Code Definition

C2129 (16) — Battery Voltage Circuit Voltage Below Threshold

System: Chassis  |  Type: Generic (OBD-II Standard)  |  Make: Jeep

About C2129

C2129 is a generic (obd-ii standard) chassis diagnostic trouble code recorded for Jeep vehicles. It belongs to the C-prefix family of codes, which covers chassis, braking, steering, suspension, or stability-control faults.

When C2129 is stored, the module has detected a signal or supply voltage lower than the expected operating range.

Scanning & clearing: Chassis (C) codes are stored in the ABS, traction control, or stability-control modules. An enhanced or OEM-level scan tool is usually required to read and clear them.

Because C2129 is a generic OBD-II code, its base definition is shared across manufacturers. The specific diagnostic steps, reference values, and repair procedures can vary by vehicle, and the TaT Diagnostic Assistant includes verified procedures submitted by working technicians.

Code Information

The ABS or Electronic Stability Control (ESC) module continuously monitors its battery voltage supply circuit to ensure system operation within a calibrated voltage range. DTC C2129 is set when the module detects battery supply voltage below the minimum threshold for a defined period while the ignition is on. This low voltage condition can compromise module performance and trigger protective shutdown strategies that disable ABS, traction control, and stability functions. Driver symptoms can include illumination of the ABS, brake, and stability warning lights, intermittent loss of stability and...

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