C1252 on Jeep
Brake Booster Pump Motor on Time Abnormally Long
C1252 on Jeep vehicles indicates brake booster pump motor on time abnormally long. Au7o has documented this code across 1 Jeep model — most commonly on Renegade. Toyota/Lexus manufacturer-specific chassis code on models with a hydraulic (pump-and-accumulator) brake booster — that includes the Electronically Controlled Brake (ECB) system on hybrids like the Prius, but also non-hybrid trucks and SUVs such as the FJ Cruiser and 4Runner, where it lives in the vehicle stability control section. The skid control ECU drives the brake booster pump motor to charge the accumulator, and Toyota's factory detecting condition is simply that the motor operates for 3 minutes or more, which means the system cannot build or hold target pressure. Toyota's factory trouble areas are the brake booster pump assembly, the hydraulic brake booster (accumulator pressure sensor), and the master cylinder solenoid, which houses the pump motor relay and the skid control ECU. Expect brake and ABS warning lights, a warning buzzer, and a hard, high pedal with reduced power assist — treat this as a braking-performance fault, not a nuisance light. Typical repair costs on Jeep range from $1,200 to $2,800, depending on the specific model and root cause.
Common Causes of C1252
- •Worn or failing brake booster pump motor / brake booster pump assembly (Toyota's first listed trouble area)
- •Internal leak in the hydraulic brake booster or accumulator that stops it holding pressure (on hybrids this typically pairs with C1391, Accumulator Leak)
- •Faulty accumulator pressure sensor inside the hydraulic brake booster, so the ECU never sees target pressure
- •High resistance, damage, or loose screws in the pump motor wire harness (MT+/MT-) between the booster and the pump
- •Master cylinder solenoid / skid control ECU fault (the pump motor relay is built into it)
- •Companion codes C1253, C1254, or C1256 set at the same time — Toyota says to diagnose and repair those first
C1252 on Jeep by Model
Jeep Renegade(1 issue)
- Power Transfer Unit (PTU) / Rear Drive Unit Failure and AWD Driveline Whine2015-2023
On 4x4/AWD Renegades (which share FCA's Small Wide platform with the Jeep Compass and Cherokee/Chrysler 200), the Power Transfer Unit and rear drive unit are a recurring weak point. Owners report a growing whine or growl that rises and falls with speed, a rumble/vibration felt around 30-35 mph, and eventually a 'Service 4WD' warning. The PTU actuator and internal gears, plus the electronically controlled rear-clutch pack, wear or seize, sometimes leaving the vehicle undrivable in AWD. Note: in the US market AWD Renegades use the 2.4L; the 1.4L was FWD-only.
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View C1252 across all makes →Frequently Asked Questions
What does C1252 mean on Jeep?▼
C1252 stands for "Brake Booster Pump Motor on Time Abnormally Long." Toyota/Lexus manufacturer-specific chassis code on models with a hydraulic (pump-and-accumulator) brake booster — that includes the Electronically Controlled Brake (ECB) system on hybrids like the Prius, but also non-hybrid trucks and SUVs such as the FJ Cruiser and 4Runner, where it lives in the vehicle stability control section. The skid control ECU drives the brake booster pump motor to charge the accumulator, and Toyota's factory detecting condition is simply that the motor operates for 3 minutes or more, which means the system cannot build or hold target pressure. Toyota's factory trouble areas are the brake booster pump assembly, the hydraulic brake booster (accumulator pressure sensor), and the master cylinder solenoid, which houses the pump motor relay and the skid control ECU. Expect brake and ABS warning lights, a warning buzzer, and a hard, high pedal with reduced power assist — treat this as a braking-performance fault, not a nuisance light. On Jeep specifically, this code is documented across 1 model.
What causes C1252 on Jeep vehicles?▼
Common causes on Jeep: Worn or failing brake booster pump motor / brake booster pump assembly (Toyota's first listed trouble area), Internal leak in the hydraulic brake booster or accumulator that stops it holding pressure (on hybrids this typically pairs with C1391, Accumulator Leak), Faulty accumulator pressure sensor inside the hydraulic brake booster, so the ECU never sees target pressure, High resistance, damage, or loose screws in the pump motor wire harness (MT+/MT-) between the booster and the pump, Master cylinder solenoid / skid control ECU fault (the pump motor relay is built into it). Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix C1252 on a Jeep?▼
Repair costs on Jeep range from $1,200 to $2,800, depending on the specific model and root cause.
Which Jeep models have C1252 documented?▼
Au7o has documented C1252 on 1 Jeep model: Renegade.