What Does B2248 Mean?
This code indicates that the Body Control Module (BCM) has detected an electrical fault in the control circuit for the heated windshield relay coil. The BCM monitors the relay coil circuit for proper voltage and resistance, and has identified either an open circuit, short circuit, or excessive resistance preventing the relay from being energized. This prevents the heated windshield system from activating when commanded.
Common Causes
35%
Faulty heated windshield relay with internal coil failure or corroded terminals
30%
Open or damaged wiring between BCM and heated windshield relay coil
20%
Poor ground connection or corroded ground point in relay coil circuit
10%
BCM internal driver circuit failure for relay control output
5%
Blown fuse or fusible link in relay coil power supply circuit
Diagnostic Steps
1
Step 1: Locate the heated windshield relay in the fuse/relay box and perform visual inspection for corrosion, burned terminals, or physical damage. Remove relay and inspect socket terminals for corrosion or melting.
2
Step 2: With relay removed and ignition on, use a digital multimeter to verify battery voltage (12-14V) at the relay coil power supply terminal in the socket. Check for proper ground at the relay coil ground terminal (should read less than 0.5 ohms to battery negative).
3
Step 3: Test the relay coil resistance with an ohmmeter - typical reading should be 70-120 ohms. If out of range or open circuit, replace relay. If relay tests good, proceed to circuit testing.
4
Step 4: With relay removed and ignition on, command the heated windshield system on using scan tool bidirectional controls (if available) while measuring voltage at the BCM control terminal in relay socket. Should see switching between 0V and 12V. No voltage change indicates BCM driver circuit fault or open wire.
5
Step 5: If BCM control signal is present, install known-good relay and verify system operation. If no control signal from BCM, check continuity of wire between BCM connector and relay socket (should be less than 5 ohms). Inspect harness for chafing or pinched wires.
6
Step 6: After repair, clear codes, cycle heated windshield system on/off multiple times, and verify no codes return. Test system operation under load to confirm proper relay engagement.
Estimated Repair Cost
$75 - $450
Parts + labor, varies by vehicle and location
This code indicates that the Body Control Module (BCM) has detected an electrical fault in the control circuit for the heated windshield relay coil. The BCM monitors the relay coil circuit for proper voltage and resistance, and has identified either an open circuit, short circuit, or excessive resis...
The most common cause of B2248 (Heated Windshield Relay Coil Circuit Failure) is: Faulty heated windshield relay with internal coil failure or corroded terminals
Typical repair costs for B2248 range from $75 to $450, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Vehicle is safe to drive with this fault as it only affects windshield heating comfort feature. Repair can be scheduled at convenience, though may impact visibility in cold/icy conditions if windshield defroster function is compromised.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to B2248 to identify the root cause.
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Quick Info
Category
Body
System
Body Electrical System
Difficulty
Type
Generic (SAE)
Recommended Tools
OBD2 Scanner
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