P0067 - Air Assisted Fuel Injector Control Circuit High
System
Powertrain (Engine & Gearbox)
Technical Description
The control module has detected a fault in the Air Assisted Fuel Injector Control Circuit High (P0067). The signal is above the upper threshold, typically from an open circuit, poor connection, or a short to battery voltage.
Multimeter Test Points & Nominal Values
| Test Point / Component | Measurement | Nominal Target Range | Test Condition |
|---|---|---|---|
| Air Assisted Fuel Injector Control Circuit High – Coil Resistance | Resistance (Ω) | 11.5 - 15.5 Ω (port) / 0.5 - 3.0 Ω (direct injection) | Connector disconnected at 20°C |
| Air Assisted Fuel Injector Control Circuit High – Injection Pulse at operating cycle | Signal (ms) | 2.5 - 4.5 ms idle / 1.5 - 20 ms under load | Engine running |
| Air Assisted Fuel Injector Control Circuit High – Supply Voltage | Voltage (V) | 11.8 - 14.4 V (port) / up to 65 - 90 V boost (direct) | Ignition ON / engine running |
Connector disconnected at 20°C
Engine running
Ignition ON / engine running
Oscilloscope Waveform Analysis
1 ms/div, 20 V/divPossible Causes
Open circuit on signal wire, spread terminal pin, or short to power feed at Air Assisted Fuel Injector Control Circuit High
Chafed or pinched wiring harness along the signal path to Air Assisted Fuel Injector Control Circuit High
Internal mechanical wear or carbon deposits inside Air Assisted Fuel Injector Control Circuit High
Defective internal output driver or reference circuit in the control module for Air Assisted Fuel Injector Control Circuit High
Symptoms
4
Recommended Solution
Measure signal terminal voltage with ignition ON and sensor unplugged to determine if ECM pull-up is active or harness is shorted to 12V.
Verify loaded supply voltage and harness terminal pins at Air Assisted Fuel Injector Control Circuit High.
Check circuit continuity and ground-side voltage drop (< 0.05 V) for Air Assisted Fuel Injector Control Circuit High.
Perform fuel rail pressure-drop / balance test to identify leaking, stuck, or clogged injectors.
Mechanic's Tip
Pair a current clamp with your voltage channel on the scope. The distinct dip in the current ramp marks the physical pintle lift — no dip means the coil is energized but the needle is mechanically seized.