Injector Circuit Low - Cylinder 4
The engine control module detects a low voltage in the injector circuit for cylinder 4.
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 thinks the injector for cylinder 4 isn't getting enough voltage, like when a light bulb dims because it’s not getting enough electrical power.
What the computer is actually seeing
The ECM looks for a voltage signal from the injector circuit; when the voltage drops below 5 volts, it triggers this code.
What a healthy reading looks like
Normal operating voltage for fuel injector circuits is typically between 12-14 volts; if voltage drops below 5 volts, the error triggers.
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. Check injector connector and wiring for damage or corrosion. If found, repair or replace as needed. Decision: If okay, proceed to step 2.
- 22. Measure the voltage at the injector connector with the engine running. You should see 12-14 volts. If not, there's an issue upstream. Decision: If voltage is okay, proceed to step 3.
- 33. Check resistance of the injector using a multimeter; it should be within manufacturer specs (usually 12-16 ohms). If resistance is outside this range, replace the injector. Decision: If resistance is okay, check the ECM.
- 44. Inspect the ECM; if no physical damage is found but issues persist, consider reprogramming or replacing the ECM.
Common causes
- Faulty fuel injector
- Open circuit in the wiring
- Bad connector or poor connection
- Failed ECM
- Corroded terminals or ground issues
Typical repair cost
$$$ (typically $200-$600)
Related codes
Frequently asked questions
Is it safe to drive with this code?
It’s drivable, but you might notice a rough idle, reduced power, or poor fuel economy. Fix it soon.
Will this code come back after clearing?
If the underlying issue isn't fixed, yes, it'll likely return.
Why does this code pair with other injector codes?
Codes for different injectors can appear together if there’s a common issue like a wiring fault or ECM problem.
Working a real vehicle right now?
Let DiagCoach walk you through it live with your specific symptoms, vehicle, and what you've already checked.
Start guided diagnostic →