Left Front Tire Pressure Sensor Fault
Table of contents
B2868 MERCURY Possible Causes
- Low tire pressure
- Tire pressure sensor is missing or damaged
- Spare tire is installed as a road wheel
- Incorrect tire pressure sensor is installed
- Tire pressure sensor installed incorrectly
- Faulty Left Front Tire Pressure Sensor
How do I fix code B2868 MERCURY?
Check the “Possible Causes” listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector’s pins.
Tech Notes
- When the tire pressure warning light comes on solid and message center displays LOW TIRE PRESSURE, check the air pressure of all tires and adjust to the specified cold pressure listed on vehicle certification label (found on drivers door or door pillar). Drive the vehicle at 20 mph (32 km/h) for at least 2 minutes. If the vehicle has been stationary for more than 30 minutes, a TPM sensor Activation procedure may be needed. When the tire pressure warning light flashes for 70 seconds and then remains illuminated, after bulb-check has been performed and message center displays warning messages, there is a malfunction in the TPM system.
Cost of diagnosing the B2868 MERCURY code
The cost of diagnosing the B2868 MERCURY code is 1.0 hour of labor. The auto repair labor rates vary by location, your vehicle’s make and model, and even your engine type. Most auto repairs shops charge between $75 and $150 per hour.
Possible Symptoms
- Tire Pressure Monitor System (TPMS) Warning Light ON
B2868 MERCURY Description
The Tire Pressure Monitor (TPM) system monitors the air pressure in the 4 road tires with wheel-mounted tire pressure sensors. The sensors transmit radio frequency signals to the Smart Junction Box (SJB) approximately every 60 seconds when the vehicle speed exceeds 20 mph (32 km/h). If vehicle is stationary for more than 30 minutes, the sensor will enter into a sleep mode and stop transmitting.
Each tire pressure sensor transmission is compared against a low-pressure limit (pressure listed on vehicle certification label minus 25 percent, which will be about 6-9 psi). If it is determined that the tire pressure has fallen below this limit, the SJB sends a message to the instrument cluster, which then illuminates the low pressure warning indicator and displays the appropriate message(s) in the message center (if equipped).