Fuel, Ignition & Engine Control Systems - Removal & Installation, Description (Convertible): Diagnosis Volvo C70 I

Information about combined diagnostic trouble codes (DTCs) (Non-Turbo)

Combined diagnostic trouble codes (DTCs)

The following table is available to facilitate fault-tracing of ETM related diagnostic trouble codes (DTCs).

Note. Probable root diagnostic trouble codes (DTCs) are in bold and listed at the top of each cell.

Example of how to read table: If the codes 902A 903F 912A 980F are set, then 902A is the likely root trouble code.

The diagnostic trouble codes (DTCs) can also be stored individually or together with other diagnostic trouble codes (DTCs) that do not affect ETM.

Note. There are two different tables, one for cars with upgraded software released during 2006 or later, and one for cars that are not upgraded with this software. See Identifying upgraded software ECM/ETM

5-cyl non-turbo engines, for upgraded software released during 2006 or later

5-cyl non-turbo engines, for non-upgraded software

Information about combined diagnostic trouble codes (DTCs) (Non-Turbo and Turbo)

Combined diagnostic trouble codes (DTCs)

The following table is available to facilitate fault-tracing of ETM related diagnostic trouble codes (DTCs).

Note. Probable root diagnostic trouble codes (DTCs) are in bold and listed at the top of each cell.

Example of how to read table: If the codes 1300 and 904C are set, then 1300 is the likely root trouble code.

The diagnostic trouble codes (DTCs) can also be stored individually or together with other diagnostic trouble codes (DTCs) that do not affect ETM.

Note. There are two different tables, one for cars with upgraded software released during 2006 or later, and one for cars that are not upgraded with this software. See Identifying upgraded software ECM/ETM

5/6-cyl turbo and 6-cyl non-turbo engines, for upgraded software released during 2006 or later

5/6-cyl turbo and 6-cyl non-turbo engines, for non-upgraded software

Leak diagnostic pump, replacing

1. For C70, see «Leak diagnostic pump, replacing»(ref-403955-S00451849702011061000000) .

Scheme 300

All gases that evaporate from fuel in the fuel tank must be led to and stored in the evaporative emission system (EVAP) canister so that they can be directed into the engine for combustion. In order to detect leakages which cause evaporation of gases into the air, the fuel tank system is diagnosed for leakage. The fuel tank system consists of

1. fuel tank
2. the EVAP canister purge valve (1)
3. EVAP canister (2)
4. leak diagnostic unit (3)
5. air cleaner (ACL) (4)
6. Roll-over valve (5)
7. Float Limit Vent Valve (6)
8. fuel filler pipe (7)
9. all lines between the above components.

The fuel tank system has a leak diagnostic unit to diagnose any leakage. The leak diagnostic unit pressurizes the fuel tank system when the conditions for leak diagnostics are met.

The control module can detect faults in the function of the leak diagnostic unit and leakage that is 0.5 mm or greater. Minor leak; leakage greater than 0.5 mm but less than 1.0 mm. Major leak; leakage greater than 1.0 mm.

The leak diagnostic unit consists of a pump and a valve that controls the air flow in the unit. The Engine control module (ECM) checks for leakage in the fuel tank system by measuring the relationship between reached pressure and flow from the leak diagnostic pump during pressurization.

If a certain pressure is not reached with a predetermined supplied flow (with known mass), the Engine control module (ECM) interprets this as a leak from the fuel tank system.

Leak diagnostics starts in normal operation when specific conditions are met, see below. The diagnostics can also be started on command using VIDA when some of these conditions are ignored.

Conditions for diagnosis

The diagnosis begins when all the following conditions are met.

Note: When diagnostics are started on command using VIDA, certain different conditions apply. See relevant information about these, available with starting Quick test fuel tank system.

1. No diagnostic trouble codes (DTCs) for EVAP valve or atmospheric pressure sensor may be stored.
2. The engine is switched off until the engine coolant temperature (ECT) has fallen to a few degrees above the outside temperature, then engine running for at least 10 minutes
3. Ignition off
4. Vehicle speed 0 km/h.
5. Engine coolant temperature (ECT) 4-35°C.
6. Maximum altitude of 2500 meters above sea level
7. Outside temperature 4-35 °C.
8. Fuel volume in the tank between 0-85 %. The engine control module (ECM) ignores these parameters if a diagnostic trouble code (DTC) is stored for the fuel level sensor and the fuel volume cannot be determined.
9. Battery voltage between 11-15 V. The voltage must be stable.
10. EVAP canister purge valve closed
11. Low volume in the canister.
12. Fuel tank filler cap locked. Tip. Locking occurs when the vehicle speed exceeds approximately 20 km/h.

Diagnostic phases

The diagnostic is divided into the following phases and is carried out in sequence when all conditions for the diagnostic have been met.

1. reference phase
2. function test
3. checking the fuel tank system

Reference phase

Before the leak diagnostic begins, the control module runs a reference phase for leakage. During the reference phases for leakage that is 0.5 mm, the pump in the leak diagnostic unit pumps ambient air through a 0.5 mm hole and back out to the ambient air. At the same time, the pump in the leak diagnostic unit is monitored and the reference values stored for later use to determine whether the tank system is leaking or not.

If a reference value for the pump is outside its unexpectedly high or low, or deviates too much, diagnostics is cancelled and a DTC is stored.

Function test

After the reference phase, the valve in the leak diagnostic unit is activated and controls the air flow to the fuel tank to pressurize the fuel tank system. This change of air flow will cause the load the pump to fall briefly before the pressure builds up in the fuel tank system. If the load does not change within permitted parameters within a permitted time, diagnostics is cancelled and a DTC is stored.

Checking the tank system, major leak (leak greater than 1.0 mm)

Diagnostics are carried out every time conditions for diagnostics are met.

The leak diagnostic unit pressurizes the fuel tank system and checks for leaks by monitoring the pressure the fuel tank system. The pressure is a calculated pressure, calculated using the measured pump power consumption. If the pressure stabilises and/or does not exceed 1500 Pa within 450 seconds, this is interpreted as a leak from the fuel tank system. Diagnostics are cancelled and a DTC for major leak is stored.

Checking the fuel tank system, minor leak (leakage greater than 0.5 mm but less than 1.0 mm)

The diagnostic for minor leaks is run every other time that the conditions for the diagnostic are met. Otherwise diagnostics stop after checking for major leaks.

The leak diagnostic unit continues to pressurize the fuel tank system. The Engine control module (ECM) checks for leakage in the fuel tank system by measuring the relationship between reached pressure and flow from the leak diagnostic pump during pressurization. In a sealed system the relationship between these must be linear. Any deviations from the linear relationship are calculated and used to determine how well sealed the tank system is.

A diagnostic trouble code (DTC) is stored if a minor leak is detected within 15 minutes.

Scheme 301

All gases that evaporate from fuel in the fuel tank must be led to and stored in the evaporative emission system (EVAP) canister so that they can be directed into the engine for combustion. In order to detect leakages that cause gas to evaporate into the air, the fuel tank system is diagnosed for leakage. The fuel tank system consists of fuel tank, , fuel filler pipe (7), EVAP canister (2), EVAP valve (1), air cleaner (4), leak diagnostic unit (3) and all cables between these components. The fuel tank system has a leak diagnostic unit that makes it possible to diagnose any leaks. The unit pressurizes the fuel tank system when the ignition is switched off if the conditions for leak diagnostics are met. The control module can detect faults in the function of the diagnostic unit and leakage that is 0.5 mm (minor leak) or greater (major leak, fuel filler cap missing).

The leak diagnostic unit consists of a pump and a valve that controls the air flow in the unit. The fuel tank system tests for leaks by measuring the power consumption of the pump. The power consumption of the pump corresponds to a certain pressure in the fuel tank system. During diagnosis, the rate at which the pressure can build up is checked, taking into account the quantity of fuel in the tank. The quicker the pressurization the better the fuel tank system is sealed.

Conditions for diagnosis

The diagnosis begins when all the following conditions are met

1. There must be no diagnostic trouble code (DTC) stored for the following components or functions: the power stage for the pump in the leak diagnostic unit the power stage for the valve in the leak diagnostic unit the power stage for the EVAP canister purge valve the EVAP canister purge valve.
2. Engine off for at least 5 hours (context), engine running for at least 20 minutes (context)
3. Ignition off
4. Vehicle speed 0 km/h
5. Engine coolant temperature (ECT) +4 °C or higher
6. Maximum altitude of 2500 meters above sea level
7. Outside temperature between +4 and +35 °C
8. Stable signal from the fuel level sensor
9. Fuel volume in the tank between 15-85 %
10. Battery voltage between 11.0-14.5 V. The voltage must be stable
11. EVAP canister purge valve closed
12. Low volume in the canister.

Diagnostic phases

The diagnostic is divided into the following phases and is carried out in sequence when all conditions for the diagnostic have been met.

1. Reference phase 1
2. Function test
3. Leak diagnostic.

Reference phase and function test

Scheme 302

(the illustration is a diagram of a fault free fuel tank system) Before the actual leak diagnostic begins, the control module enters a reference phase for leakage and checks the components in the system.

Reference phase 1 and reference phase 2

During the reference phases (1-2) for leakage that is 0.5 mm, the pump in the leak diagnostic unit pumps ambient air through a 0.5 mm hole and back out to the ambient air. At the same time, the power consumption of the pump is measured and stored in the control module (A). The stored value for the power consumption of the pump corresponds to a leakage of 0.5 mm.

Function test

If the value for the power consumption of the pump is too high or low during reference phase1 (1-2), or if the value varies too much during reference phase 1 (1-2), the diagnostic is cancelled and starts again the next time the conditions for the diagnostic are met. Diagnostic trouble code (DTC) ECM-431D, faulty signal, is stored if the diagnostic is cancelled 10 times due to excessive variation in the power consumption of the pump.

After the reference phase, the valve (2) in the leak diagnostic unit is activated and controls the air flow to the fuel tank to pressurize the fuel tank system. This change of air flow will cause the power consumption of the pump to fall briefly before the pressure builds up in the fuel tank system (3). Diagnostic trouble code (DTC) ECM-431D, signal missing, is stored if the value for the power consumption of the pump drops too quickly, too slowly or not at all.

Leak diagnostic

Scheme 303

(the illustration is a diagram of a fault free fuel tank system). As long as diagnostic trouble code (DTC) ECM-431D is not stored, the leak diagnostic will be carried out after the reference phase and the function test.

Major leak

(leaks >1.0 mm) The diagnostic for "major leaks" is carried out every other time when the diagnostic conditions are met. The leak diagnostic unit pressurizes the fuel tank system, measures the power consumption of the pump (4) and compares this with a calculated desired value (B). If the measured value does not reach the calculated desired value within a certain amount of time (this time is determined by the fuel level in the tank), the function of the leak diagnostic unit is rechecked by running reference phase 2 again to check that low power consumption has not led to changes in the components. Diagnostic trouble code ECM-400C, major leak, is generated if the power consumption of the pump is OK during reference phase 2.

Diagnostic trouble code (DTC) ECM-4338 (fuel tank filler cap missing) will also be stored and the driver will receive a text message in the Driver Information Module (DIM) when a major leak is detected by the Engine Control Module (ECM).

Minor leak

Scheme 304

(leaks >0.5 mm <1.0 mm). The diagnostic for "minor leaks" is carried out every 14th time when the diagnostic conditions are met. The diagnostic for major leaks is always run before the diagnostic for minor leaks. The leak diagnostic unit continues to pressurize the fuel tank system (5). If the measured value (6) is the same or less than the value stored in the reference phase (A) after a certain amount of time (determined by the fuel level in the tank), reference phase 2 (7) is run to ensure that the lower power consumption (6) is not the result of changes in components. If the measured power consumption during the second reference phase (7) is lower than that measured during pressurization (6), the control module interprets this as meaning that the fuel tank system is sealed. Diagnostic trouble code ECM-400C, minor leak, is generated if the measured power consumption from the second reference phase (7) is the same or higher than that measured during pressurization (6).

Scheme 305

All gases that evaporate from fuel in the fuel tank must be led to and stored in the evaporative emission system (EVAP) canister so that they can be directed into the engine for combustion. In order to detect leakages which cause evaporation of gases into the air, the fuel tank system is diagnosed for leakage. The fuel tank system consists of

1. fuel tank
2. the EVAP canister purge valve (1)
3. EVAP canister (2)
4. leak diagnostic unit (3)
5. air cleaner (ACL) (4)
6. Roll-over valve (5)
7. Float Limit Vent Valve (6)
8. fuel filler pipe (7)
9. all lines between the above components.

The fuel tank system has a leak diagnostic unit to diagnose any leakage. The leak diagnostic unit pressurizes the fuel tank system when the ignition is off, if the conditions for diagnosis have been met. The control module can detect faults in the function of the leak diagnostic unit and leakage that is 0.5 mm or greater. Minor leak; leakage greater than 0.5 mm but less than 1.0 mm. Major leak; leakage greater than 1.0 mm.

The leak diagnostic unit consists of a pump and a valve that controls the air flow in the unit. The fuel tank system tests for leaks by measuring the power consumption of the pump. The power consumption of the pump corresponds to a certain pressure in the fuel tank system. During diagnosis, the rate at which the pressure can build up is checked, taking into account the quantity of fuel in the tank. The quicker the pressurization the better the fuel tank system is sealed.

Conditions for diagnosis

The diagnosis begins when all the following conditions are met

1. There must be no diagnostic trouble code (DTC) stored for the following components or functions: the power stage for the pump in the leak diagnostic unit the power stage for the valve in the leak diagnostic unit the power stage for the EVAP canister purge valve the evaporative emission system (EVAP) valve the engine coolant temperature (ECT) sensor speed signal.
2. The engine is switched off until the engine coolant temperature (ECT) has fallen to a few degrees above the outside temperature, then engine running for at least 10 minutes
3. Ignition off
4. Vehicle speed 0 km/h
5. Engine coolant temperature (ECT) -5 °C or higher
6. Maximum altitude of 2500 meters above sea level.
7. Outside temperature between -5 and +35 °C
8. Fuel volume in the tank less than 85 %. The engine control module (ECM) ignores these parameters if a diagnostic trouble code (DTC) is stored for the fuel level sensor and the fuel volume cannot be determined
9. Battery voltage between 11.0-14.5 V. The voltage must be stable
10. EVAP canister purge valve closed
11. Low volume in the canister.

Fuel tank filler cap check

The exception from the above conditions is when the car has been refuelled. The engine control module (ECM) starts a check of the fuel tank filler cap after refuelling. This check is a simplified version of the leak diagnostic unit for major leaks. The fuel tank filler cap control is run whilst the vehicle is being driven. This allows the control module to check that the cap has been reinstalled. A diagnostic trouble code (DTC) is stored in the engine control module (ECM) and a text message is displayed in the driver information module (DIM) if the cap is missing.

Diagnostic phases

The diagnostic is divided into the following phases and is carried out in sequence when all conditions for the diagnostic have been met.

1. Reference phase
2. Function test
3. Leak diagnostics

Reference phase (1-2)

The illustration is a diagram of a fault free fuel tank system.

Before the leak diagnostic begins, the control module runs a reference phase for leakage. During the reference phase (1-2) for leakage that is 0.5 mm, the pump in the leak diagnostic unit pumps ambient air through a 0.5 mm hole and back out to the ambient air. At the same time, the power consumption (A) of the pump is measured and stored in the control module. The stored value (A) for the power consumption of the pump corresponds to a leakage of 0.5 mm. This value is then used by the engine control module (ECM) to determine the leak status of the fuel tank system.

Function test (1-3)

If the value for the power consumption of the pump is too high or low during the reference phase (1-2), or if the value varies too much during the reference phase (1-2), the diagnostic is cancelled and starts again the next time the conditions for the diagnostic are met. A diagnostic trouble code (DTC) is stored if the diagnostic is cancelled several time in a row because the power consumption of the pump is varying excessively.

After the reference phase, the valve (2) in the leak diagnostic unit is activated and controls the air flow to the fuel tank to pressurize the fuel tank system. This change of air flow will cause the power consumption of the pump to fall briefly before the pressure builds up in the fuel tank system (3). A diagnostic trouble code is stored if the value for the power consumption of the pump drops too quickly, slowly or not at all.

Leak diagnostic, major leak (leakage greater than 1.0 mm)

The diagnostic for "major leaks" is carried out each time when the conditions for the diagnostic are met. The leak diagnostic unit pressurizes the fuel tank system, measures the power consumption of the pump (4) and compares this with a calculated desired value (B). A diagnostic trouble code (DTC) for a major leak is stored if the measured value does not reach the calculated desired value within a certain time (the time is determined by atmospheric pressure and the fuel level in the tank).

Leak diagnostic, minor leak (leakage greater than 0.5 mm but less than 1.0 mm)

The diagnostic for minor leaks is run every other time that the conditions for the diagnostic are met. The diagnostic for major leaks is always run before the diagnostic for minor leaks. The leak diagnostic unit continues to pressurize the fuel tank system (5-6). After a certain amount of time (the time varies depending on the fuel level in the tank), the engine control module (ECM) checks that the fuel tank system for leaks. This is determined based on

1. time
2. the measured reference current consumption of the pump (A)
3. the measured power consumption of the pump when the assessment is made
4. the shape and character of the current curve during pressurization.

A diagnostic trouble code (DTC) is stored if a minor leak is detected.