Fuel Injector 1 Control Circuit
This code indicates a fault in the control circuit for fuel injector 1.
Heads up: this code wasn't in our hand-written library yet, so DiagCoach AI built this page on the fly. Double-check critical specs against service info before condemning parts.
What it means (plain English)
The computer is seeing a problem with the voltage or current going to the fuel injector 1, which could be due to a bad injector, wiring issue, or a problem in the ECM itself.
What the computer is actually seeing
The ECU monitors the voltage and current feedback from injector 1's control circuit. If it detects values outside of expected ranges, it triggers this fault code.
What a healthy reading looks like
For a properly functioning circuit, you should see 12-14 volts when active and around 0 volts when inactive. The injector should activate in response to a pulse width signal typically ranging from 1 to 10 milliseconds.
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 wiring and connectors for fuel injector 1. Look for broken wires or corrosion.
- 22. Measure the voltage at the injector connector with the key on (engine off). Is it 12-14 volts? If not, trace back to the ECM.
- 33. If voltage is good, check the resistance of the injector. Disconnect the injector and measure between the terminals. It should be around 12-16 ohms.
- 44. If resistance is out of range, replace the injector. If resistance is fine, proceed to check the ECM output for injector 1.
- 55. Check the ECM output: using a scan tool, check if the ECM commands the injector to activate when the engine is cranked. If it doesn't, consider ECM replacement.
Common causes
- Faulty fuel injector
- Open or shorted wiring harness for injector 1
- Corroded connectors or poor electrical connections
- Defective ECM (Engine Control Module)
Typical repair cost
$$$
Related codes
Frequently asked questions
Is it safe to drive with this code present?
It's best to fix this soon as it affects engine performance, but you might be able to drive short distances at low speeds.
Will this code return after repair?
If the repair is done correctly, it should not come back unless there's another underlying issue.
Why does this code pair with other injector codes?
These codes are often related as multiple injectors share similar electrical circuits or the same control module.
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