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Engine Control Module (ECM) Diagnostic Trouble Codes (DTC) - 3 of 14: Overview Volvo V70 II

Description of diagnostic trouble code (DTC) status

The purpose of "Reading off the diagnostic trouble code (DTC) status" is to determine whether the diagnostic trouble code (DTC) is permanent or intermittent. Because of the different criteria for diagnostics, the text message "Diagnostic function not ready" may appear when reading off.

Below is an explanation of the different statuses which may occur.

Diagnostic function not ready

To run a diagnostic, all conditions must be met for the test of the relevant component or sub-system. For certain components/sub-systems, switching on the ignition is sufficient to run the diagnostic. Other require more specific conditions, such as engine speed and temperature etc.

This means for example, that diagnostics requiring an engine speed above 3000 rpm will never run on a stationary car when the engine is only idling. In such cases, where the diagnostic has not run in the present operating cycle, the test message "Diagnostic function not ready" will be displayed.

Permanent

If a diagnostic trouble code (DTC) with a permanent status is stored, the control module has registered a fault and the fault is still present.

Intermittent

If a diagnostic trouble code (DTC) with an intermittent status is stored, the control module has registered a fault and the fault is not present at the moment.

An intermittent electrical fault can be caused by faults in the wiring, components or connectors.

Intermittent functional faults could be caused by mechanical defects in the components.

Signal description

General

All values given below are between the terminals stated in column 1 and breakout box terminal #B2. Control module terminals #A1-#A60 correspond to terminals #A1-#A60 on the breakout box, terminals #A61-#A70 correspond to terminals #B1-#B10 on the breakout box and terminals #B1-#B50 correspond to terminals #B10-#B60 on the breakout box.

Note. It is important to connect the breakout box and check the ground terminals before taking readings.

HINT: If the numbering of the connector is different from the numbering on the breakout box, the connector number is given first, terminal #A61, followed by the breakout box number in brackets, (terminal #B1). Example: #A61 (#B1).

U=DC voltage in volts (V)U A/C =AC voltage in volts (V)
U bat =Battery voltage in volts (V)F =Frequency in Hertz (Hz)
U low =Voltage near 0V or 0V%pulse =Pulse ratio (%)
T =Time in milliseconds (ms)
TerminalBreakout boxSignal typeIgnition onIdling speedOther
#A1(#A1)
#A2(#A2)Control signal Canister purge (CP) valveU=UbatPWM signal during activation of the EVAP canister shut off valve
#A3(#A3)
#A4(#A4)Signal (+) intake temperature sensor, integrated in the mass air flow (MAF) sensor(+10 C) U= 2.01 V (+20 C) U=2.62 V (+30 C) U=3.21 V
#A5(#A5)Control signal engine cooling fan (FC) high-speedEngine cooling fan (FC) off U=Ubat Engine cooling fan (FC) on U=Ulow
#A6(#A6)Control signal engine cooling fan (FC) low-speedEngine cooling fan (FC) off U=Ubat Engine cooling fan (FC) on U=Ulow
#A7(#A7)
#A8(#A8)
#A9(#A9)
#A10(#A10)
#A11(#A11)Control signal preheating rear heated oxygen sensor (HO2S)U=UbatPreheating off U=Ubat Preheating U=Ulow
#A12(#A12)
#A13(#A13)
#A14(#A14)Control signal injector 5U=UbatT= 2-3msT increases with engine speed (RPM) and load
#A15(#A15)Control signal injector 3U=UbatTlow=2-3 msT increases with engine speed (RPM) and load
#A16(#A16)Control signal injector 1U=UbatTlow=2-3 msT increases with engine speed (RPM) and load
#A17(#A17)
#A18(#A18)Control signal preheating front heated oxygen sensor (HO2S)U=UbatPreheating off U=Ubat Preheating U=Ubat
#A19(#A19)
#A20(#A20)
#A21(#A21)Signal A/C pressure sensorU=0.9 V (at approximately 20 C)U increases with increased pressure in the system
#A22(#A22)Mass air flow (MAF) sensor signalU=0.58 VU=1.33 V Unloaded, engine at operating temperatureU increases with increasing air mass
#A23(#A23)Signal manifold absolute pressure (MAP) sensorU= 1.64 V atmospheric pressure at sea levelU increases with increasing pressure in the intake manifold
#A24(#A24)Signal (+) front heated oxygen sensor (HO2S) signal (+)Lambda=0.95 V>700 mV lambda=1.10 V<200 mV
#A25(#A25)
#A26(#A26)
#A27(#A27)
#A28(#A28)Signal ignition discharge module (IDM) check, ignition coils
#A29(#A29)Control signal ignition coil no. 3U=UlowU=2.5 volt thigh=2 msThe frequency varies according to engine speed (RPM)
#A30(#A30)Control signal ignition coil no. 2U=UlowU=2.5 volt thigh=2 msThe frequency varies according to engine speed (RPM)
#A31(#A31)Control signal ignition coil no. 1U=UlowU=2.5 volt thigh=2.5 msThe frequency varies according to engine speed (RPM)
#A32(#A32)
#A33(#A33)Control signal injector 4U=UbatTlow=2-3 msT increases with engine speed (RPM) and load
#A34(#A34)Control signal injector 2U=UbatTlow=2-3 msT increases with engine speed (RPM) and load
#A35(#A35)
#A36(#A36)Power ground preheating, front heated oxygen sensor (HO2S)U=Ulow
#A37(#A37)Communication cable control modules (CAN H)Between the engine control module (ECM) and the throttle unit
#A38(#A38)Control signal stop (brake) lamp - switchU=Ulow (not activated) U=Uhigh (activated)Between the engine control module (ECM) and the throttle unit
#A39(#A39)Oil pressure switchU=Ulow (no oil pressure)U=Ubat
#A40(#A40)Signal (+) Engine coolant temperature (ECT) sensor(+20 C) U=3.1 V (+30 C) U=2.6 V (+80 C) U=0.9 V (+100 C) U=0.5 V
#A41(#A41)Signal (-) front heated oxygen sensor (HO2S)Lambda=1 when the current is approximately +0.2 mANegative current when the fuel air mixture is rich. Range: -12 mA, +12 mA
#A42(#A42)Signal (+) front heated oxygen sensor (HO2S)Lambda=1 when the current is approximately +0.2 mAPositive current when the fuel air mixture is lean Range: -12 mA, +12 mA
#A43(#A43)
#A44(#A44)
#A45(#A45)
#A46(#A46)Signal (+) knock sensor (KS)
#A47(#A47)Signal (+) camshaft position (CMP) sensor
#A48(#A48)Signal (+) flywheel sensorU=2.5 VU=sine wave voltage Utop=3.5 V U offset=2.5 V
#A49(#A49)
#A50(#A50)Control signal ignition coil no. 5U=UlowU=2.5 volt thigh=2 msThe frequency varies according to engine speed (RPM)
#A51(#A51)Control signal ignition coil no. 4U=UlowU=2.5 volt thigh=2 msThe frequency varies according to engine speed (RPM)
#A52(#A52)Control signal Air assisted control valve (AACV)
#A53(#A53)Power ground 3Ulow
#A54(#A54)Power ground 2Ulow
#A55(#A55)Communication cable control modules (CAN L)Between the engine control module (ECM) and the throttle unit
#A56(#A56)Control signal accelerator pedal (AP) position sensor, PWM signalUtop=12 V t=4ms pulse ratio= 8%-88%Between the engine control module (ECM) and the throttle unit
#A57(#A57)Power supply, camshaft position (CMP) sensorU=5 volt
#A58(#A58)Power supply, manifold absolute pressure (MAP) sensor A/C pressure sensorU=5 volt
#A59(#A59)
#A60(#A60)Signal ground Mass air flow (MAF) sensorU=Ulow
#A61(#B1)Signal ground intake temperature Engine coolant temperature (ECT) sensor rear heated oxygen sensor (HO2S)U=Ulow
#A62(#B2)Power ground 1U=Ulow
#A63(#B3)
#A64(#B4)Signal (-) knock sensor (KS)
#A65(#B5)Signal ground camshaft position (CMP) sensorU=Ulow
#A66(#B6)Signal ground flywheel sensorU=Ulow
#A67(#B7)
#A68(#B8)
#A69(#B9)Control signal preheating front HO2SU=UbatPreheating off U=Ubat Preheating U=UbatB+ from the system relay
#A70(#B10)Power supplyU=UbatB+ from the system relay

Connector terminals #A1-#A70

TerminalBreakout boxSignal typeIgnition onIdling speedOther
#B1(#B11)Communication cable control modules (CAN L)Between the engine control module (ECM) and the CAN driver module
#B2(#B12)
#B3(#B13)
#B4(#B14)Signal ground intake air temperature (IAT) sensor fuel tank pressure sensor clutch pedal sensor brake pedal sensorU=Ulow
#B5(#B15)Signal ground accelerator pedal (AP) position sensorU=Ulow
#B6(#B16)
#B7(#B17)
#B8(#B18)Engine coolant level switchU=Ulow
#B9(#B19)Power supply accelerator pedal (AP) position sensor, analog sensorU=5 volt
#B10(#B20)Power supply fuel tank pressure sensorU=5 volt
#B11(#B21)30-supply (Power supply from the battery)U=Ubat
#B12(#B22)
#B13(#B23)Control modules communication cable (CAN H)Between the engine control module (ECM) and the CAN driver module
#B14(#B24)
#B15(#B25)Signal clutch pedal sensorU=3.3 V (unaffected) U=2.2 volt (fully depressed, 100 mm)Varies depending on the position of the clutch pedal
#B16(#B26)Signal brake sensorU=3.1 V (unaffected) U=2.6 V (25 mm depressed)Varies depending on the position of the brake pedal
#B17(#B27)Signal accelerator pedal (AP) position sensor, analog signalU=0.4 V (idle) U=4.4 V (wide open throttle (WOT))Varies depending on the position of the accelerator pedal (AP)
#B18(#B28)
#B19(#B29)Signal (+) cruise control SET+
#B20(#B30)Signal (+) cruise control RESUME
#B21(#B31)Output signal (+) engine speedU=UlowU=quadratic wave voltage Utop=UbatFrequency increases with engine speed (RPM)
#B22(#B32)Diagnostic lead C-linkU=90% of UbatIf a generic fault-tracing instrument is connected to the data link connector (DLC), other values apply
#B23(#B33)Signal (+) crank, +50 supplyU=UlowU=UlowU=Ubat at crank
#B24(#B34)
#B25(#B35)Signal (+) accelerator pedal (AP) position sensor, PWM signalUtop=Ubat T=4 ms pulse ratio= 8%-88%Between the accelerator pedal (AP) position sensor and the engine control module (ECM)
#B26(#B36Signal (+) Stop (brake) lamp switchU=Ubat when the brake pedal is depressed U=Ulow when the brake pedal is not depressed
#B27(#B37)Output signal Engine coolant temperature (ECT) to the air conditioning (A/C) systemUtop=Ubat T=4 ms pulse ratio = varies with engine coolant temperature (ECT)
#B28(#B38)
#B29(#B39)Signal outside temperature sensor(0C) U=2.34V (+10C) U=1.82 V (+20C) U=1.38 V (+25C) U=1.19 V (+30C) U=1.03 VTemperature range: -40C to +110C
#B30(#B40)
#B31(#B41)Signal fuel tank pressure sensorU=2.5 V at 1kPa negative pressure U=3.3 V at atmospheric pressure (0kPa overpressure) U=4.1 V at 1kPa overpressure
#B32(#B42)Signal A/C requestU=Ubat on request, otherwise U=Ulow
#B33(#B43)Signal cruise control on / offSee terminal #B47
#B34(#B44)Signal cruise control SETSee terminal #B47
#B35(#B45)
#B36(#B46)
#B37(#B47)Signal ignition on signal, +15 supplyU=Ubat
#B38(#B48)Control signal System relayU=UbatThe system relay runs on (2-15 mins)
#B39(#B49)
#B40(#B50)Control signal EVAP canister shut-off valveU=3.82 V
#B41(#B51)Control signal Electronic throttle system (ETS) warning lampU=UlowU=Ubat (not activated) U=Ulow (activated)
#B42(#B52)
#B43(#B53)
#B44(#B54)Control signal A/C activationU=Ubat (not activated) U=Ulow (activated)
#B45(#B55)Control signal fuel pump (FP) activation
#B46(#B56)Control signal malfunction indicator lamp (MIL)U=UlowU=Ubat (not activated) U=Ulow (activated)
#B47(#B57)Power supply Cruise ControlU=Ubat (not activated) U=pulse train Utop=Ubat t=20 ms thigh=0.5 ms
#B48(#B58)Control signal engine start inhibitingU=Ulow (activated) U=Uhigh (not activated)In certain markets, the engine can only be started with the clutch pedal depressed (U=Ulow)
#B49(#B59)
#B50(#B60)

Connector terminals #B1-#B50