B1B62

Code

LAND ROVER B — Body

Nitrous oxide (NOX) pollution sensor input circuit

Brand: LAND ROVER

Type: B — Body

Views: UK: 14 EN: 22 RU: 14

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Page language: EN

Causes

Open or shorted NOx sensor signal circuit
Faulty NOx sensor (failed internal electronics)
Damaged, corroded or loose connector(s) at the sensor or ECU
Failed NOx sensor heater or heater circuit fault
Supply power or ground fault to sensor or heater (blown fuse, relay, wiring)
Exhaust leak upstream of sensor affecting readings

Symptoms

MIL (check engine light) illuminated
Reduced emissions system performance; failed emissions test
Possible diagnostic limp mode or reduced engine power in severe cases
SCR/DEF warning messages (if equipped)
Stored freeze-frame/related aftertreatment trouble codes
Unusual exhaust odors if DEF/urea not dosing correctly

What to check

Read and record stored codes and freeze-frame data with a capable scan tool/supporting manufacturer data
Inspect sensor connector and harness for corrosion, damage, pin push-out or water ingress
Check DEF/urea level and SCR system warnings (if present)
Visual inspection for exhaust leaks or physical damage upstream of sensor
Verify relevant fuses and relays for sensor/heater circuits
Check for related codes (heater circuit, communication faults)

Signal parameters

NOx sensor signal: should produce a voltage/current or CAN/ppm value within manufacturer specified range — consult service data (typical sensors use low-voltage/0–5 V or digital ppm output)
Heater circuit: measurable continuity/resistance per manufacturer spec (often low ohms); heater should draw specified current when commanded
Supply voltage to sensor: key-on or engine-running supply voltage approx battery voltage (verify per wiring diagram)
Signal behavior: sensor value should change when engine load/NOx production changes (warm engine)
Response time: sensor should respond within seconds when conditions change — consult manufacturer limits

Diagnostic algorithm

Safety: allow exhaust and components to cool as needed; wear PPE.
Connect a manufacturer-level scan tool. Clear codes, then re-run to confirm B1B62 persists and capture freeze-frame/live-data.
Inspect wiring and connector at NOx sensor for corrosion, bent pins, heat damage, foreign deposits, or water intrusion. Repair or replace damaged connectors.
Verify power and ground for sensor/heater at the connector with key on/engine running. Check fuses and relays. Repair any open/low-voltage circuits.
Measure heater resistance against service spec. If open/short or out of range, replace sensor.
Backprobe signal wire and monitor live sensor output while warming engine and changing load. Look for valid, stable signal and appropriate change with load. Use oscilloscope if available to detect intermittent/noise.
If signal is absent or shorted, perform continuity/resistance checks from sensor connector to ECU input pin per wiring diagram; repair wiring faults (shorts to ground/power) as required.
Inspect exhaust upstream for leaks or contamination that could affect readings; check DEF/urea dosing system operation and filters for contamination.
If wiring and supply are correct but signal remains invalid, replace NOx sensor with OEM-specified unit and re-test.
After repairs, clear codes, perform regeneration/initialization procedures if required by manufacturer, and road-test to verify repair. Re-scan to confirm no return of the fault.
If fault persists after sensor and wiring replacement, consider module input test or module replacement following manufacturer diagnostics.

Likely causes

Corroded or disconnected sensor connector
Open/short in sensor signal or heater wiring harness
Failed NOx sensor (common on high-mileage vehicles)
Blown fuse or bad relay supplying sensor heater
Contamination or physical damage to sensor tip

Fault status

⚠️ Status

B1B62 — NOx pollution sensor input circuit: sensor signal is open, shorted, out-of-range or intermittent. MIL may be set and emissions control/aftertreatment performance affected.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 1.5-3.0 hours

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