P2907 – Exhaust Aftertreatment Fuel Injector Circuit/Open

System: Powertrain | Standard: ISO/SAE Controlled | Fault type: Circuit/Open

Definition source: SAE J2012/J2012DA (industry standard)

P2907 indicates the powertrain control system detected an open circuit condition in the exhaust aftertreatment fuel injector circuit. This injector is used as part of the exhaust aftertreatment strategy, and the module monitors the electrical circuit to confirm it can command the injector and “see” the expected electrical response. An open can be caused by anything from an unplugged connector to a broken wire or internal injector electrical failure. Exact component location, wiring layout, and monitor behavior vary by vehicle, so confirm circuit IDs, connector pinouts, and test specifications using the correct service information before making repairs.

What Does P2907 Mean?

P2907 – Exhaust Aftertreatment Fuel Injector Circuit/Open means the control module has determined the electrical circuit for the exhaust aftertreatment fuel injector is open (not electrically continuous) when it expects the circuit to be intact. Under SAE J2012 DTC structure, the code identifies a standardized powertrain fault entry, while the description defines the fault type as Circuit/Open. This points you toward electrical integrity issues—such as an unplugged connector, damaged wiring, poor terminal fit, or an open internal winding—rather than a calibration or “performance” concern.

Quick Reference

• Subsystem: Exhaust aftertreatment fuel injector electrical circuit (actuator, wiring, connectors, power/ground paths, and driver control).
• Common triggers: Disconnected injector connector, broken conductor, backed-out terminal, corrosion causing loss of continuity, or an open injector coil.
• Likely root-cause buckets: Wiring/connector faults; injector electrical open; power feed or ground path open; driver circuit or module fault (less common); harness damage near heat/vibration points.
• Severity: Typically moderate—may lead to aftertreatment inefficiency and reduced-power strategies; usually not an immediate safety issue unless other warnings are present.
• First checks: Verify connector fully seated; inspect harness routing/heat damage; check for obvious pin damage; confirm fuses/relays supplying the circuit (varies by vehicle).
• Common mistakes: Replacing the injector without proving an open in the injector or harness; overlooking poor terminal tension; ignoring related power/ground opens upstream.

Theory of Operation

The exhaust aftertreatment fuel injector is an electrically controlled actuator used to add fuel in the exhaust stream as part of the aftertreatment strategy. The control module commands the injector on and off through a dedicated driver circuit while the injector receives power and ground through the vehicle’s wiring (the exact arrangement varies by vehicle). For the injector to operate, the circuit must be electrically continuous from the module through the harness and injector and back through the return path.

To detect a Circuit/Open fault, the module monitors circuit integrity during command events and/or self-checks. If the circuit is open—due to an unplugged connector, broken wire, poor terminal contact, or an open injector winding—the module cannot achieve the expected electrical response and sets P2907. Because designs differ, use service information to identify which side is switched, which pins are involved, and the correct testing method.

Symptoms

• Warning light: Check engine light illuminated, sometimes after an aftertreatment-related monitor runs.
• Reduced power: Limited torque or engine power due to protective aftertreatment strategies (varies by vehicle).
• Aftertreatment message: Driver information message related to emissions/aftertreatment operation (if equipped).
• Regeneration issues: Delayed, interrupted, or inhibited aftertreatment events due to inability to dose fuel.
• Increased smoke/odor: Changes in exhaust odor or visible exhaust under certain conditions (vehicle- and strategy-dependent).
• Poor fuel economy: Efficiency reduction if the system compensates or repeats attempts (varies by vehicle).
• Additional DTCs: Companion codes for aftertreatment control, dosing control, or related circuit faults may also be present.

Common Causes

• Exhaust aftertreatment fuel injector connector unplugged, not fully seated, or incorrectly latched
• Open circuit in the injector control wire between the injector and the control module (broken conductor, cut harness)
• Open in the injector power/feed circuit (if the design uses a dedicated feed) due to a blown fuse, failed relay, or open splice (varies by vehicle)
• Poor terminal fit, backed-out pin, corrosion, or moisture intrusion causing loss of continuity at the injector or intermediate connectors
• Harness damage near hot or moving components leading to intermittent open (chafing through to an internal break)
• Internal open in the exhaust aftertreatment fuel injector (open coil/winding or internal connection failure)
• Open or high-resistance ground path affecting the injector circuit (where the design uses a serviceable ground point)
• Control module driver/circuit fault (less common; consider after wiring and injector integrity are verified)

Diagnosis Steps

Basic tools include a scan tool with data logging, a digital multimeter, and vehicle-specific wiring diagrams/service information. Helpful additions are back-probing pins, terminal inspection tools, and a test light approved for low-current circuits (as applicable). For intermittent opens, plan to do a wiggle test and capture a live-data log while reproducing the fault.

1. Confirm the code and context. Scan for DTCs and record freeze-frame and any aftertreatment-related data available. Note whether P2907 is current/active or stored/history, and check for companion power supply or communication codes that could affect testing.
2. Clear and re-check. Clear DTCs and run the applicable monitor/drive cycle per service information (varies by vehicle). If P2907 resets quickly, treat it as an active electrical open and prioritize circuit integrity checks.
3. Locate the exhaust aftertreatment fuel injector and its harness routing. Using service information, identify connector views, pin functions, and any inline connectors/splices/fuses/relays associated with the injector circuit. Visually trace the harness for heat damage, abrasion points, and signs of prior repairs.
4. Perform a focused connector inspection. Key off. Disconnect the injector connector and any accessible intermediate connector(s). Inspect for bent pins, spread terminals, corrosion, moisture, poor pin retention, and backed-out terminals. Repair terminal issues before continuing; a poor pin fit can mimic an open circuit.
5. Wiggle test while monitoring data. Reconnect components. With the scan tool monitoring relevant PIDs (and/or the DTC status), gently wiggle the injector connector and harness at known stress points (near the injector, along brackets, and at pass-throughs). If the fault status changes, isolate the exact section that triggers the open.
6. Check the injector for an internal open. With the injector disconnected, measure injector resistance/continuity at the injector terminals and compare only to the manufacturer specification (no universal value). If the reading indicates an open or unstable connection when lightly moving the connector body, suspect the injector or its connector terminals.
7. Check circuit continuity end-to-end. Key off and follow service information to test continuity of the injector control wire(s) between the injector connector and the module-side connector or an intermediate connector. An open reading indicates a broken conductor, failed splice, or connector issue. If continuity is present, flex the harness during the test to expose intermittent opens.
8. Verify power/feed integrity (if applicable). If the design provides a separate power/feed to the injector, verify that the feed is present at the injector connector under the correct conditions per service information. If power is missing, trace upstream through the fuse/relay/splice points. Do not assume the injector is bad until feed integrity is verified.
9. Voltage-drop test loaded paths. When the circuit can be commanded on (service function varies by vehicle), perform voltage-drop testing across suspect connections (connector to connector, ground points, and splices) while the circuit is loaded. Excessive drop indicates high resistance that can present as an effective open to the control module.
10. Evaluate module-side driver only after wiring/injector checks pass. If the injector, connectors, feed/ground (as applicable), and wiring continuity/load testing are all verified good, consult service information for module driver tests and connector pin checks. Confirm there is no terminal damage at the module connector before considering module repair/replacement.

Professional tip: If P2907 is intermittent, prioritize a harness-flex continuity check and a live-data log during the exact conditions when the code sets. Opens often occur at strain relief points (connector backshells, tight bends, and clipped sections). Fixing terminal tension or a partially broken conductor can resolve the issue without replacing the injector or control module.

Possible Fixes & Repair Costs

Repair cost for P2907 varies widely because the underlying issue can be as simple as a loose connector or as involved as harness repair or component replacement, and labor time depends on access, required testing, and confirmation procedures.

• Repair or replace damaged wiring in the exhaust aftertreatment fuel injector circuit (open wire, chafed section, broken conductor)
• Clean, reseat, and secure electrical connectors; correct poor terminal tension or pin fit that creates an open-circuit condition
• Repair verified power feed or ground path issues affecting the injector circuit (including restoring continuity and fixing corrosion at splices)
• Replace the exhaust aftertreatment fuel injector only after testing confirms the injector coil/circuit is open or out of specification per service information
• Repair or replace related harness sections or inline connectors where continuity loss is found during wiggle testing
• Perform control module output-circuit verification and follow service information if module-side driver faults are confirmed

Can I Still Drive With P2907?

You can sometimes drive with P2907, but it is not recommended to ignore it because the exhaust aftertreatment fuel injector may not operate as intended, which can lead to reduced emissions control performance and possible derate or limited-power strategies depending on the vehicle. If you experience reduced power, severe drivability changes, warning messages indicating limited operation, or any safety-related symptoms (stalling, no-start, brake/steering warnings), do not continue driving—have the vehicle inspected and repaired.

What Happens If You Ignore P2907?

If P2907 is ignored, the open circuit condition may persist or worsen, potentially causing repeated warning lights, aftertreatment performance issues, and the possibility of the system disabling dosing functions. Over time this can contribute to further faults, drivability limitations, failed inspections where applicable, and increased repair complexity if wiring damage spreads or connectors deteriorate further.

Related Codes

• P2906 – Exhaust Aftertreatment Fuel System Performance
• P2905 – Airflow Too High
• P2904 – Airflow Too Low
• P2903 – Diesel Particulate Filter Regeneration – Too Frequent
• P2902 – Diesel Particulate Filter Regeneration – Not Completed
• P2901 – Diesel Particulate Filter Regeneration – Aborted
• P2900 – Fuel Rail System Performance
• P2941 – Airflow Sensor “C” Circuit
• P2940 – Airflow Sensor “B” Circuit Intermittent/Erratic
• P2939 – Airflow Sensor “B” Circuit High

Key Takeaways

• P2907 indicates an electrical circuit/open condition in the exhaust aftertreatment fuel injector circuit, not a confirmed mechanical failure.
• Most confirmed causes are in wiring, connectors, terminals, splices, or grounds; verify continuity and pin fit before replacing parts.
• Diagnosis should be test-driven: continuity checks, voltage-drop testing under load, and wiggle testing to locate opens.
• Vehicle behavior can vary; follow service information for connector views, circuit routing, and confirmation steps.
• Driving may be possible, but prolonged operation can lead to derate/limited power and additional aftertreatment-related faults.

Vehicles Commonly Affected by P2907

• Vehicles equipped with an exhaust aftertreatment fuel injector used to support aftertreatment operation
• Applications that use a dedicated dosing injector in the exhaust system controlled by the powertrain controller
• Vehicles operated in environments that accelerate connector corrosion (road salt, high humidity, frequent temperature cycling)
• High-mileage vehicles where harness flexing and heat exposure can fatigue conductors and terminal tension
• Vehicles with prior exhaust or aftertreatment service where connectors may be left loose or wiring may be pinched
• Vehicles used in severe duty cycles (extended idling, stop-and-go, heavy load) that increase thermal stress near the exhaust
• Vehicles with underbody impacts or debris exposure that can damage harness routing to exhaust-mounted components
• Vehicles that have had aftermarket electrical modifications near underbody harnesses (routing and splices vary by vehicle)

FAQ

Does P2907 mean the exhaust aftertreatment fuel injector is bad?

No. P2907 indicates the control module detected a circuit/open condition in the exhaust aftertreatment fuel injector circuit. The injector could be faulty, but an open is often caused by wiring damage, connector/terminal issues, or a broken splice. Testing is required to confirm the root cause.

What is the most common reason for a circuit/open fault on this circuit?

The most common causes are connector-related issues (unplugged connector, poor terminal tension, corrosion) and harness damage (broken conductor, chafing near brackets, heat damage near the exhaust). These create a loss of continuity that the module interprets as an open circuit.

Can a blown fuse cause P2907?

It can, depending on how the circuit is designed. If the injector’s power supply is protected by a fuse and that fuse opens, the module may detect a loss of current flow consistent with a circuit/open condition. Use service information to identify the correct fuse and verify why it opened before replacing it.

Will clearing the code fix P2907?

Clearing the code only removes the stored fault from memory; it does not restore electrical continuity. If the open circuit remains, P2907 will typically return after the next monitor run or command of the exhaust aftertreatment fuel injector. Clear codes only after repairs and verification testing.

What tests best confirm an open circuit for P2907?

The most direct confirmation is a continuity test of the injector circuit (with power safely off), followed by voltage-drop testing under load where applicable, and a wiggle test while monitoring the circuit status or commanded operation. Always use service information for connector pinouts and test conditions.

For an accurate repair plan, confirm the open by testing from the control module connector to the injector connector and inspecting intermediate splices or inline connectors, since the fault can be anywhere along the circuit.