P2145 – Exhaust Gas Recirculation Vent Control Circuit High

P2145 is a Powertrain Diagnostic Trouble Code that points to an abnormal electrical condition in a fuel injector control circuit as monitored by the engine controller. Under SAE J2012 structure, “P” indicates powertrain and the numeric range commonly relates to fuel/air metering and injector control monitoring, but the exact cylinder or injector identification can vary by make, model, and year. To avoid guessing, you confirm the affected circuit by reading scan-tool data and then validating power, ground, and control-signal integrity with basic electrical testing.

What Does P2145 Mean?

SAE J2012 defines the DTC format and how codes are categorized, and standardized DTC descriptions are published in the SAE J2012-DA digital annex. In practice, many P-codes have a fairly consistent system-level meaning, but the exact affected injector/cylinder or driver strategy can still vary by vehicle, so you should confirm the application-specific definition in service information and with scan-tool data.

P2145 is shown here without a hyphen suffix, meaning it is presented without a Failure Type Byte (FTB). If an FTB were present (for example, a “-xx” suffix), it would identify a subtype such as the specific electrical failure behavior or detection method. What makes P2145 distinct is that it is a control-circuit signal behavior problem the controller considers implausible for normal injector operation, not simply a general “something is wrong” warning.

Quick Reference

• System: Powertrain (fuel injector control monitoring)
• What it indicates: Abnormal injector control circuit signal behavior detected by the Engine Control Module (ECM) or Powertrain Control Module (PCM)
• What varies by vehicle: Which injector/cylinder is associated, driver type (high-side/low-side), and the exact electrical thresholds
• Commonly involved areas: Injector connector pins, harness routing near hot/abrasion points, shared power feed, and controller driver circuitry
• Best first checks: Freeze-frame data, visual harness inspection, injector resistance/inductance comparison, and control-signal verification with a lab scope
• Risk level: Moderate to high (misfire, catalyst damage risk, stalling possible depending on severity)

Real-World Example / Field Notes

In the bay, P2145 often shows up after recent engine work or on vehicles with brittle under-hood wiring: you’ll see the harness pulled tight across a bracket or resting on a hot component, and the injector control wire insulation gets chafed. One possible cause I’ve confirmed is a spread or corroded terminal at an injector connector that passes a quick visual check but fails a wiggle test while watching misfire counters and injector pulse on a scope. Another commonly associated scenario is a shared injector power feed with higher-than-normal voltage drop under load; the engine may idle “okay” but stumble on acceleration when current demand rises.

Symptoms of P2145

• Check Engine Light: The Malfunction Indicator Lamp (MIL) is on, often after a cold start or a heavy-load event when injector control activity is high.
• Rough idle: You may feel shaking or unstable idle speed if injector control is being limited or if fueling becomes uneven.
• Misfire-like hesitation: Stumble on tip-in acceleration can occur when commanded fueling and actual engine response don’t agree.
• Reduced power: The Powertrain Control Module (PCM) may enter a protective strategy that limits torque to prevent catalyst or engine damage.
• Hard starting: Longer crank time can happen if injector control is inhibited, delayed, or inconsistent during cranking.
• Poor fuel economy: If fueling control is degraded (even intermittently), you can see noticeably worse miles per gallon.
• Fuel odor or rich/lean behavior: Exhaust smell, surging, or unstable air-fuel behavior may show up when injector control signals aren’t behaving plausibly.

Common Causes of P2145

Most Common Causes

• Harness or connector issue in the fuel injector control circuit (rubbed-through insulation, fretting, moisture intrusion, loose terminal tension) causing an implausible signal behavior
• Poor power or ground integrity affecting injector operation (voltage drop under load, ground offset, intermittent open at a splice)
• Injector-related electrical issue (for example, abnormal coil resistance or internal intermittency) that makes the control signal/current behavior fail plausibility checks
• Aftermarket wiring changes (remote start, alarm, injector/engine harness repairs) disturbing circuit integrity or shielding

Less Common Causes

• Connector or terminal damage at the PCM affecting the injector driver/control signal path (only after confirming external wiring and loads)
• Electromagnetic interference or routing problems near ignition components or high-current wiring leading to noisy injector control signals
• Fuel injector driver strategy being limited due to another underlying mechanical condition that causes repeated plausibility failures (confirm with engine condition checks, not assumptions)
• Possible internal processing or input/output stage issue in the PCM, considered only after the circuit, power, ground, and load tests prove good

Diagnosis: Step-by-Step Guide

Tools you’ll want: a scan tool with live data and Mode $06 capability, a digital multimeter (DMM), a lab scope (2-channel preferred), a fused test light, back-probing pins, wiring diagrams/service information, a battery charger or maintainer, and basic hand tools for connector inspection.

1. Verify the complaint and capture freeze-frame data (RPM, load, coolant temp, battery voltage). Clear the code and perform a short drive or run condition to see if it resets consistently.
2. Check battery and charging health first. Measure key-off voltage and running voltage, then do a loaded voltage-drop test on main grounds. Low system voltage can skew injector control plausibility.
3. Perform a visual inspection of the injector harness and connectors. Look for oil saturation, melted loom, chafing on brackets, and pin fit issues. Wiggle-test while monitoring misfire counters/fuel trims and injector-related PIDs.
4. Using wiring diagrams, identify the injector control circuit(s) involved for your vehicle. Because definitions and monitored circuits can vary by make/model/year, confirm which injector driver or bank the PCM is flagging using scan tool data and service info.
5. Key off, disconnect the injector(s) in the suspect circuit and measure injector coil resistance. Compare to service specifications and to other injectors. A coil that’s out of family can trigger implausible control behavior.
6. Check the circuit for shorts to ground and shorts to power with the DMM (injector disconnected, PCM connector disconnected if needed). Measure resistance to ground and to battery positive; anything unexpectedly low demands harness isolation.
7. Verify power feed integrity to the injector(s) with a fused test light or DMM under load. A circuit can show voltage with no load but collapse when current is demanded.
8. Use a lab scope to observe injector control signal quality during the condition that sets the code. Look for abnormal dwell, missing events, excessive noise, or patterns that don’t match other cylinders/commands.
9. If wiring and injector tests pass, perform a pin-to-pin continuity and loaded voltage-drop test end-to-end on the control circuit while flexing the harness. Intermittents often only show up under movement and heat.
10. Only after all external tests pass, consider PCM-side issues: confirm PCM powers/grounds are clean (voltage drop under load), then evaluate whether the driver output behavior is inconsistent with commanded operation.

Professional tip: Don’t rely on static resistance checks alone—an injector or wire can test “good” cold and fail hot. Heat-soak the engine or use a heat gun carefully on the harness/injector area while watching the injector waveform and voltage-drop readings to catch intermittents that trigger P2145.

Possible Fixes & Repair Costs

Repair cost depends on what your tests prove about the fuel injector control circuit and its ability to carry current and produce a plausible switching signal. Typical ranges (parts and labor) are: low $0–$120 (clean/secure connectors, repair a rubbed harness section, replace a blown fuse found during cause testing), typical $180–$650 (repair wiring with proper splices, replace an injector only after resistance/current or balance testing shows it’s out of spec, or replace a relay where voltage drop/load testing fails), and high $700–$1,800+ (extensive harness repair, or addressing a possible internal processing or input-stage issue in the Powertrain Control Module (PCM) only after power, ground, and external signal tests pass).

Justified fixes should match your findings: repair wiring if you measured excessive voltage drop or intermittent continuity while wiggling the harness; replace an injector if its resistance, current ramp, or balance contribution is inconsistent with the others; address power feed/ground issues if the injector supply is missing or collapses under load; consider PCM involvement only if the driver command and circuit integrity are proven good but the control output remains implausible.

Can I Still Drive With P2145?

Sometimes you can, but you shouldn’t assume it’s safe. P2145 points to an injector control circuit plausibility problem, which can cause misfire, rough running, poor throttle response, or stalling depending on how the PCM reacts. If the engine is shaking, flashing a malfunction indicator lamp, or lacks power, reduce load and avoid driving. If it seems normal, you may be able to drive gently to a shop, but avoid towing, steep grades, and high RPM until you verify the circuit.

What Happens If You Ignore P2145?

Ignoring P2145 can turn an intermittent circuit issue into a repeat stall/no-start, and persistent misfire can overheat the catalytic converter, increase fuel consumption, and wash down cylinder walls. A marginal connection can also arc and damage terminals, making the eventual repair more expensive and less reliable.

Last updated: February 13, 2026

Vehicles Commonly Affected by P2145

P2145 is commonly seen across many makes because injector control circuits are universal to modern engine management and are sensitive to voltage drop and connection quality. It’s often reported on vehicles from Ford, Volkswagen/Audi, and GM, as well as turbocharged or direct-injection applications where injector current control is tightly monitored. The more complex the under-hood wiring, heat exposure, and vibration environment, the more likely small harness or terminal issues can trigger plausibility faults.