P06A7

Code

LAND ROVER P — Powertrain

Reference voltage of sensor B - Circuit range/performance

Brand: LAND ROVER

Type: P — Powertrain

Views: UK: 21 EN: 41 RU: 26

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Page language: EN

Causes

Open, short to ground, or short to battery in the reference supply or sensor signal wiring
Corroded, loose or damaged connector at sensor B
Defective sensor (internal short/open)
Failed or intermittent ECM reference/regulator circuit
Low or unstable battery/charging voltage affecting reference
Aftermarket modification or repair damage to the harness

Symptoms

Malfunction Indicator Lamp (MIL) / Check Engine light on
Reduced engine performance or limp mode (depending on sensor function)
Irregular idle, stalling, or rough running
Poor fuel economy or drivability issues
Intermittent faults that may come and go with vibration or temperature

What to check

Read stored codes and freeze-frame / live-data with a scan tool to capture conditions when the code set
Identify exact sensor B location and pinout from factory service information
Visually inspect sensor connector and wiring for damage, corrosion, water, or open pins
Backprobe the sensor connector (key ON, engine OFF) and measure reference voltage with a DMM
Check battery voltage and charging system for stability
Wiggle test harness while monitoring live-data or reference voltage for intermittent faults

Signal parameters

Expected sensor reference voltage: typically ~5.0 V (common tolerance ±0.25 V) with key ON, engine OFF
Reference must be stable (little ripple or noise) and not drop with load or vibration
Sensor output (if present) will vary according to sensed parameter; if reference is absent, output cannot be trusted
Battery voltage should be within normal range (approx. 12–14.5 V) during tests

Diagnostic algorithm

Retrieve DTCs and freeze-frame data. Note conditions (engine temp, rpm, battery voltage) when code set.
Consult OEM wiring diagrams/service manual to confirm sensor B function, connector pinout, and which ECM pin provides the reference.
Perform visual inspection of the sensor, connector, and harness for damage, corrosion, water, or repair splice points.
With key ON (engine OFF), backprobe the sensor connector and measure the reference voltage at the ECM side and the sensor side; compare readings.
If reference voltage is missing at the sensor connector but present at ECM pin, inspect/repair harness between ECM and sensor for open circuit or high resistance.
If reference is missing at ECM pin, check related fuses, main power/ground connections and test ECM reference/regulator circuit per factory procedure.
If reference is present but unstable/noisy, use an oscilloscope to look for noise, intermittent dropouts, or spikes. Wiggle the wiring harness while monitoring.
Unplug the sensor and measure connector pins for short to ground or short to battery (check resistance to ground/battery).
If wiring and reference appear good, substitute a known-good sensor or bench-test the sensor if possible to confirm sensor fault.
Repair or replace damaged wiring/connectors or replace faulty sensor/ECM as indicated. Clear codes and perform test drive to confirm repair.
If ECM replacement is considered, confirm wiring and grounds are correct and perform OEM-specific ECM programming and relearn procedures.

Likely causes

Damaged wiring between ECM and sensor B (chafing, pinched, broken)
Poor pin contact or water ingress at the sensor connector
Sensor internal electrical failure
ECM reference-voltage output fault
Blown fuse or poor ground related to sensor power/reference circuit

Fault status

⚠️ Status

ECM detected reference voltage for Sensor B is out of expected range or intermittent. Voltage may be too low, too high, or unstable relative to the ECM's reference thresholds.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 0.5-2.0 hours

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P06A7 — Reference voltage of sensor B - Circuit range/performance