Start by checking 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.
The cost to diagnose the B1048 code is 1.0 hour of labor. The auto repair's diagnosis time and labor rates vary by location, vehicle's make and model, and even your engine type. Most auto repair shops charge between $75 and $150 per hour.
The Instrument Panel Cluster (IPC) uses 3 basic messaged inputs to control the brake warning indicator. The first two are the parking brake warning indicator switch and the brake fluid level switch. The third is for the Electronic Brake Distribution (EBD) function controlled by the ABS module. The parking brake warning indicator switch and the brake fluid level switch status are sent from the Body Control Module (BCM) over the High Speed Controller Area Network (HS-CAN). The EBD message is sent from the ABS module over the HS-CAN.
The parking brake warning indicator switch is hardwired to the BCM through a single signal circuit while using a separate ground to control the input. The brake fluid level switch is hardwired to the BCM through separate signal and return circuits while using a separate ground to control the input.
The BCM provides a reference voltage to both the parking brake warning indicator switch and the brake fluid level switch. When the parking brake is applied, the parking brake warning indicator switch closes to ground, pulling the parking brake signal circuit low. When a low brake fluid level condition exists, the brake fluid level switch closes to ground, pulling the signal and return circuits low. If the brake fluid level switch is disconnected, the BCM reference voltage sent to the brake fluid level switch is sent high and the BCM sets DTC B1048:7B. When the BCM detects either the brake fluid level signal or the parking brake signal circuits low, or the brake fluid level signal and return circuit high, the BCM sends the IPC a brake warning indicator on request.
When the ABS module detects a base brake system concern or other ABS related concerns that affect the EBD function, the ABS module sends a brake warning indicator on request to the IPC to illuminate the brake warning indicator and the ABS warning indicator.
Need more information on how to fix the B1048 code? Get Access to Factory Service Manuals
Get the B1048 code diagnosed by a professional: Find a repair shop in your area