DTC C1245
Circuit Description

The Tire Pressure Monitor (TPM) system uses the Electronic Brake Control Module (EBCM), and the ABS wheel speed sensor inputs to monitor tire pressure. The EBCM contains software to calculate relative tire pressure differences. The EBCM monitors the ABS wheel speed sensor inputs, which will all be the same as the learned calibration if the tire pressures stay the same. If the pressure increases or decreases in one tire so too will that tire's circumference and radius, which causes that wheel speed sensor input to change. The EBCM recognizes this change in wheel speed as a tire pressure condition.
Conditions for Running the DTC

No ABS or TCS malfunctions present.
The calibration process is at least partially complete.
The vehicle speed is between 24-145 km/h (15-90 mph).

Conditions for Setting the DTC

The EBCM detects a tire pressure difference in one tire of 69 kPa (10 psi) higher or lower than the other three.
Loss of, or low system battery voltage.

Actions Taken When the DTC Sets

A DTC C1245 is stored in memory.
The systems monitor displays the TIRE PRESS indicator, or the DIC displays the CHECK TIRE PRESSURE warning message, if equipped.
The TPM system is disabled.

Conditions for Clearing the DTC

A current DTC will clear when the TPM system has been reset.
A history DTC will clear after 100 consecutive malfunction free ignition cycles and the TPM system has been reset.
Using the scan tool

Diagnostic Aids

Any of the following conditions can also cause this DTC to set.

The tire pressures have been adjusted without resetting the TPM system.
The tires have been rotated or replaced without resetting the TPM system.
Rough or slippery road conditions such as dirt, gravel, wet, snow, or ice.
The tires are out of balance.
The suspension is out of alignment.