Cylinder 1 Injector Circuit Low Voltage
Low voltage detected in the circuit for cylinder 1 injector.
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What it means (plain English)
The computer sees that the electrical signal to the injector for cylinder 1 is below an acceptable level, which can prevent the injector from opening properly to deliver fuel.
What the computer is actually seeing
The ECM measures the voltage at the cylinder 1 injector circuit and detects a voltage drop below a threshold, typically around 4.5 volts. This indicates a problem in the power or ground side of the injector circuit.
What a healthy reading looks like
Normal injector operation should show a voltage between 12 volts (battery voltage) and around 4.5 volts when the injector is commanded to open.
Guided diagnostic — the DiagCoach way
Don't just throw parts at it. Walk through these in order — each step tells you whether to keep going or stop and fix what you found.
- 11. Inspect the wiring and connectors at the cylinder 1 injector for damage or corrosion. Fix any issues found.
- 22. Check the voltage supply to the injector circuit. With the engine running, measure the voltage at the injector connector. Should be 12 volts or close to it.
- 33. Disconnect the injector and test resistance across its terminals. Expected resistance should be between 12 to 16 ohms.
- 44. If injector tests okay, check the ground circuit for the injector. Confirm continuity to the ECM and ground points.
- 55. If all tests pass, suspect a faulty ECM.
Common causes
- Faulty injector
- Wiring issues (broken or shorted wire)
- Bad connector or corroded terminals
- Faulty ECM
Typical repair cost
$$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It's not recommended to drive, as it can lead to engine misfires and further damage.
Will the code come back after clearing?
If the underlying issue isn't resolved, the code will likely return.
Why does this code appear with other injector codes?
Multiple injector codes can indicate a common issue like wiring problems or a fault in the ECM.
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