Suzuki Wagon R Manual page 1796

DTC C1015 – G Sensor Circuit
DESCRIPTION
If the signal voltage of G sensor while at a stop does not vary from that while running, this DTC is set.
Therefore, this DTC may be set when a vehicle is lifted up and its wheel(s) is turned. In such case, clear the
DTC and check again.
INSPECTION
1) Ignition switch OFF.
2) Check for proper connection from harness to control module.
3) If OK, substitute an ABS hydraulic unit/control module assembly with correct part number.
4) Recheck system.
ANTILOCK BRAKE SYSTEM (ABS) 5E-15