Signal Specification, Model Year Up To 1999 Inclusive

Connector A, terminals #A1-#A24

All values given below are between the respective terminal in column 1 and terminal #A13 (signal ground). If this is not the case it is indicated in parentheses.

NOTE:

It is important to connect the breakout box and check ground terminals before reading off.

U=	DC voltage in volts (V)	U_AC =	Alternating current in volts (V)
U_bat =	Battery voltage	f =	Frequency in Hertz (Hz)
U_low =	Voltage approximately 0 V	%duty =	Duty cycle (pulse ratio) as a percentage (%)
t =	Time in milliseconds (ms)

Terminal in the breakout box	Terminal	Signal type	Ignition on	Engine idling	Other
1	#A1	Washer reservoir level	Lamp lit: U= 2V Lamp not lit: U = 10 - U_bat	Lamp lit: U= 2V Lamp not lit: U = 10 - U_bat	-
2	#A2	ABS warning lamp	Lamp lit: U = 6 - 8V Lamp not lit: U = U_low	Lamp lit: U = 7 -10V Lamp not lit: U = U_low	-
3	#A3	Program selector signal "B"	Low: U = U_low with the switch in position for: - Speed warning - Average speed - Outside temperature - Mileage U = 10-12V in other positions		When the switch is disengaged: U=10-12V
4	#A4	Left turn signal lamp	Lamp not lit: U = U_low Lamp lit: U = 8 - 12 V	Lamp not lit: U = U_low Lamp lit: U = 8 - 14 V	-
5	#A5	Program selector, signal "C"	Low: U = U_low with the switch in position for: - Speed warning - Average speed - Present fuel consumption Average fuel consumption U = 10-12V in other positions		When the switch is disengaged: U=10-12V
6	#A6	Program selector, signal "A"	Low: U = U_low with the switch in position for: - Speed warning - Present fuel consumption - Outside temperature - Range to empty fuel tank U = 10-12V in other positions		When the switch is disengaged: U=10-12V
7	#A7	Right turn signal lamp	Lamp not lit: U = U_low Lamp lit: U = 8 - 12 V	Lamp not lit: U = U_low Lamp lit: U = 8 - 14 V	-
8	#A8	Spare lamp	Not used	Not used	-
9	#A9	Rheostat	U ≈ 2V (rheostat min) U ≈ 10 - 12V (rheostat max)	U ≈ 2.3V (rheostat min) U≈U_bat (rheostat max)	-
10	#A10	Battery voltage 30+	U = U_bat	U = U_bat	-
11	#A11	Trip computer reset button	Not pressed: U=10-12V Pressed: U = Ulow		-
12	#A12	Outside temperature (-)	U = U_low	U = U_low	-
13	#A13	Signal ground 31-	U = U_low	U = U_low	-
14	#A14	Front fog lamp bulb	Lamp not lit: U = U_low Lamp lit: U = 10 - 12 V	Lamp not lit: U = U_low Lamp lit: U = 12 - 14 V	-
15	#A15	Trailer	Lamp lit: U = U_bat	Lamp lit: U = U_bat	-
16	#A16	Fog tail lamps	Lamp not lit: U = U_low Lamp lit: U = 10 - 12 V	Lamp not lit: U = U_low Lamp lit: U = 12 - 14 V	-
17	#A17	Battery voltage 15+	U = U_bat	U = U_bat	-
18	#A18	Cruise control	Lamp lit: U = U_bat	Lamp lit: U = U_bat	-
19	#A19	Outside temperature (+)	Infocenter and alternative: -40 °C ≈ 4.9V -20 °C ≈ 4.2V -10 °C ≈ 3.8V -5 °C ≈ 3.5V 0 °C ≈ 3.25V 3 °C ≈ 3.0V 5 °C ≈ 2.9V 10 °C ≈ 2.65V 20 °C ≈ 2.15V 30 °C ≈ 1.65V 40 °C ≈ 1.3V 50 °C ≈ 1.0V Without infocenter: U = U_low	Without infocenter: U = U_low	Voltage increases linearly with falling temperature. Measured to A12 (ground). The lamp is permanently lit between +3 °C and -5 °C. The lamp is lit for 30 seconds if the temperature is lower than -5 °C. The lamp is unlit if the temperature is higher than +5 °C.
20	#A20	High beam	Off: U = U_low On: U = U_bat	Off: U = U_low On: U = U_bat	-
21	#A21	-	-	-	-
22	#A22	Warning	Lamp not lit: U = U_low Lamp lit: U = 9 - 11V	Lamp not lit: U = U_low Lamp lit: U = 9 - U_bat	-
23	#A23	-	-	-	-
24	#A24	Trip computer reset button	Not pressed: U = 10 - 12 V Pressed: U = U_low	Not pressed: U = 12 - 14 V Pressed: U = U_low	-

Connector B, terminals #B1-#B24

All values given below are between the respective terminal in column 1 and terminal #A13 (signal ground). If this is not the case it is indicated in parentheses.

NOTE:

It is important to connect the breakout box and check ground terminals before reading off.

U=	DC voltage in volts (V)	U_AC =	Alternating current in volts (V)
U_bat =	Battery voltage	f =	Frequency in Hertz (Hz)
U_low =	Voltage approximately 0 V	%duty =	Duty cycle (pulse ratio) as a percentage (%)
t =	Time in milliseconds (ms)

Terminal in the breakout box	Terminal	Signal type	Ignition on	Engine idling	Other
31	#B1	High beam	Off: U = U_bat On: U = U_low	Off: U = U_bat On: U = U_low	-
32	#B2	Door switch	Closed door: U = 10 - 12 V Door open U = U_low	Closed door: U = 12 - 14 V Door open: U = U_low	-
33	#B3	Diagnostic lead	U ≈ 9 - 11 V	U ≈ 9 - 11 V	-
34	#B4	Output signal, vehicle speed signal to radio	U = U_low or 9 - U_bat (depending on the position of the right front wheel)	U = U_low or 9 - U_bat (depending on the position of the right front wheel)	-
35	#B5	Fuel consumption signal	U = U_low	f = 3-6 Hz Without infocenter: U = U_low	Only trip computer
36	#B6	Malfunction indicator lamp (MIL)	Lamp on: U = U_low	Lamp on: U = U_low	The lamp is lit in winter. The lamp flashes when there is a fault in the automatic transmission.
37	#B7	Engine speed signal (RPM)	U = U_low -9V	U= 9V f = 20-30 Hz	For Melco 2 systems, the engine speed (RPM) signal comes directly from the ignition sensor for the engine management system
38	#B8	Three-way catalytic converter (TWC) temperature	Lamp lit: U = U_low Lamp not lit: U = 12 - 14 V	Lamp lit: U = U_low Lamp not lit: U = 12 - 14 V	-
39	#B9	Fuel level	U = 0 - 5V, depending on the fuel level	U = 0 - 5V, depending on the fuel level	(measured to B17)
40	#B10	Engine coolant temperature (ECT)	For EMS2000: f = 45 Hz at +25°C f = 20 Hz at +100°C For MELCO 1 and Fenix 5.1: U = 0 - 5 V depending on the engine coolant temperature (ECT)	For EMS2000: f = 45 Hz at +25°C f = 20 Hz at +100°C For MELCO 1 and Fenix 5.1: U = 0 - 5 V depending on the engine coolant temperature (ECT)	For EMS2000: A pulsed signal between 0 V and 5 V with variable frequency and fixed pulse ratio (%duty). f increases with decreasing temperature. For MELCO 1 and Fenix 5.1: Separate sensor for the combined instrument panel.
41	#B11	SRS system	Lamp lit: U ≈ 6 - 8 V Lamp not lit: U = U_low -2V	U ≈ 7 - 9 V	-
42	#B12	Signal at high temperature	Lamp lit: U = U_low Lamp not lit: U = U_bat Gasoline driven cars: U = U_low	Lamp lit: U = U_low Lamp not lit: U = U_bat Gasoline driven cars: U = U_low	The connector is grounded when the diesel engine temperature is >120°C
43	#B13	Battery charging	U = U_low	U = 13 -14 V,	When the lamp is ON the low fuel level, the temperature too high LED and the brake fluid lamp light up.
44	#B14	Brake fluid level sensor	U = 0 - 5 V,	U = U_bat Lamp not lit:	-
45	#B15	Speed output signal	U = U_low or 9 - U_bat (depending on the position of the right front wheel)	U = U_low or 9 - U_bat (depending on the position of the right front wheel)	-
46	#B16	Speedometer input signal	U = U_low or 9 - U_bat (depending on the position of the right front wheel)	U = U_low or 9 - U_bat (depending on the position of the right front wheel)	-
47	#B17	Signal ground for fuel level and coolant temperature sensor	U = U_low	U = U_low	The engine coolant temperature (ECT) for diesel is not grounded via terminal #B17.
48	#B18	Bulb failure warning sensor	Lamp not lit: U = U_bat Lamp lit U = U_low	Lamp not lit: U = U_bat Lamp lit U = U_low	-
49	#B19	Parking brake	Engaged: U = U_low Disengaged: U = U_bat	Engaged: U = U_low Disengaged: U = U_bat	-
50	#B20	Oil pressure sensor	Lamp lit: U = U_low	Lamp not lit: U = U_bat	-
51	#B21	Seat belt	Lamp lit: U = 12 - 14 V_bat Lamp not lit U = U_low	Lamp lit: U = 12 - 14 V_bat Lamp not lit U = U_low	Lamp flashes (f = 3 Hz).
52	#B22	Spin or glow system	Lamp not lit: U = U_bat Lamp lit U = U_low	Lamp not lit: U = U_bat Lamp lit U = U_low	Spin for gasoline engines Glow for diesel engines:
53	#B23	Malfunction indicator lamp (MIL)	Lamp not lit: U = U_bat Lamp lit U = U_low	Lamp not lit: U = U_bat Lamp lit U = U_low	-
54	#B24	Immobilizer warning lamp	Lamp lit: U = U_low	Lamp lit: U = U_low	-