P0207 — Injector Circuit — Cylinder 7
SevereQuick answer
P0207 means the engine computer has detected an electrical fault in the control circuit of the cylinder 7 fuel injector — an open, a short, or the wrong resistance. It’s a wiring-and-injector diagnosis, not a “dirty injector” code: check the connector and harness before buying parts.
What it means
The ECM opens each fuel injector by grounding its circuit for a precise number of milliseconds. While switching, it monitors the circuit electrically. P0207 sets when the circuit for the cylinder 7 fuel injector doesn’t behave — typically an open circuit (no current flows), a short, or resistance out of range.
This is different from a clogged injector: a clog changes how fuel flows but usually keeps the electrical side healthy. P0207 is about electrons, not fuel. That said, the end result overlaps — the cylinder runs lean or dead, so a misfire code (P0307) often comes along.
The injector solenoid itself, its two-pin connector, and the harness between the ECM and injector are the whole suspect list — plus a shared fuse/relay when multiple injector circuit codes appear together.
Common causes
Ordered from most to least likely.
- 1.
Failed injector solenoid (open or shorted winding)
Measure resistance and compare with a known-good cylinder — mismatch confirms it.
- 2.
Corroded or loose injector connector
Tiny two-pin connectors that take heat their whole lives; pins back out or corrode.
- 3.
Chafed or broken harness wiring
Especially where the harness crosses the fuel rail or a bracket.
- 4.
Blown injector fuse / failing relay
Suspect first when several injector circuit codes set at once.
- 5.
ECM driver failure
Rare; conclude only after injector, wiring, and supply all test good.
How to diagnose it, step by step
Cheapest and most likely checks first.
-
1 Scan for the pattern
One injector circuit code points at that cylinder’s injector/wiring; several at once point at shared power (fuse, relay, main harness). Note whether P0307 accompanies it.
-
2 Inspect the connector
Unplug the injector connector; look for corrosion, bent pins, and a loose lock. Clean with contact cleaner and re-seat firmly.
-
3 Measure injector resistance
With the connector off, measure across the injector pins and compare with a neighboring cylinder. Typical port injectors read roughly 11–16 Ω (your spec may differ); a big mismatch or infinite reading condemns the injector.
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4 Verify supply voltage
Key on, check for battery voltage on the injector’s feed wire. Missing voltage means fuse, relay, or harness — not the injector.
-
5 Swap-test if accessible
On engines where access allows, swap the suspect injector with another cylinder. If the code follows the injector, replace it; if it stays, repair the wiring.
Parts & tools you may need
- OBD-II scanner (code reader with freeze frame / live data)
- Digital multimeter
- Electrical contact cleaner
- Replacement fuel injector (if resistance test fails)
- Injector seal/O-ring kit (always replace when an injector comes out)
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Related codes
Frequently asked questions
- Will an injector cleaner fix P0207?
- No. Cleaners address flow restrictions; this code reports an electrical fault. No additive repairs a broken wire or a shorted solenoid.
- Can I drive with P0207?
- If the injector truly isn’t firing, that cylinder is dead — you’ll feel the shake, waste fuel, and stress the catalytic converter. Treat it like an active misfire: minimal, gentle driving only.
- How do I know if it’s the injector or the wiring?
- Resistance at the injector pins tests the injector; voltage at the connector tests the supply side. Between those two five-minute measurements, the answer is on your multimeter.
- Why do several injector codes appear together?
- Shared cause: a blown fuse, a failing relay, or harness damage where the injector wires run together. Individual injectors rarely fail simultaneously.