P2AE0
Reductant Injection Control Circuit HighP2AE0 is a generic OBD-II powertrain diagnostic trouble code: Reductant Injection Control Circuit High. It is logged by the engine control unit when the powertrain monitor detects that a specific fault threshold has been exceeded — typically resulting in the malfunction-indicator lamp (MIL / check-engine light) being illuminated.
What P2AE0 means
P2AE0 is stored when the ECM detects a higher-than-expected voltage or current on the control circuit of the DEF (reductant) injection valve. The dosing injector is the component that sprays a precisely metered quantity of DEF into the exhaust stream upstream of the SCR catalyst. The ECM drives this injector via a dedicated output driver, and the feedback from that driver is monitored for circuit integrity.
A high-circuit condition on the injector control circuit typically indicates a short of the control signal wire to a voltage source, an internal ECM driver fault producing an out-of-range output, or an injector coil that has developed an internal fault causing excessive back-EMF or resistive behavior that raises the monitored circuit voltage above its expected range. If the ECM detects this condition, it may disable the injector output to protect the driver stage, halting DEF injection entirely.
With DEF injection disabled, the SCR catalyst will cease to convert NOx and the vehicle will likely set a companion SCR efficiency code within one or two drive cycles. Depending on the manufacturer's inducement calibration, a power reduction derate may follow after a defined number of failed operation cycles. Prompt repair is important to avoid both emissions non-compliance and potential inducement penalties.
Common causes
Most-frequently reported root causes when P2AE0 is logged.
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1
Dosing injector control wire shorted to battery positive or ignition supply voltage.
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2
Failed ECM internal driver for the dosing injector output.
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3
Dosing injector coil internal fault causing abnormal electrical behavior on the control circuit.
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4
Wiring harness damage allowing injector signal wire to contact a powered circuit.
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5
Corroded connector creating a resistive bridge between the injector control pin and a supply pin.
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6
Aftermarket or incorrect replacement injector with incompatible coil impedance.
Symptoms drivers notice
How to diagnose P2AE0
A typical diagnostic flow when this code is present.
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1
Read all DTCs; confirm P2AE0 and note any companion SCR efficiency or NOx codes.
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2
Inspect the dosing injector connector and wiring harness for visible damage, heat degradation, or shorts.
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3
Disconnect the injector and measure the control circuit voltage on the harness side; an elevated voltage confirms a short to supply.
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4
Measure injector coil resistance at the injector pins; compare to the vehicle service specification for the injector type.
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5
With injector disconnected and key on, command the injector active via the scan tool and verify the ECM output behaves correctly.
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6
If the harness is intact and injector resistance is correct, suspect an ECM driver fault.
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7
Repair wiring or replace the injector as indicated; retest after clearing codes.
Vehicles where we've handled P2AE0
Platforms in our catalogue with confirmed P2AE0 coverage.
Related powertrain codes
- P2A00 — O2 Sensor Circuit Range/Performance, Bank 1 Sensor 1
- P2A01 — O2 Sensor Circuit Range/Performance - Bank 2 Sensor 1
- P2A02 — Sensor Circuit Range/Performance Bank 1 Sensor 3
- P2A03 — Sensor Circuit Range/Performance Bank 2 Sensor 1
- P2A04 — Sensor Circuit Range/Performance Bank 2 Sensor 2
- P2A05 — Sensor Circuit Range/Performance Bank 2 Sensor 3
Frequently asked questions
Will the vehicle derate immediately when P2AE0 sets?
Not necessarily immediately, but if dosing is disabled the SCR efficiency monitor will fail within a drive cycle or two, and manufacturer-specific inducement timers will begin counting toward a power reduction.
How do I know if the ECM driver itself is faulty versus the wiring?
Disconnect the injector and test for abnormal voltage or resistance on the harness-side connector. If the fault clears when the injector is disconnected and reappears only when connected, the injector or its wiring is more likely at fault than the ECM.
Can P2AE0 be caused by DEF freezing in the injector?
Frozen DEF can block the injector nozzle and may cause abnormal back-pressure, but a frozen nozzle is more likely to produce a dosing pressure fault rather than a control circuit high code.
Is the dosing injector the same as the DEF pump?
No. The pump pressurizes the DEF supply line from the tank, while the dosing injector is a separate solenoid valve that meters the actual spray into the exhaust. Both have distinct fault codes.
Disabling P2AE0 in software
RaceTune can permanently disable P2AE0 — and any other OBD-II diagnostic trouble code — on every ECU family we support. The monitor is disabled inside the ECU itself, so the fault stops being logged: the warning light stays off and the engine never enters limp mode for this code. The change is tied to your exact software version.
ECUs with a P2AE0 disable in our catalogue
Confirmed coverage from our recipe database — we support many more families. Upload your file and our identifier will match it automatically.
- Bosch EDC17C50 verified 1 software version
Software modifications affect emissions compliance and are not road-legal in many jurisdictions. RaceTune service files are intended for motorsport, off-road, and export use.
Got P2AE0 in your scan?
Upload your ECU file — we'll identify the exact software version and confirm whether a disable is available for your car.
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