Code
B2808
LAND ROVER
B — Body
Pressure sensor power supply - short circuit to battery voltage
Views:
UK: 6
EN: 12
RU: 8
AI status
Completed
Completed
100%
Causes
- Damaged wiring harness with insulation abrasion contacting battery positive or fused feed
- Corroded or bridged connector pins at the pressure sensor
- Internal short in the pressure sensor (internal regulator/diode failure)
- Faulty fuse, fusible link, or relay supplying the sensor (stuck closed or shorted)
- Aftermarket wiring or recent repairs modifying the supply circuit
- Water ingress or contamination creating conductive path to battery voltage
Symptoms
- DTC B2808 stored in memory; may be present continuously or intermittently
- Affected pressure sensor not reporting valid data or stuck at a fixed value
- Related system degraded operation or limp mode depending on vehicle system using the sensor
- Possible MIL/warning lamp illuminated (depending on vehicle strategy)
- Intermittent faults that clear when connector is moved or ignition cycled
What to check
- Read and record all stored DTCs and freeze-frame/live data before clearing codes
- Visual inspection of wiring and connectors for damage, corrosion, burns, pin deformation or aftermarket splices
- Inspect routing where harness passes through body panels, engine mounts and near moving parts
- Check fuses/relays for the sensor power feed and verify correct fuse value and condition
- With ignition ON (engine OFF) measure voltage at the sensor supply pin vs battery positive and battery negative
- Check continuity between the sensor supply pin and battery positive (with ignition OFF) to detect a direct short/low resistance
Signal parameters
- Expected supply voltage: approximately battery voltage (~12V) at sensor supply terminal with ignition ON (engine off) — does not exceed battery voltage
- Sensor reference/signal (if separate) typically ~5V reference or signal range — this DTC specifically concerns supply line short to +12V
- Typical continuity: low resistance between supply fuse/relay output and sensor supply; high resistance (open/very high) between sensor supply pin and chassis ground
- If harness removed, measure resistance from sensor supply pin to battery + (should be near 0Ω through fused feed) and to chassis ground (should be high/OL unless other circuits present)
Diagnostic algorithm
- Retrieve DTCs, freeze frame and live data; note when the fault is active and related symptoms.
- Visually inspect sensor, connector and harness. Look for melted insulation, burn marks, corrosion, or aftermarket splices. Repair any obvious damage.
- With ignition OFF, disconnect the pressure sensor connector. Inspect connector pins for corrosion, bent pins or debris.
- With ignition ON (engine OFF) measure voltage at the sensor supply pin on the harness side: it should be ~12V only when supply is intended to be present. If permanent battery voltage is present when it should be switched, suspect feed/relay/fuse or short to battery.
- With ignition OFF, check continuity/resistance between the sensor supply pin and battery positive. Very low resistance may indicate intended fused feed; if continuity exists to battery positive independent of fuse/relay state, trace and isolate the short.
- Disconnect downstream modules and accessory circuits one at a time (or remove the fuse/relay) to isolate the shorted section of harness. Use back-probing and wiggle tests to reproduce the fault if intermittent.
- If harness and feed appear intact, connect a known-good replacement pressure sensor (or bench-test suspect sensor) and see if DTC clears. Replace sensor only after confirming internal short.
- Repair or replace damaged wiring, connectors or sensor as required. Replace blown fuses, faulty relays or repair control module power outputs if verified.
- After repairs, clear codes and perform function test/road test to confirm no reoccurrence.
- If fault persists and wiring/sensor verified, consider control module diagnostic procedures per manufacturer service information.
Likely causes
- Chafed or pinched harness where it contacts body/chassis causing insulation wear and contact with a fused +12V feed
- Connector corrosion/contamination allowing positive voltage to appear on the sensor supply pin
- Failed pressure sensor with internal short to battery rail
Fault status
Status
B2808 — Pressure sensor power supply short to battery voltage: the sensor supply circuit is seeing battery voltage when the control module expects a regulated/switchable feed; fault set when out-of-range condition is detected.
Repair difficulty: Medium
Diagnostic time: 0.5-2.0 hours
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