on the power supply to the control modules (e.g. X / 15 / 15I / 30).

The diagnostic trouble code (DTC) can be stored if incorrect software is downloaded into a control module or if a control module is moved from one car to another. This is why moving control modules between cars is not permitted. If several or all control modules have stored diagnostic trouble code (DTC) E003, this may be due to an incorrect signal configuration having been downloaded into the central electronic module (CEM). This is not particularly likely in practice, however, but is more often due to a physical fault in the CAN network.

X/ 15I / 15 supplied control modules can detect the fault five seconds after the control module has been powered up (ignition on). The control module compares its own CAN configuration ID (SW version) with the CAN configuration ID that is continuously transmitted by the central electronic module (CEM). Diagnostic trouble code (DTC) E003 is stored by the control module if the central electronic module (CEM) ID is absent or is different from the anticipated value five seconds after the control module has been powered up. An incorrect CAN configuration ID may be the result of a control module having been taken from one car and installed in another, although the diagnostic trouble code (DTC) is usually stored due to the signal being completely absent. A control module that is supplied directly from the battery (30) does not follow the same start up procedure as other control modules, but receives information about the position of the ignition key via the CAN network. This means that a 30-supplied control module will not store diagnostic trouble code (DTC) E003 5 seconds after the ignition is switched on if there is a permanent fault. The control modules will store the diagnostic trouble code (DTC) after a time-out lasting approximately ten minutes instead.

Note. This means that for a 30-supplied control module, the diagnostic trouble code (DTC) will be stored or not depending on when then fault occurred.

A typical reason for E003 being stored is an open-circuit in the CAN cables. In this case, the diagnostic trouble code (DTC) is often stored together the codes CEM-1A51 to CEM-1A66.

Diagnostic trouble codes (DTCs) E000 and E001 in a control module (E000=HS-CAN, E001=LS-CAN)

Diagnostic trouble code (DTC) E001 indicates a fault in the data communication on the CAN network. This can be due to interference of various types or if a control module is sending incorrect messages. Monitoring for this type of fault takes place continuously. The diagnostic trouble codes (DTCs) are originally intended to indicate contact bounces of if incorrect messages are sent over the network, but can also be stored in the event of a short-circuit between the two CAN cables or if communication only functions on one of the two cables. It takes a couple of seconds from the fault occurring to its detection.

Another important cause of these codes is if a control module has been disconnected from the network without the battery cable having been disconnected from the negative terminal (in such cases removing the ignition key does not help) or if the signal on the CAN cables is "weak" or disrupted. This can occur if communication is only working on one of the CAN cables or if one of the network resistors in the network is not working. The network resistors on the low speed network are located in the upper electronic module (UEM) and the rear electronic module (REM). On the high speed network, the resistors are located in the anti-lock brake system module (ABS)/brake control module (BCM) and in the electronic throttle module (ETM), except for Bosch EMS MY02 and later where the resistors are located in the brake control module (BCM) and the engine control module (ECM).

In certain cases, the diagnostic trouble code (DTC) may be stored if a control module sends data at the wrong transfer speed or if the crystal in a control module is defective.

Diagnostic trouble codes (DTCs) in the event of lost signal, rapid indication of faults on the CAN network

Some control modules, such as the engine control module (ECM), the electronic throttle module (ETM), the anti-lock brake system module (ABS) and the transmission control module (TCM) continually check the existence of each other and store diagnostic trouble codes (DTCs) in the event of missing signals. These diagnostic trouble codes (DTCs) are often due to different driving conditions and combinations of diagnostic trouble codes (DTCs) are often stored which can make fault-tracing more difficult. When attempting to recreate the fault, there is no guarantee that the same combination of diagnostic trouble codes (DTCs) will be stored. The detection of these diagnostic trouble codes (DTCs) is often more sensitive and they are usually stored more easily than CEM-1A51 to CEM-1A66 or CEM-DF03 to CEM-DF16. This can therefore be an indication of a short-term intermittent fault having occurred on the CAN network.

Below is a selection of diagnostic trouble codes (DTCs) that may or may not be stored in the event of an intermittent fault on the CAN network

ECM-928C (Bosch), ECM-922A (Denso), only when the engine is running. These diagnostic trouble codes (DTCs) indicate that the control signal for the cruise control is missing or could not be received by the engine control module (ECM)
ECM-901A, ECM-901E, ECM-902A, ECM-911A, ECM-912A and ECM-913A for Bosch and ECM-901A, ECM-902A, ECM-911A, ECM-912A for Denso
SRS-00D6, time-out for the seat belt buckle. This diagnostic trouble code (DTC) indicates that the supplemental restraints system module (SRS) has not received the status of the seat belt buckles from the central electronic module (CEM). The sensor for the seat belt buckles is directly linked to the central electronic module (CEM)
SRS-00D5, status of the SRS indicator lamp in the driver information module (DIM)
Discrepancies in the signal from the pedal position sensor between the directly connected signal and the signal over the CAN network. See the table below.

Engine control module (ECM) Bosch
	ECM-959F	Fault when comparing the signals AP12T APU (Analog Pedal Unit) Analog and PWM (from the electronic throttle module (ETM))
Engine control module (ECM) Denso
	ECM-9520	ETS, APM, PWM, electrical fault, signal too low
Monitoring the engine control module (ECM)
Bosch
	ECM-510F	No speed signal
Denso	ECM-510D	No speed signal
	ECM-A02B	No signal from the anti-lock brake system module (ABS)/brake control module (BCM)
	ECM-902A	Communication fault with the electronic throttle module (ETM)

Multiple diagnostic trouble codes (DTCs) and extended diagnostics (counters and freeze frames)

The detection time for faults in the CAN network varies depending on the diagnostic trouble code (DTC). This means that for different fault occurrences, different diagnostic trouble codes (DTCs) can be stored in different control modules. Several diagnostic trouble codes (DTCs) in different control modules can be confusing and must be investigated at the start of fault-tracing to check for any link between the various codes.

It is now possible to read off extended diagnostic trouble code (DTC) information in VIDA, normally counters and frozen values. This can also help with fault-tracing on the CAN network as it can provide information about diagnostic trouble codes (DTCs) that are stored simultaneously. Remember that the function using counters can be implemented differently in different control modules, which can make it difficult to compare cycles between different control modules.

When performing fault-tracing on a car with many intermittent E003 and CEM-1A51 to CEM-1A66 diagnostic trouble codes (DTCs), this can be made easier by checking the affected control modules. Cop the diagram in the appropriate service information for the relevant car model, and write down all diagnostic trouble codes (DTCs) and counters at the relevant control modules. Check any conclusions can be drawn from where the diagnostic trouble codes (DTCs) are stored. If the diagnostic trouble codes (DTCs) are in control modules at one end of the CAN network, this can give an indication of where the fault may be located.

Limp-home modes and characteristics of control modules in the event of faults in the CAN network

When a control module cannot receive messages from the central electronic module (CEM) it will go into Limp-home mode. In such cases, the control module can retain part of its functionality. The remaining functionality varies in different control modules. If a fault occurs after a control module has been started up, it will normally retain the most recent values as the Limp-home values. There are exceptions, such as the fuel gauge in the driver information module (DIM).

Some clear examples for the low speed side network

Driver information module (DIM): As the driver information module (DIM) only displays signals received from the CAN network, it will soon be evident if signals are lost. The display of various signals will disappear at slightly different times due to some filtering of the signals in the driver information module (DIM). The values on the gauges are normally frozen for around ten seconds before dropping to zero and the driver information module (DIM) shuts down. If only one control module has disappeared from the network, the driver information module (DIM) can display the first indication of this. An example of this is where the rear electronic module (REM) stops communicating, which is indicated by the fuel gauge dropping to zero
Climate control module (CCM): This control module must retain some of its functionality even if the CAN communication is lost. It is also a very good indication of whether the CAN communication has been lost, as the LEDs will light up exactly ten seconds after the ignition key has been turned to positions one or two. Other symptoms: if the AC compressor is not working, apart from the first second when the function is checked by the engine control module (ECM), this can indicate a fault in the climate control module (CCM)>central electronic module (CEM)>engine control module (ECM) chain. Another very obvious symptom is that the blower fan continues to operate for up to ten minutes after the key is removed from the ignition switch. This is because the climate control module (CCM) is powered via Extended-X from the central electronic module (CEM). The climate control module (CCM) normally switches off the blower fan and other functions when it does not receive a signal over the CAN network after the ignition key has been removed. If there is no CAN communication, the climate control module (CCM) will continue to operate until the central electronic module (CEM) switches off the power supply
Driver door module (DDM)/Passenger door module (PDM): The module will be set to a resting mode and no functions will be performed, such as setting the mirror or operating the power windows
Power seat module (PSM): The memory function in the seat will not work. Stored positions for seats and mirrors will not work when the car is unlocked with a remote control
Upper electronic module (UEM): The seat belt reminder will be lit, even though the belt is secured in the seat belt buckle. It will not be possible to lock or unlock the car using the remote control
Audio module (AUM): The radio retains most of its functionality. However, the buttons on the steering wheel will not work
Rear electronic module (REM): The fuel gauge is not working and it will not be possible to lock/unlock the rear doors using the central locking switch. The heating loops in the rear windshield and the rear folding head restraints will not work
Steering wheel angle sensor module (SAS): The anti-skid system will not work
Steering wheel module (SWM): Buttons on the steering wheel and the turn signal lamp stalk will not work. However the horn will still work because it is connected directly to the central electronic module (CEM).

Some clear examples for the high speed network

Engines: Cannot be started as a result of no communication between the central electronic module (CEM) and transmission control module (TCM) + engine control module (ECM) Level 1: No cruise control function Level 2: Accelerator pedal "heavy". Poor response Level 3: Present Limp-home mode. The engine speed (RPM) is controlled via the injectors.
Electronic throttle module (ETM): The node has three Limp-home levels: Level 1: No cruise control function Level 2: Accelerator pedal "heavy". Poor response Level 3: Present Limp-home mode. The engine speed (RPM) is controlled via the injectors.
Transmission control module (TCM): It is not possible to use all the gears. NOTE: If the control module has gone into Limp-home due to an open-circuit in the CAN communication, the functionality will not return during the cycle, even in the event of the fault disappearing.
Anti-lock brake system module(ABS)/Brake control module (BCM): The remaining functionality depends on what fault has occurred. In the event of a fault in the AYC sensor, the indicator lamp lights and DSTC stops working. Faults in the wheel sensors cause the indicator lamp to light and the ABS function to disappear, although there is still braking assistance. The unit can lose certain diagnostics in Limp-home mode
Central electronic module (CEM): Extremely large loss of function. It is worth noting that the control module has separate circuits for the high speed and low speed networks. This means that it is possible to communicate with the control module via the high speed network even when the low speed network has a fault.

Fault-tracing tips

If the central electronic module (CEM) has stored diagnostic trouble code (DTC) CEM-DF14 CAN low short-circuit to ground, this does not mean that the central electronic module (CEM) is necessarily the control module which short-circuits the cable. The short-circuit may be from any part of the cable to any ground terminal or ground lead. The fault may be in a cable harness, which is the most common situation, or in a control module. Note that the diagnostic trouble code (DTC) can be stored in some control modules but not in others, and that the short-circuit in this case can be far from the control module that stores the diagnostic trouble code (DTC).

Statistically there is a high likelihood of the fault being in the cable harness (check behind the audio module (AUM), at the supplemental restraint system module (SRS), the terminals for the CAN cables in the connectors on the transmission control module (TCM) and the engine control module (ECM). Note that terminal pins (P/N 9441394) can be used to check the mating surface in the female connectors for the CAN cables. If the mating surface is defective or the terminal pins detach too easily, the female connector socket must be replaced (P/N 9442486).

If diagnostic trouble code (DTC) E001 is stored continually and the cable harness is free of faults, all control modules containing diagnostic trouble code (DTC) E001, apart from the central electronic module (CEM), must be disconnected from the CAN network. Delete the diagnostic trouble codes (DTCs) in the remaining control modules and read off diagnostic trouble codes (DTCs) again to see if the fault disappears. Then connect the control modules again, one by one, until the diagnostic trouble code (DTC) recurs. If VIDA can communicate with the car when the ignition key is in position 0 and 1 but not in position 2, the fault is probably in a 15-supplied control module.

The above method can also be used in other scenarios. On rare occasions, control modules can begin sending irrelevant messages on the CAN network. This can prevent the correct messages from getting through. The result can be one or more E003 or CEM-1A51 to 1A66 diagnostic trouble codes (DTCs). It may be difficult to determine which control module is causing the interference. In this case, the above method may be the only way of finding the fault source.

If none of the control modules on the LS-CAN respond but a response is received from the control modules on HS-CAN

The central electronic module (CEM) protects the CAN network from short-circuits caused by the data connection device. This is achieved with the aid of four internal relays, one for each CAN cable. The relays are closed when the central electronic module (CEM) receives a signal from VIDA on the communication cable.

If the above problem occurs, check the following

The VCT2000 cable. This cable has given problems before. Try with a different cable and a different VCT2000
Continuity and signal level on the communication cable
Continuity and signal level in the CAN cables between the connector and the central electrical module (CEM).

If points one to three do not produce a result, the fault is probably a permanent cable fault in the CAN network or in a control module. Continue fault-tracing according to "CAN network hardware and measurement methods" below.

CAN network hardware and measurement methods

The CAN network is connected using resistors (120 ohms each) between the two CAN cables (green (GN) for CAN-L, white (W) for CAN-H) in some control modules. The two control modules in the low speed network (in principle the passenger compartment) that have resistors are the rear electronic module (REM) and the upper electronic module (UEM). In the high speed network (in principle the engine compartment), the position of resistors depends on the engine type and model year. For model years 99-01, the resistors are positioned in the anti-lock brake system module/brake control module (ABS/BCM) and the electronic throttle module (ETM). In cars from model year 02 with Bosch EMS, the electronic throttle module (ETM) is no longer part of the CAN network. The resistor in this case is located in the engine control module (ECM).

Measurement method

To localize a permanent fault in the CAN network, the resistance can be measured in the network. When taking resistance readings, the battery negative terminal must be disconnected and the resistance must be close to 60 ohms. An open-circuit in one or both CAN cables will produce a resistance of 120 ohms. The recommended approach is to measure the resistance using a breakout box connected to the central electronic module (CEM). This has the following advantages

The reading is taken with the central electronic module (CEM) connected. Note that open-circuits in the anti-lock brake system module/brake control module (ABS/BCM), steering wheel angle sensor module (SAS), power seat module (PSM), passenger door module (PDM), driver's door module (DDM) audio module (AUM) will not affect the reading as these control modules are not connected in series. The reading only checks the "main artery in the CAN network". However, a short-circuit between the two cables will be detected
There is easy access to the low speed network, the high speed network and the cables between the central electronic module (CEM) and the connector
If a multimeter is connected, this can be positioned in front of the driver's seat and the cable harness/connectors can be twisted above the central electronic module (CEM). It is then easy to see any changes in resistance
As in point 3, twist and turn the cables/junction behind the radio where the cables lie against the rear wall of the engine compartment
As in point 3, move the cables/junction connected to the cable harness in the headlining by the A-post
As in point 3, ask someone to twist and turn the cables under the cooling box for the central electronic module (CEM) and the transmission control module (TCM).

If for some reason it is not possible to use the breakout box for the central electronic module (CEM), the low speed network can be measured using the breakout box for the power seat module (PSM) or in its connector when the power seat module (PSM) is disconnected.

These measurements are particularly effective when diagnostic trouble codes (DTCs) CEM-1A51 to 1A66 and E003 or E001 are stored without diagnostic trouble codes (DTCs) CEM-DF03 to DF16 being stored. When taking resistance readings, also check that none of the cables are short-circuited to ground or voltage, which ought to have stored CEM-DF03 to DF16. The resistance should be several kohms.

For intermittent faults, the oscilloscope is very useful. The reading should be taken with all control modules connected and powered up using the breakout box. Check that the voltage on CAN-H never exceeds 4.5 V and that CAN-L is never below than 0.5 V. Note that the oscilloscope in VIDA is not sufficiently accurate (measurement speed too low) for detailed measurement of the traffic on the CAN network, but can give an indication of the voltage levels that exist and whether communication exists or not.

Note. Never take readings directly in the connector using the test probes of the multimeter. This can result in damage to the connector and entail insufficient contact when the connector is reassembled. Use a terminal pin instead.

General

Increasing demands for further functionality in the vehicle, both statutory requirements and customers, have led to increased complexity in the vehicle.

This, in turn, has encouraged developments towards more flexible electrical systems. The CAN-net (Controller Area Network) is a result of this research. The network permits the transmission and receipt of a large number of different commands and messages on the same wiring. Earlier, every command or message required a separate cable. Using networks has allowed functionality to be expanded without increasing the number of cables.

The number of commands and messages which can be handled on the network depends on factors such as the network speed and the length of the message or command. The Volvo network which is based on a control area network (CAN), can transmit over 500 different signals and approximately 100 messages. These messages are also called frames. Each message can contain several signals, e.g., a message to Rear electronic module (REM) can contain all signals for how the tail lights should be lit.

Advantages of a network

Easier to add further functions and install accessories.

Because the control modules in the network are already connected to each other and are easy to add more information to, all that is required is

to connect the sensors to the nearest control module
to connect the controlled component to the nearest control module
to download software to alter the configuration and programming of the network.

The length of the wiring and the number of components which are introduced with the vehicle are less than previously.

An example of this is the addition of cruise control for the car.

Before the introduction of the network the installation of control modules, switches, vacuum pumps, vacuum servos, hoses and cable harnesses was necessary.

With the network only the installation of a switch and the downloading of software which alters the configuration of the vehicle is required.

Easier to introduce logical functions.

Logical functions can be explained as "If this occurs then the following corrective action must be carried out". For example, the system is programmed so that if a tail light is broken, a message is transmitted via the control area network (CAN) to the driver information module (DIM) to warn the driver.

The only thing you need to do to introduce a logical function is alter the programming of control modules affected - the rear electronic module (REM) and the driver information module (DIM) in the example above.

Introduction of logic functions does not increase the number of components or cables.

Easy to adapt the system to customer and market requirements.

The functions can be altered depending on the requirements/demands of the customer and market. An example of this could be fog tail lamps. Certain markets use two fog tail lamps, others only use one on the driver's side. Previously it was required that different replacement parts were stored for different markets. Now the same replacement part can be used for all markets, by changing the programming depending on the market.

A similar basic system can be used for a whole model program.

Similar networks (hardware) can be used for a large number of different vehicles.

The only thing that differentiates the vehicles is

the components (control modules, sensors controlled components etc.) which are connected to the system
Which components do what.
Which components/functions are standard /optional/accessories
Configuration/programming of the system

Faulty communication

See Faulty communication

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).

Signal faulty. Intermittent fault

See Signal faulty. Intermittent fault

Replacing and programming the Engine Control Module (ECM)

The Engine Control Module (ECM) has registered an incorrect configuration.

CAUTION

A new Engine Control Module (ECM) is delivered without software. The Engine Control Module (ECM) must be programmed before it will function after replacement.

For information about programming and replacing the Engine Control Module (ECM), see Engine Control Module (ECM), replacing .

Continue Refer to «Information»(ref-408517-S37256057672011071200000)

In case of this defect, troubleshooting is not followed by verification.

The information can be displayed again or the fault-tracing for this fault can be interrupted.

See Faulty signal. Permanent fault

Checking canister purge (CP) valve

Check canister purge (CP) valve for dirt, deposits and damage.

Activate the canister purge (CP) valve to see that no malfunction has occurred.

Check that the canister purge (CP) valve is not sticking when it has been activated.

Continue Refer to «Information»(ref-408517-S29677981122011071200000)

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).

Check canister purge (CP) valve for dirt, deposits and damage.

Activate the canister purge (CP) valve to see that no malfunction has occurred.

Check that the canister purge (CP) valve is not sticking when it has been activated.

Continue Refer to «Information»(ref-408517-S40027780362011071200000)

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).

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

Start the engine.
Activate the quick fuel tank system test.

Is the value OK?

YES VERIFIED: Troubleshooting has been completed.
NO Refer to «Information»(ref-408517-S22755706902011071200000)

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.

Engine Performance Diagnostic Trouble Code (DTC) Diagnostics - 7 of 7 (Coupe): Other Volvo C70 I

Checking components

Scheme 1049

Fault-tracing information

Signal too high. Intermittent fault

Scheme 1050

Scheme 1051

Scheme 1052

Faulty signal

Scheme 1053

Scheme 1054

Signal too high/signal too low

Level too low

Checking the status

Scheme 1055

Scheme 1056

Scheme 1057

Faulty signal. Intermittent fault

Faulty signal. Permanent fault

Checking a short-circuit in CAN cables

Scheme 1058

Identifying fault causes in the CAN network

Identifying a control module in the CAN network

Verification

Supplementary information about faults in the CAN network

Information about the CAN network, structure and function

General

Advantages of a network

Faulty communication

Signal faulty. Intermittent fault

Replacing and programming the Engine Control Module (ECM)

Checking canister purge (CP) valve

More articles — Engine Performance Diagnostic Trouble Code (DTC) Diagnostics - 7 of 7 (Coupe)

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