1996 Peugeot 306, 1.6 (NFZ, TU5). Some Known Good Engine Management Signal Waveforms

As I've worked on this car a few times recently. I catalogued some of its waveforms.

Quite incomplete because I did not have unlimited time.

Engine management computer is a Bosch Motronic 5.1

If you want to read about reading trouble codes for this vehicle and ones like it, go here.

Slow press & depress sweep of the accelerator pedal.

Sensor pin, ECU pin, allocation

1. 12, supply (5 V)
2. 29, signal
3. 26, ground (< 0.1 V)

Fully closed: 0.3 V

Fully open: 5 V

Diagram code: 1317

Crankshaft position sensor.

1. Figure 1: idle, 2 rotations
2. Figure 2: idle, 1 rotation
3. Figure 3: 2000 rpm, 2 rotations

Sensor pin, ECU pin, allocation

1. 30, supply
2. 11, signal
3. 19, shield/ground

Idle peek-peek: 6 V

3000 rpm peek-peek: 17 V

Resistance between 1 and 2: 300 - 650 ohm

Diagram code: 1313

Coolant temperature sensor from cold to running.

Note thermostat blip near the end of the trace.

Sensor pin, ECU pin, allocation

1. 26, ground
2. 25, signal

Temp, Resistance, Volts

1. 100, 200, 0.3
2. 90, 250, 0.4
3. 80, 350, 0.6
4. 70, 450, 0.9
5. 30, 1900, 2.5
6. 20, 2500, 3.5
7. 10, 4500, 3.4
8. 0, 7200, 3.9

Diagram code: 1220

Note: air temperature sensor has same pins and values.

Manifold absolute pressure.

1. Figure 1: idle
2. Figure 2: idle - 2000 - idle
3. Figure 3: snap - stall
4. Figure 4: Start to idle

Sensor pin, ECU pin, allocation

1. 12, power (5 V)
2. 7, signal
3. 26, ground (< 0.1 V)

Idling: 1.2 V

Snap throttle: 4.4 V

Diagram code: 1312

Ignition input.

1. Figure 1: idle
2. Figure 2: idle single fire of both coils
3. Figure 3: 2000 rpm

Coil pin, other end pin, allocation

1. ECU 1, cylinders 1 & 4
2. ECU 20, cylinders 2 & 3
3. Ignition/injection relay (1304) pin 9
4. Ground to coil body

Coil resistances: Primary: 1 Ohm, Secondary: 8500 or 14500

Diagram code: 1135

Idle air controller.

1. Figure 1: Key on engine off
2. Figure 2: idle
3. Figure 3: 2000 rpm

Actuator pin, other end pin, allocation

1. ECU 33, duty cycle control
2. Ignition/injection relay (1304) pin 4
3. ECU 15, duty cycle control

Duty cycle at idle: 40 - 57%

Resistances: Pin 1 & 2 and 3 & 2: 10 - 15 ohm

Diagram code: 1239

Note: Cleaning often helps fix idle trouble.

Evap purge solenoid. Inactive.

Actuator pin, other end pin, allocation

1. ECU 5,
2. Ignition/injection relay (1304) pin 15

Idle: constant blipping of the solenoid, similar to IAC

Ignition on: battery voltage

Resistance: 50 ohm

Diagram code: 1215

Oxygen sensor (1340)

Sensor pin, other end pin, allocation

1. heater power fuse (1348)
2. ground
3. ECU 10, signal
4. ECU 28, ground

Voltage between pins 3 and 4 oscillates between 0.1 and 0.9 V. Normal heated O2 sensor behaviour.

Voltage between pins 1 and 2 should be pulse width controlled.

Resistance between pins 1 and 2: 4 - 5 ohm.

Vehicle speed sensor (1620)

Sensor pin, other end pin, allocation

1. Ignition/injection relay (1304) pin 6
2. ground
3. ECU 9, signal

Voltage varies with vehicle speed.

Injectors (1331 - 1334)

Actuator pin, ECU pin, allocation

1. Ignition/injection relay (1304) pin 13
2. ECU 17, control

Resistance: 16 ohm

Pin 2:

1. KOEO: battery voltage
2. idle: 2.1 ms solenoid pulse
3. 3000 rpm: 1.8 ms solenoid pulse