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ABS Speed Sensor
Air Flow Meter / Sensor
Air Intake Pressure Sensor
Alternator Current and Voltage
Amplifier Earth
Camshaft Sensor
Carbon Canister Solenoid Valve
Crankshaft sensor
Coolant Temperature sensor
Diesel Glow Plugs
Digital ECM to Ignition Amplifier Signal
Distributor Pickup
Dual Trace
Electronic Fuel Pump
Exhaust Gas Recirculation
Idle Speed Control Valve
Knock Sensor
Lambda Sensor
MAP Sensor
Relative Compression
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Dual Trace - Primary Ignition vs Secondary Ignition Diagnostics

Testing Primary v Secondary shows the exact relationship between the ignition's primary circuit and the secondary output. The primary circuit transfers its characteristics into the secondary through 'mutual inductance' and will mirror the primary exactly.
The exact same burn time should be evident. A permanent or intermittent loss of the secondary will usually be due to a failing coil or HT (High Tension) voltage tracking to earth. Losing the primary will result in a total loss of HT voltage.

Technical Information
Please see individual waveform topics:

Ignition primary
Ignition secondary (king lead)

Dual Trace - Primary Ignition vs Injector Current Diagnostics

By observing the current drawn by the injector at the same time as monitoring the primary ignition trace, we can identify the cause of a non-start situation or sudden loss of power, causing the engine to stop. If the primary trace is absent, there will be no switching of the injectors as these two circuits are timed together while the loss of the injector current signifies that a fault has occurred within the injection circuit.
The frequency of the injection trace when compared to the primary signal will differ between sequential and simultaneous injection. Sequential having one pulse per 720°, while simultaneous will predominantly have two. Some simultaneous systems do however have a single pulse, but these are in the minority.

Technical Information
Please see individual diagnostics topics:

Ignition primary
Multi-point injector current

Dual Trace - Injector Voltage vs Injector Current Diagnostics

When monitoring the injectors using both voltage and amperage, we can see the time that the injector is physically open. The waveforms are pretty self explanatory.

Technical Information
Please see individual waveform topics:

Multi-point injector (voltage)
Multi-point injector (current)