Faulty Signal 12
Faulty signal 12
Frozen values and counter for diagnostic trouble codes.
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. Driving conditions may be, e.g., if the engine was running, what speed the vehicle had, or how long the driving distance was.
Counter
The counters are used to determine the problem's status. For general information about the counters, see: Counters, description Description of Counter
Counter 1 indicates the number of drive cycles without fault since the fault was last validated.
If counter 1 is the same as 0, this means that the fault has been detected in this operating cycle (permanent fault). If no troubleshooting or repair has been performed in the vehicle in this driving cycle, the problem is probably in the vehicle.
If counter 1 is over 0, this indicates that the problem has not been detected in this driving cycle (intermittent problem). The problem has existed earlier but is not active right now.
Then check counter 4. Counter 4indicates number of driving cycles with problem since the problem was validated for the first time.
If the number of driving cycles with problems is high, this indicates an intermittent recurring problem, which means greater possibility of regenerating the problem in the workshop.
If the number of driving cycles with problems is low, this indicates an intermittent temporary problem, which means small possibility of regenerating the problem.
Hint: Counter 3 indicates number of driving cycles since first time that the problem occurred. If the value for counter 3 is divided by the value for counter 4, the intensity of the problem is obtained. The higher the value, the higher the problem intensity. A high problem intensity indicates that the malfunction recurs often.
Counter 5 can be used for more exact determination of when the problem occurred. To compare counter 5 for diagnostic trouble codes indicates in which order the diagnostic trouble codes were stored.
5-cyl. non-turbo engines
For model year 1999, only counter 1 and 2 are available.
Frozen values
The frozen values show the driving conditions when the control module detected the problem the first time. Check using the frozen values that the diagnostic trouble code has not been caused accidentally during troubleshooting of the vehicle. If the driving distance is 0 km/miles, this indicates that the problem has occurred at the control modules' start-up of the CAN-net, when reception of a relevant value has not been possible. This also applies to other values that come via the CAN-network. In these cases, counter 5 can be used to determine when the problem was generated.
If the diagnostic trouble code has been caused during this troubleshooting, it may be due to, e.g., disconnected component, too low or high battery voltage, or that some control module has been disconnected.
If the diagnostic trouble code has been stored since before, there has likely been a problem or interference, which has resulted in the control module detecting a problem.
For general information about frozen value, see: Information Information
For information about frozen values.
- Turbo engines and 6-cyl. non-turbo engines: Description of frozen values Me7 Description of Frozen Values Me7
- 5-cyl. non-turbo engines: Frozen values DENSO, description Frozen Values DENSO, Description
Read off the diagnostic trouble code's counter and frozen values by clicking on the symbol for VCT2000. Choose diagnostic trouble code in question.
Continue - DONE
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DONE - Fault-tracing information
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Fault-tracing information
Fault-tracing information
Checking software
The fault tracing that follows depends on whether the software in the control module is upgraded. The control module's software version can be read out using VIDA vehicle communication.
Note! This fault tracing applies for:
- Model year 1999, diagnostic trouble code ECM-900E, Faulty signal 12.
- Model year 2000-2002, diagnostic trouble code ECM-980F.
From model year 2000, diagnostic trouble code ECM-900E, Faulty signal 12, has been renamed ECM-980F.
Is the software upgraded?
Yes - Upgraded software.
No - Software not upgraded.
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Upgraded software.
As described in the diagnostic trouble code information, this code is designed to monitor whether airflow to the engine is within permitted limits. The diagnostic trouble code is pretty much always stored as the result of another trouble code in the engine control module (ECM). Check whether the engine control module (ECM) has stored any other diagnostic trouble codes that indicate a problem with airflow into the engine.
If any other diagnostic trouble code has been stored that indicates a problem with the air flow sensor and/or the induction pipe pressure sensor, this indicates that there may have been a problem with the airflow. Any diagnostic trouble codes that are stored should be fault traced first. If ECM-1300, ECM-130A, ECM-1400, ECM-140A and/or ECM-150A are stored, fault trace these diagnostic trouble codes.
If other diagnostic trouble codes have been stored that indicate a communication fault on the CAN network, it indicates that trouble code ECM-980F/ECM-900E, Faulty signal 12, may have been stored because the engine control module (ECM) did not have correct information on throttle position when permitted air flow was calculated. If ECM-901A, ECM-902A, ECM-902B, ECM-911A, ECM-912A and/or ECM-E000 are stored, fault trace these diagnostic trouble codes.
If other diagnostic trouble codes have been stored that indicate a problem with the throttle unit or its throttle control, this indicates that there may have been a problem with the airflow. Any diagnostic trouble codes that are stored should be fault traced first. If ECM-903F, ECM-914F, ECM-9150, ECM-9160, ECM-9190 and/or ECM-91A7 are stored, fault trace these diagnostic trouble codes.
If ECM-980F/ECM-900E, Faulty signal 12, is stored alone without any of the above diagnostic trouble codes, use the trouble code's frozen values plus the counter to determine the operating conditions when the fault was first detected and how often the fault occurred. The values show the problem's current status and how intermittent the problem is. If the diagnostic trouble code (DTC) was stored under operating conditions that means external factors, such as low battery voltage during engine start-up, are suspected to be the cause fault-trace and remedy as necessary.
- Check whether there are any other indications that there could have been incorrect airflow.
- Check for air leaks between the throttle unit and the cylinder head.
For markets where upgraded software, released during year 2006 or later, is available, the solution may be to download the upgraded software. This is because the upgraded software requires that the air mass measured by the mass air flow sensor must be sufficiently greater than the calculated air mass for the diagnostic trouble code to be generated.
Other information
- Check for air leaks in the intake system Air Leaks in the Intake System, Checking
- Checking wiring and terminals Checking Wiring And Terminals
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 - Information
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Software not upgraded.
As described in the diagnostic trouble code information, this code is designed to monitor whether airflow to the engine is within permitted limits. The diagnostic trouble code is pretty much always stored as the result of another trouble code in the engine control module (ECM). Check whether the engine control module (ECM) has stored any other diagnostic trouble codes that indicate a problem with airflow into the engine.
If any other diagnostic trouble code has been stored that indicates a problem with the air flow sensor and/or the induction pipe pressure sensor, this indicates that there may have been a problem with the airflow. Any diagnostic trouble codes that are stored should be fault traced first. If ECM-1300, ECM-130A, ECM-1400, ECM-140A and/or ECM-150A are stored, fault trace these diagnostic trouble codes.
If other diagnostic trouble codes have been stored that indicate a communication fault on the CAN network, it indicates that trouble code ECM-980F/ECM-900E, Faulty signal 12, may have been stored because the engine control module (ECM) did not have correct information on throttle position when permitted air flow was calculated. If ECM-901A, ECM-902A, ECM-911A, ECM-912A and/or ECM-E000 are stored, fault trace these diagnostic trouble codes.
If other diagnostic trouble codes have been stored that indicate a problem with the throttle unit or its throttle control, this indicates that there may have been a problem with the airflow. Any diagnostic trouble codes that are stored should be fault traced first. If ECM-903F, ECM-914F, ECM-9150, ECM-9160, ECM-9190 and/or ECM-91A7 are stored, fault trace these diagnostic trouble codes.
Model year 2001-2002.
If ECM-980F is stored together with ECM-9818, but none of the above diagnostic trouble codes are stored, use the trouble code's frozen values and the counter to determine the operating conditions when the fault was first detected and how often the fault occurred. The values show the problem's current status and how intermittent the problem is.
If the frozen values indicate that both diagnostic trouble codes were stored at about the same time, just after the engine started, when the air mass into the engine seems OK but the pressure in the induction pipe is the same as the air pressure around the vehicle, this is a fault detection and not a problem with airflow.
For markets where upgraded software, released during year 2006 or later, is available, the solution may be to download the upgraded software. This is because the upgraded software requires that the air mass measured by the mass air flow sensor must be sufficiently greater than the calculated air mass for the diagnostic trouble code to be generated. This makes it more tolerant to disturbances such as this one.
For markets in which upgraded softare is not available, check if there is any reason why the pressure sensor did not indicate that pressure in the induction pipe was much lower than air pressure when the diagnostic trouble code was generated.
- Check vacuum hoses and connections between the pressure sensor and induction pipe for clogs, condensation and dirt.
If ECM-980F/ECM-900E, Faulty signal 12, is stored alone without any of the above diagnostic trouble codes, use the trouble code's frozen values plus the counter to determine the operating conditions when the fault was first detected and how often the fault occurred. The values show the problem's current status and how intermittent the problem is.
- Check whether there are any other indications that there could have been incorrect airflow.
- Check for air leaks between the throttle unit and the cylinder head.
For markets where upgraded software, released during year 2006 or later, is available, the solution may be to download the upgraded software. This is because the upgraded software requires that the air mass measured by the mass air flow sensor must be sufficiently greater than the calculated air mass for the diagnostic trouble code to be generated.
Model year 1999-2000:
If ECM-980F/900E, Faulty signal 12, is stored alone, but none of the above diagnostic trouble codes are stored, use the trouble code's frozen values and the counter to determine the operating conditions when the fault was first detected and how often the fault occurred. The values show the problem's current status and how intermittent the problem is.
If the frozen values indicate that both diagnostic trouble codes were stored at about the same time, just after the engine started, when the air mass into the engine seems OK but the pressure in the induction pipe is the same as the air pressure around the vehicle, this is a fault detection and not a problem with airflow.
For markets where upgraded software, released during year 2006 or later, is available, the solution may be to download the upgraded software. This is because the upgraded software requires that the air mass measured by the mass air flow sensor must be sufficiently greater than the calculated air mass for the diagnostic trouble code to be generated. This makes it more tolerant to disturbances such as this one.
For markets in which upgraded softare is not available, check if there is any reason why the pressure sensor did not indicate that pressure in the induction pipe was much lower than air pressure when the diagnostic trouble code was generated.
- Check vacuum hoses and connections between the pressure sensor and induction pipe for clogs, condensation and dirt.
If the frozen values indicate that ECM-980F/ECM-900E, Faulty signal 12, was not stored directly after engine start, use the diagnostic trouble code's frozen values and the counter to determine the operating conditions when the fault was first detected and how often the fault has occurred. The values show the problem's current status and how intermittent the problem is.
- Check whether there are any other indications that there could have been incorrect airflow.
- Check for air leaks between the throttle unit and the cylinder head.
For markets where upgraded software, released during year 2006 or later, is available, the solution may be to download the upgraded software. This is because the upgraded software requires that the air mass measured by the mass air flow sensor must be sufficiently greater than the calculated air mass for the diagnostic trouble code to be generated. This makes it more tolerant to disturbances such as this one.
Other information
- Check for air leaks in the intake system Air Leaks in the Intake System, Checking
- Checking wiring and terminals Checking Wiring And Terminals
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 - Information
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Information
Fault-Tracing Information
Fault-tracing is not followed by verification for this fault.
The information can be displayed again or fault-tracing this fault can be interrupted.
Do you want to view the information again?
YES: Repeat Procedure.
NO: Troubleshooting complete for this DTC.
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