P22EC

Code

Generic P — Powertrain

Cylinder 5 Alternative Fuel Injector Control Circuit Range/Performance

Brand: Generic

Type: P — Powertrain

Views: UK: 25 EN: 24 RU: 22

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Page language: EN

Causes

Open or short in injector wiring (power, ground, or driver circuit)
Poor or corroded connector at cylinder 5 injector or fuel rail
Failed alternative-fuel injector (stuck, shorted coil, high resistance)
Faulty injector driver transistor or ECM output for cylinder 5
Wrong/unstable fuel system operation (pressure, delivery) for alternative fuel mode
Intermittent wiring damage from heat, chafing or engine movement

Symptoms

Rough idle or misfire when running on alternative fuel
Reduced power or hesitation under load
Engine warning lamp (MIL) illuminated
Hard starting or no start in alternative-fuel mode
Fuel smell from the engine bay (if leak present)
Possible increased emissions or failed emissions test

What to check

Read freeze frame and related codes; verify vehicle fuel mode at time of fault
Visually inspect cylinder 5 injector, connector, and harness for damage or corrosion
Check fuses and relays for alternative-fuel injector power circuit
Backprobe injector connector while cranking and/or running; compare signals to a known-good cylinder
Measure injector coil resistance (unplugged) and compare to vehicle specification
Perform voltage drop checks on power and ground circuits to the injector

Signal parameters

Injector supply voltage: near battery voltage with key ON (check actual spec for vehicle)
Driver output: switching between near-battery-voltage and near-ground when firing (pulse waveform)
Typical pulse width: varies with load and RPM; commonly from 1–10 ms (vehicle-specific)
Injector coil resistance: varies by injector design—consult vehicle spec. Expect a stable value; open or near-short values indicate failure
Compare cylinder 5 waveform, voltage and resistance to other cylinders for deviation

Diagnostic algorithm

Retrieve all stored codes and freeze-frame data. Note whether the vehicle was operating on the alternative fuel when the code set.
Visually inspect the injector harness, connector and engine area for heat damage, pin corrosion, or rodent damage. Repair any obvious issues.
With ignition OFF, disconnect the cylinder 5 injector and measure coil resistance across the injector terminals. Compare to vehicle specification and to another injector on the engine.
Check for proper battery voltage at the injector power feed with ignition ON. Turn off ignition before reconnecting.
Backprobe the driver pin at the injector connector with the engine cranking or running on the alternative fuel. Verify the driver is producing expected switching and compare to a known-good cylinder.
If waveform or voltage is abnormal at the connector but injector resistance is normal, perform wiring continuity and short-to-power/ground checks between the injector connector and the ECM pin. Repair wiring as needed.
Swap the cylinder 5 alternative-fuel injector with another cylinder (if identical) and see if the code and symptoms move with the injector. If they do, replace the injector.
If the issue follows the harness or stays with cylinder 5 ECM output, inspect ECM connector pins and consider ECM driver fault. Check for TSBs/ECM software updates before replacing ECM.
Verify alternative fuel system pressure and delivery are within specification; poor fuel supply can affect injector performance.
After repairs, clear codes and road-test in the alternative-fuel mode to confirm the fault does not return.

Likely causes

Bad or corroded connector at the alternative-fuel injector on cylinder 5
Injector coil resistance out of spec (open or short)
Damaged wiring harness to cylinder 5 injector
Faulty injector driver in the ECM
Low or unstable alternative fuel pressure affecting injector response

Fault status

⚠️ Status

Cylinder 5 alternative-fuel injector control circuit performance out of expected range. ECM detected abnormal signal/response from the alternative-fuel injector on cylinder 5; may cause misfire, rough running or reduced power.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 0.5–2.0 hours