P06B2

Code

Generic P — Powertrain

Sensor Power Supply A Circuit High

Brand: Generic

Type: P — Powertrain

Views: UK: 24 EN: 28 RU: 27

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Page language: EN

Causes

Short to battery/ignition voltage on sensor supply wiring
Failed sensor that is backfeeding the supply
Faulty PCM voltage reference/regulator or internal short
Corroded/damaged connector or harness allowing unintended voltage
Aftermarket equipment or incorrect wiring modification

Symptoms

Malfunction Indicator Lamp (MIL) illuminated
Stored and repeatable DTC P06B2 (may be current or pending)
Possible multiple sensor/performance related codes if several sensors use the same reference
Engine may run normally or show drivability issues depending on affected sensors
Intermittent faults that appear under certain conditions (vibration, moisture)

What to check

Retrieve freeze-frame and freeze data; note conditions when code set (ignition on/off, engine running, temperature, load)
Visual inspection of wiring harnesses and connectors for damage, corrosion, water intrusion or recent repairs
Back-probe the sensor power supply pin(s) with key ON, engine OFF and measure voltage
Compare supply voltage at the PCM connector to the sensor connector(s) to locate where the high voltage appears
Disconnect the suspect sensor(s) and see if the code clears or the supply voltage returns to normal
Wiggle test harness while observing voltage / DTC response to find intermittent shorts

Signal parameters

Nominal sensor reference/supply voltage: approximately 5.0 V (typical)
High threshold: usually greater than ~5.5–6.0 V (depends on manufacturer)
Battery voltage: ~12–14.5 V — a true short to B+ will show near battery voltage on the reference line
DTC set logic: controller detects supply voltage above expected threshold for a defined time or number of cycles

Diagnostic algorithm

Confirm the code with an OBD-II scanner and record freeze-frame/DT data
Perform a visual inspection of related wiring, connectors and sensors for damage or corrosion
With ignition ON (engine OFF) back-probe the sensor reference/power pin and measure voltage; note if it is near battery voltage
If supply is high, unplug the sensor(s) supplied by Sensor Power Supply A and re-measure the supply voltage at the harness connector
If voltage returns to normal with the sensor disconnected, suspect the sensor (or shorted sensor harness) — replace or test sensor per OEM procedure
If voltage remains high with sensors disconnected, trace wiring toward PCM looking for pin-to-power short (inspect splices, junctions, accessory taps)
Perform resistance checks to battery positive and ground (with power off) from the reference wire to locate a short or leakage path
Inspect and, if needed, disconnect aftermarket accessories that may be tied into the reference circuit
If wiring and connectors are good and short to B+ cannot be found, evaluate/replace PCM only after confirming failure with a known-good PCM or professional bench test

Likely causes

Wire or pin shorted to B+ at a harness splice, connector or nearby power source
Defective sensor feeding battery voltage back into the reference circuit
Damaged insulation with intermittent contact to a hot circuit
PCM internal regulator or driver failure (less common)
Contaminated connector (water/corrosion) causing resistance changes or leakage paths

Fault status

⚠️ Status

PCM detected voltage above expected range on Sensor Power Supply A circuit; code set when measured or internally monitored supply exceeds predefined threshold.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 1.0-2.5 hours

Repair manuals