HomeTrouble CodesC1097

C1097 — Abs Hydraulic Pump Motor Circuit Short Ground

Manufacturer-specificChassis

C1097 indicates the ABS (Anti-lock Braking System) control module has detected a short-to-ground fault in the hydraulic pump motor circuit. The pump motor is responsible for generating hydraulic pressure needed for ABS function.

Symptoms

What causes it — most likely first

1. Failed ABS hydraulic pump motor

The pump motor winding has internally shorted to ground, most commonly due to wear, age, or contamination. This is the most frequent cause of this code.

2. Damaged wiring or connector

The wiring harness or connector to the pump motor has been damaged, chafed, or corroded, allowing the circuit to short to ground.

3. Blown fuse or failed relay

The fuse powering the ABS pump motor has blown, or the pump relay has failed, causing abnormal circuit conditions.

4. Poor ground connection

The ground connection for the ABS pump motor is corroded, loose, or damaged, causing the circuit to find alternate ground paths.

5. Failed ABS hydraulic unit

The complete ABS hydraulic assembly (which includes the pump, valves, and control module) has failed internally, though this is less common than isolated pump failure.

6. ABS control module fault

The ABS electronic control module itself has failed and is incorrectly reporting a short-to-ground. This is a rare cause and should be diagnosed after other possibilities are ruled out.

How it's diagnosed

  1. Connect a scan tool and verify C1097 is present along with any other ABS-related codes
  2. Perform a visual inspection of the ABS pump motor wiring and connectors for damage, corrosion, or chafing
  3. Check all fuses and relays related to the ABS system and test them for proper operation
  4. Use a multimeter to test the pump motor winding for a short-to-ground condition (should show infinite resistance)
  5. Verify proper ground voltage at the pump motor connector with the circuit powered
  6. If wiring and motor test good, consider testing or swapping the ABS relay
  7. As a final step, the ABS control module may need to be checked or the entire hydraulic assembly may require replacement

Code facts & related codes

SystemChassis
StandardizationManufacturer-specific (P1/B1/C1/U1)

Frequently asked

Can I still drive my vehicle with C1097?

Yes, standard braking will continue to function, but the anti-lock feature will be disabled. You should drive cautiously and have the system diagnosed promptly.

Is the ABS control module (computer) usually the cause of C1097?

No. While some shops may suggest replacing the PCM/ECM for this code, it is almost never the culprit. The fault is almost always in the pump motor, wiring, or related electrical components.

Do I have to replace the entire ABS unit to fix this?

Often yes, because many vehicles have the pump motor integrated into the hydraulic assembly. However, on some vehicles the motor is serviceable separately. Check your specific vehicle's repair options before assuming full replacement is needed.

Can a weak battery or low system voltage cause this code?

Low voltage can contribute to electrical faults and may trigger false codes, but it would not typically cause a true short-to-ground in the pump motor circuit. Address any severe battery or charging system issues, but the underlying cause is usually a physical short or component failure.