HomeTrouble CodesP2699

P2699 — Exhaust Aftertreatment Fuel Injector Circuit Low

Manufacturer-specificPowertrain (engine & transmission)

P2699 signals a low voltage condition in the exhaust aftertreatment fuel injector control circuit, meaning the injector is not receiving sufficient current. This can affect emissions control and engine performance. The code is logged when the PCM detects that the injector's electrical circuit is not operating within expected parameters.

Symptoms

What causes it — most likely first

1. Failed exhaust aftertreatment fuel injector

The injector may be internally shorted or have a bad coil, causing insufficient current draw.

2. Wiring or connector fault

Damaged, corroded, or loose wires and connectors in the injector circuit can reduce voltage.

3. Blown fuse or power supply issue

A blown fuse or failed relay can cut power to the injector circuit, triggering low‑circuit detection.

4. Corroded injector harness terminal

Oxidation at the terminal can increase resistance and mimic a low circuit condition.

5. Faulty PCM injector driver

The PCM's output circuit can fail, but this is uncommon and usually follows other electrical checks.

How it's diagnosed

  1. Inspect the injector wiring harness and connectors for damage, corrosion, or looseness.
  2. Measure injector resistance and compare it to the manufacturer's specifications.
  3. Check for voltage at the injector connector with the ignition turned on.
  4. Verify that the associated fuse and relay are intact and receiving power.
  5. Scan for additional related codes and monitor live data for injector performance.
  6. Replace the faulty injector or repair any damaged wiring/connector as needed.

Code facts & related codes

SystemPowertrain (engine & transmission)
StandardizationManufacturer-specific (P1/B1/C1/U1)

Frequently asked

Can a bad PCM cause P2699?

It is possible but rare; most often the issue is the injector, wiring, or a blown fuse rather than the PCM.

Do I need to replace the entire exhaust aftertreatment system?

No, usually only the faulty injector or wiring needs repair; the rest of the system typically remains functional.

Will this code clear itself if the problem is intermittent?

It may clear if the fault does not recur, but the underlying issue should be addressed to prevent re‑occurrence.

Is this code related to emissions compliance?

Yes, it pertains to the aftertreatment fuel injection used to manage emissions.