LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Volvo >> 2000 >> S80 Base >> Repair and Diagnosis >> Engine Performance >> Engine Control Systems >> Ignition And Control Systems - Specifications, Electrical/Electronic >> Signal Description, Engine Control Module (ECM) (B5254T2; 2004) >> Signal description >> Notes
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Signal description: Notes

General 

All values stated below are measured between each connection in column 1 (Conn. control module) and breakout box connection #B3 unless otherwise noted in column 6 (Other). The control module's connections #A1-#A70 correspond to #A1-#B10 on the breakout box, #B1-#B50 correspond to #B11- #B60 on the breakout box.

NOTE: It is important to connect the breakout box and check the ground connections before starting to measure.

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

U= DC voltage in volts (V) UAC = AC voltage in volts (V)
Ubat = Battery voltage (V) f = Frequency in Hertz (Hz)
Ulow = Voltage approximately 0 V % duty = Duty cycle (pulse ratio) in percent (%)
t = Time in milliseconds (ms) I = Current in amperes (A)
Control module terminal  Breakout box terminal  Signal type  Ignition on  Engine idling  Other 
#A1 #A1 Signal electronic throttle module, potentiometer 1 (circuit 1) U ≈ 0.4 - 4 V - The voltage varies depending on the position of the throttle. U increases with increased throttle opening.
#A2 #A2 Fuel pressure sensor signal - 350-400 kPa (absolute pressure) U = 1.8 - 2 V The voltage increases with increased fuel pressure.
#A3 #A3 Fuel temperature sensor signal - U≈ 0.5 - 4.5 V Voltage drops with increased fuel temperature. The fuel temperature sensor is integrated in the fuel pressure sensor.
#A4 #A4 Signal engine temperature sensor - (+30°C) U = 1.22 V
(+80°C) U = 0.29 V
(+100°C) U = 0.17 V
-
#A5 #A5 Intake air temperature (IAT) sensor signal - (+20°C) U = 3.50 V
(+30°C) U = 3.00 V
(+40°C) U = 2.50 V
Air temperature sensor inlet is integrated in boost pressure sensor.
#A6 #A6 Control signal preheating rear heated oxygen sensor U = Ubat Preheating of: U=Ubat
Preheating on: U=Ulow
-
#A7 #A7 Engine cooling fan (FC) control signal Pulse width modulation (PWM) signal
Uhigh min. 70% of Ubat
Ulow =1.2 V
f = 100 Hz
Pulse ratio= 10-95%
- -
#A8 #A8 - - - -
#A9 #A9 Control signal EVAP-valve U = Ubat - PWM signal during activation of the canister purge (CP) valve
#A10 #A10 - - - -
#A11 #A11 - - - -
#A12 #A12 - - - -
#A13 #A13 Control signal, intake camshaft reset valve - Pulse width modulation (PWM) signal
Utop =Ubat
f = 250 Hz (12.5 Hz)
Pulse ratio 20-95%
Pulse ratio controls control of the camshaft
#A14 #A14 Control signal injector no. 5 U = Ubat t = 2-3 ms t increases with engine speed (RPM) and load
#A15 #A15 Control signal injector no. 3 U = Ubat t = 2-3 ms t increases with engine speed (RPM) and load
#A16 #A16 Control signal injector no. 1 U = Ubat t = 2-3 ms t increases with engine speed (RPM) and load
#A17 #A17 Power supply U = Ubat - Supplied via system relay
#A18 #A18 Control signal preheating front heated oxygen sensor U = Ubat Preheating of: U=Ubat
Preheating on: U=Ulow
-
#A19 #A19 Signal ground electronic throttle module, potentiometer 1 and 2 U=Ulow - -
#A20 #A20 Signal electronic throttle module, potentiometer 2 (circuit 2) U≈4-0.4 V - The voltage varies depending on the position of the throttle. U decreases with increasing throttle opening.
#A21 #A21 Exhaust camshaft reset valve control signal - Pulse width modulation (PWM) signal
Utop =Ubat
f=250 Hz (12.5 Hz)
Pulse ratio 20-95%
Pulse ratio controls control of the camshaft
#A22 #A22 Mass air flow (MAF) sensor signal U = 1 V U = 1.7 V U increases with increasing air mass
#A23 #A23 Signal boost pressure sensor U = 1.96 V - U increases with increasing boost pressure.
#A24 #A24 Front heated oxygen sensor (HO2S), pump current - - Pulsed current measurement, not measured
#A25 #A25 - - - -
#A26 #A26 Oil pressure switch signal U=Ulow U = Ubat -
#A27 #A27 Signal camshaft sensor 2, camshaft exhaust U = 5 V U = Pulsed signal
Utop = 5 V
Uoffset = 2.5 V
The frequency varies according to engine speed (RPM)
#A28 #A28 Front heated oxygen sensor (HO2S), calibration current - - Not measured
#A29 #A29 Voltage feed 5 V camshaft sensor U = 5 V - -
#A30 #A30 Control signal ignition coil no. 2 U=Ulow U = 2.5 V
thigh = 2 ms
The frequency varies according to engine speed (RPM)
#A31 #A31 Control signal ignition coil no. 1 U=Ulow U = 2.5 V
thigh = 2.5 ms
The frequency varies according to engine speed (RPM)
#A32 #A32 - - - -
#A33 #A33 Control signal injector no. 4 U = Ubat tlow =2-3 ms t increases with engine speed (RPM) and load
#A34 #A34 Control signal injector no. 2 U = Ubat tlow =2-3 ms t increases with engine speed (RPM) and load
#A35 #A35 Control signal (+) electronic throttle module's damper motor - Pulse width modulation (PWM) signal
Utop =Ubat
Pulse ratio 0-100%
The polarity of the control signal switches when the damper motor is to be controlled in the opposite rotational direction.
The damper motor is controlled using a PWM-signal from the integrated end-stage in the engine control module (ECM) measured to #A36 (#A36)
#A36 #A36 Control signal (-) electronic throttle module's damper motor - Pulse width modulation (PWM) signal
Utop =Ubat
Pulse ratio 0-100%
The polarity of the control signal switches when the damper motor is to be controlled in the opposite rotational direction.
The damper motor is controlled using a PWM-signal from the integrated end-stage in the engine control module (ECM) measured to #A35 (#A35)
#A37 #A37 - - - -
#A38 #A38 Control signal turbo control valve U = Ubat - For turbo control: PWM-signal
f= 32 Hz
#A39 #A39 Voltage feed 5 V
boost pressure sensor, AC pressure sensor, mass airflow sensor
U= 5 V - -
#A40 #A40 - - - -
#A41 #A41 Signal (+) front heated oxygen sensor - - Pulsed current signal, not measured
#A42 #A42 Signal (-) front heated oxygen sensor - - Pulsed current signal, not measured
#A43 #A43 - - - -
#A44 #A44 - - - -
#A45 #A45 Signal (+) rear knock sensor U=Ulow - -
#A46 #A46 Signal (+) front knock sensor U=Ulow - -
#A47 #A47 Signal camshaft sensor 1, camshaft intake U = 5 V U = Pulsed signal
Utop =5 V
Uoffset = 2.5 V
The frequency varies according to engine speed (RPM)
#A48 #A48 Signal (+), flywheel sensor U = 2.5 V U = sinus voltage
Utop = 5 V
Uoffset = 2.5 V
Measured to #A66 (#B6)
The frequency increases with engine speed (RPM)
#A49 #A49 - - - -
#A50 #A50 Control signal ignition coil no. 3 U=Ulow U = 2.5 V
thigh = 2 ms
The frequency varies according to engine speed (RPM)
#A51 #A51 Control signal ignition coil no. 5 U=Ulow U = 2.5 V
thigh = 2 ms
The frequency varies according to engine speed (RPM)
#A52 #A52 Control signal ignition coil no. 4 U=Ulow U = 2.5 V
thigh = 2 ms
The frequency varies according to engine speed (RPM)
#A53 #A53 Power ground 3 Ulow - Grounding point, connected to chassis
#A54 #A54 Power ground 2 Ulow - Grounding point, connected to chassis
#A55 #A55 - - - -
#A56 #A56 - - - -
#A57 #A57 - - - -
#A58 #A58 Signal ground mass airflow sensor U=Ulow - -
#A59 #A59 Voltage feed 5 V electronic throttle module, potentiometer 1 and 2 U = 5 V - -
#A60 #A60 Signal ground
AC pressure sensor, boost pressure sensor, engine temperature sensor
U=Ulow - -
#A61 #B1 Signal (+) rear heated oxygen sensor U≈0.50 V Above 0.6 V or below 0.3 V -
#A62 #B2 Signal (-) rear heated oxygen sensor U=Ulow U=Ulow -
#A63 #B3 Signal ground U=Ulow - Grounding point, connected to chassis
#A64 #B4 Signal (-) front knock sensor U=Ulow - -
#A65 #B5 Signal ground camshaft sensor U=Ulow - -
#A66 #B6 Signal (-) flywheel sensor U = 2.5 V U = sinus voltage
Utop = 5 V
Uoffset = 2.5 V
Measured to #A48 (#A48)
The frequency increases with increasing engine speed
#A67 #B7 Signal (-) rear knock sensor U=Ulow - -
#A68 #B8 Signal AC pressure sensor U = 0.9 V (at approximately 20°C) - U increases with increasing pressure in the AC-system
#A69 #B9 - - - -
#A70 #B10 - - - -
Control module terminal  Breakout box terminal  Signal type  Ignition on  Engine idling  Other 
#B1 #B11 Control modules communication cable (CAN L) - - -
#B2 #B12 - - - -
#B3 #B13 - - - -
#B4 #B14 Signal ground
clutch pedal sensor, outside temperature sensor
U=Ulow - -
#B5 #B15 Signal ground accelerator pedal sensor U=Ulow - -
#B6 #B16 - - - -
#B7 #B17 Control signal, leak diagnostic unit, pump Pump motor running: U=Ulow Pump motor not running: U = Ubat - -
#B8 #B18 Signal, coolant level sensor U=Ulow Low coolant level: U=Ubat
Normal coolant level: U= Ulow
-
#B9 #B19 Power supply, 5 V accelerator pedal (AP) position sensor U= 5 V - -
#B10 #B20 - - - -
#B11 #B21 30-supply (power supply from battery) U = Ubat U = Ubat Ignition off: U = Ubat
#B12 #B22 - - - -
#B13 #B23 Communication cable control module (CAN H) - - -
#B14 #B24 - - - -
#B15 #B25 Clutch pedal sensor signal Unaffected: U = 3.3 V
Fully depressed: 100 mm U = 2.2 V
- U varies depending on the position of the clutch pedal
#B16 #B26 - - - -
#B17 #B27 Signal, accelerator pedal (AP) position sensor U= 0.4 0.1 V for unaffected accelerator pedal
U= 2.5-4.4 V for fully depressed accelerator pedal
On certain vehicles, the accelerator pedal's position is all the way down before the signal reaches 4.4 V.
- U varies depending on the position of the accelerator pedal
#B18 #B28 - - - -
#B19 #B29 - - - -
#B20 #B30 - - - -
#B21 #B31 - - - -
#B22 #B32 Diagnostic lead C-link U= 90% of Ubat - Other values apply if a generic fault-tracing instrument is connected to the data link connector (DLC)
#B23 #B33 Signal crank, 50-supply U=Ulow U=Ulow At crank: U = Ubat
#B24 #B34 - - - -
#B25 #B35 Signal, accelerator pedal (AP) position sensor Utop = 12 V
t = 4 ms
pulse ratio= 8% 2% for unaffected accelerator pedal and 50% - 90% for fully depressed accelerator pedal
On certain vehicles, the accelerator pedal's position is all the way down before the signal reaches 90%.
- PWM-signal from the accelerator pedal position sensor to the engine control module
#B26 #B36 Brake lamp switch signal When brake pedal is actuated: U=Ubat
When brake pedal is not actuated U=Ulow
- -
#B27 #B37 - - - -
#B28 #B38 - - - -
#B29 #B39 Signal, outside temperature sensor (0°C) U = 2.92 V
(+10°C) U = 2.40 V
(+20°C) U = 1.90 V
(+30°C) U = 1.46 V
- Temperature range: -40 to +30°C
#B30 #B40 - - - -
#B31 #B41 - - - -
#B32 #B42 - - - -
#B33 #B43 - - - -
#B34 #B44 - - - -
#B35 #B45 - - - -
#B36 #B46 - - - -
#B37 #B47 Signal, ignition on, 15-supply U = Ubat U = Ubat Ignition off: U=Ulow
#B38 #B48 System relay, control signal - U=Ulow Relay activated: U=Ulow
Relay not activated: U=Ubat
The system relay has post-run time (2-5 min.)
#B39 #B49 - - - -
#B40 #B50 Control signal, leak diagnostic unit, valve - - Valve activated: U=U low
Valve not activated: U=U bat
#B41 #B51 - - - -
#B42 #B52 - - - -
#B43 #B53 - - - -
#B44 #B54 Control signal, air conditioning (A/C) relay - - AC-relay activated: U=Ulow
AC-relay not activated: U=Ubat
#B45 #B55 Fuel pump (FP) activation control signal - - PWM signal to the central electronic module (CEM) to control the fuel pump (FP) relay
#B46 #B56 Malfunction indicator lamp (MIL) control signal U=Ulow Not activated U=Ubat
Activated: U=Ulow
-
#B47 #B57 - - - -
#B48 #B58 Control signal, engine cooling fan (FC), control modules - Not activated U=Ubat
Activated: U=Ulow
The engine cooling fan (FC) is controlled by the engine control module (ECM)
#B49 #B59 - - - -
#B50 #B60 - - - -