Code
B1299
LAND ROVER
B — Body
Sensor in the power supply - short circuit to ground
Views:
UK: 10
EN: 10
RU: 7
AI status
Completed
Completed
100%
Causes
- Damaged wiring harness with insulation chafing to chassis ground
- Corroded or contaminated connector causing a low-resistance path to ground
- Internal short in the sensor (sensor failed)
- Water ingress or moisture in connector or sensor assembly
- Incorrect or loose aftermarket accessory connections
- Faulty body/control module with an internal short (less common)
Symptoms
- Related system inoperative or reporting incorrect/no data
- Warning light(s) or message(s) on the dash for the affected system
- Intermittent or permanent fault stored in the control module
- Blown fuse (if the circuit is fused) or excessive current draw
- Possible loss of features controlled by the sensor (example: climate, lighting, safety systems depending on sensor)
What to check
- Read freeze-frame and full DTC list with a compatible scan tool to identify the affected sensor/circuit
- Visual inspection of wiring, connectors and sensor for damage, corrosion or moisture
- Check relevant fuses and replace if blown; note if fuse blows again
- Measure supply voltage at the sensor connector with ignition ON and engine OFF
- Perform resistance-to-ground check on the power feed with the battery disconnected
- Wiggle test harness while monitoring for changes in voltage or DTC status
Signal parameters
- Battery feed circuits: approx. 11–14.5 V with ignition ON (vehicle dependent)
- 5 V reference circuits (if used by the sensor): approx. 4.5–5.5 V
- Sensor supply line should show high resistance to ground (kΩ to open) with battery disconnected
- Short condition: near 0 Ω (low resistance) between sensor supply and ground or supply collapsed to ~0 V when powered
- Typical sensor current: small (milliamps) — large current draw indicates short or internal sensor failure
Diagnostic algorithm
- Use a scan tool to confirm B1299 and identify the specific sensor/circuit referenced by the code or freeze-frame data.
- Visually inspect the sensor, connector and wiring route for damage, corrosion, pinching or signs of water ingress.
- With ignition OFF and battery disconnected, measure resistance between the sensor power feed and chassis ground. A low resistance indicates a short to ground.
- Disconnect the sensor connector. Re-measure supply circuit resistance to ground. If resistance is now high, the sensor is likely shorted or the short is in the connector. If still low, the short is in the wiring harness or module.
- With ignition ON (engine OFF), backprobe the power feed at the disconnected connector and verify expected supply voltage. If voltage is near 0 V or fuse blows, isolate wiring sections to locate the short (use connector-by-connector isolation or a fused jumper for safe testing).
- Inspect and repair corroded pins, repair damaged wiring (cut out and splice or replace harness section), and reseal connectors. Replace the sensor if it is confirmed faulty.
- If wiring and sensor are good, suspect module internal fault — confirm with wiring diagrams and consider module bench testing or replacement as a last resort.
- Clear codes, test drive or cycle ignition to confirm the repair. Re-scan to ensure B1299 does not return.
Likely causes
- Chafed or pinched power feed where it contacts metal or ground
- Corroded terminal or bent pin at the sensor connector
- Failed sensor with internal short between supply and ground
- Connector contaminated by moisture or road salt creating a conductive path
Fault status
Status
Sensor power supply circuit short to ground — circuit pulled low
Repair difficulty: Medium
Diagnostic time: 0.5-2.5 hours
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