P06A7
Reference Voltage B Circuit Range/PerformanceP06A7 is a generic OBD-II powertrain diagnostic trouble code: Reference Voltage B Circuit Range/Performance. 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 P06A7 means
P06A7 is a generic powertrain code indicating the powertrain control module has detected that the reference voltage on the sensor reference B circuit is out of range or performing abnormally. The PCM provides one or more regulated reference voltages, typically 5 volts, to power its analog sensors. The B designation identifies a second, separate reference circuit that feeds its own group of sensors, kept apart from the A reference so a fault on one circuit does not take down every sensor.
When the PCM measures a reference B voltage that is too high, too low, or fluctuating outside the calibrated window (commonly expected around 5 volts for these circuits), it stores P06A7 and generally illuminates the malfunction indicator lamp. Because the sensors sharing this reference all depend on a stable feed, a single circuit fault can cause several of them to report implausible values, so P06A7 is often accompanied by other sensor range or performance codes.
The most likely causes are a short to ground, a short to voltage, an open in the reference wire, a corroded connector, or a shorted sensor loading the reference bus. Diagnosis should start with reading all codes and inspecting the reference B wiring and connectors, then measuring the reference voltage at the affected sensors. Disconnecting sensors individually can isolate a shorted unit before the PCM is considered.
Common causes
Most-frequently reported root causes when P06A7 is logged.
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1
Short to ground on the sensor reference B circuit.
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2
Short to battery voltage on the reference B circuit.
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3
Open or high-resistance in the reference B wire.
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4
A shorted or failed sensor loading down the shared reference.
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5
Corroded, damaged, or loose connectors on the reference B circuit.
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6
Chafed or pinched wiring harness causing intermittent faults.
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7
Faulty PCM reference voltage supply for circuit B (only after wiring is cleared).
Symptoms drivers notice
How to diagnose P06A7
A typical diagnostic flow when this code is present.
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1
Retrieve all stored DTCs and freeze frame data with a scan tool, noting which sensors share the reference B circuit.
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2
Inspect the reference B wiring and connectors for corrosion, chafing, or loose terminals.
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3
Measure the reference voltage at the affected sensor connectors and compare to the expected value.
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4
Test the reference B circuit for shorts to ground or voltage and for continuity to the PCM.
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5
Disconnect the sensors on reference B one at a time to determine whether the voltage recovers, isolating a shorted sensor.
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6
Repair the faulty wire, connector, or sensor found during testing.
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7
Clear the codes and confirm the reference voltage stays stable during a road test.
Related powertrain codes
- P0600 — Serial Communication Link Malfunction
- P0601 — Internal Control Module Memory Check Sum Error
- P0602 — Control Module Programming Error
- P0603 — Internal Control Module Keep Alive Memory (KAM) Error
- P0604 — Internal Control Module Random Access Memory (RAM) Error
- P0605 — Internal Control Module Read Only Memory (ROM) Error
Frequently asked questions
How is reference B different from reference A?
They are separate regulated reference circuits from the PCM, each feeding its own group of sensors, so a fault on the B circuit affects only the sensors on that feed.
What voltage should the reference B circuit show?
These reference circuits are typically around 5 volts; a reading well above or below that, or one that fluctuates, sets the code.
Can P06A7 be caused by a single sensor?
Yes, a sensor that has shorted internally can pull the shared reference out of range, so sensors are disconnected individually to find the offending unit.
Is P06A7 an ECM failure?
Rarely; the great majority of cases are wiring shorts or opens, connector problems, or a shorted sensor, and the PCM is only suspected after those are eliminated.
Disabling P06A7 in software
RaceTune can permanently disable P06A7 — 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.
ECU families we can disable P06A7 on
We hold the DaVinci A2L disable definitions for these families, so the exact P06A7 path and mask addresses are mapped. verified marks a confirmed disable definition. We support many more — upload your file and our identifier will match it automatically.
- Bosch EDC17C66 verified
- Bosch EDC17CP57 verified
- Bosch MG1CP002 verified
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.
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