Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Pinpoint Test ZA: C0078:56: Notes
Normal Operation and Fault Conditions
The BCM is programmed with vehicle tire size information during the module configuration step. The BCM shares tire size information with other module over the HS-CAN. When this DTC sets, the ABS module sends a message to the IPC to illuminate the ABS warning indicator.
REFER to: Anti-Lock Brake System (ABS) and Stability Control - System Operation and Component Description .
DTC Fault Trigger Conditions
| DTC | Description | Fault Trigger Condition |
|---|---|---|
| ABS C0078:56 | Tire Diameter: Invalid/Incompatible Configuration | If the tire size message sent to the ABS module from the BCM contains invalid data, this DTC sets. |
Possible Sources
- Temporary or mini-spare tire in use
- Under inflated tires
- Mismatched sized wheels and tires
- Network communication concern
- Incorrect BCM configuration
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.