What Does B1298 Mean?
B1298 indicates the Body Control Module (BCM) has detected that a power supply sensor circuit is seeing battery voltage when it should not. This occurs when the sensor signal wire or circuit has a direct short to battery power, causing an abnormally high voltage reading. The BCM monitors various power supply sensors to ensure proper voltage levels for system operation and component protection.
Common Causes
45%
Damaged or chafed wiring harness causing sensor signal wire to contact a power wire or terminal
30%
Faulty power supply sensor with internal short circuit to power pin
15%
Corroded or damaged connector terminals causing cross-circuit contamination between power and signal pins
10%
BCM internal circuit failure or software corruption causing false voltage detection
Diagnostic Steps
1
Step 1: Perform visual inspection of all wiring harnesses related to power supply sensors, checking for chafed insulation, damaged wires, melted connectors, or signs of previous improper repairs near power distribution points
2
Step 2: Disconnect the power supply sensor connector and use a digital multimeter to measure voltage on the signal wire at the harness side with ignition on - should read 0V or reference voltage (typically 5V), not battery voltage (12V+)
3
Step 3: If battery voltage is present at disconnected harness, trace the signal wire from the sensor to the BCM checking for pinch points, routing near high-current wires, and inspect all intermediate connectors for terminal spread or contamination
4
Step 4: If no voltage found at harness with sensor disconnected, measure resistance of the sensor itself between signal and power pins - should show high resistance (typically >10k ohms), low resistance indicates internal sensor short
5
Step 5: Clear the code and monitor live data for the power supply sensor voltage reading with sensor reconnected - voltage should be stable at reference level, spikes to battery voltage confirm intermittent short
6
Step 6: After repair, verify proper sensor voltage readings under various electrical load conditions (lights, HVAC, accessories on) and perform BCM relearn procedure if required by manufacturer
Estimated Repair Cost
$100 - $450
Parts + labor, varies by vehicle and location
B1298 indicates the Body Control Module (BCM) has detected that a power supply sensor circuit is seeing battery voltage when it should not. This occurs when the sensor signal wire or circuit has a direct short to battery power, causing an abnormally high voltage reading. The BCM monitors various pow...
The most common cause of B1298 (Power Supply Sensor Circuit Short To Battery) is: Damaged or chafed wiring harness causing sensor signal wire to contact a power wire or terminal
Typical repair costs for B1298 range from $100 to $450, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Vehicle is generally safe to drive but may experience electrical system malfunctions, incorrect readings, or component protection shutdowns. Repair should be completed within a few days to prevent potential damage to the BCM or other electrical components from voltage irregularities.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to B1298 to identify the root cause.
OBDHut Mobile App
Scan codes directly from your car with the OBDHut app.
Coming Soon
Quick Info
Category
Body
System
Body Control Module / Electrical System
Difficulty
Type
Manufacturer
Recommended Tools
OBD2 Scanner
A quality scan tool helps you read codes, view live data, and clear faults.
