C1293 — ABS pump motor request circuit fault

Causes

• Blown fuse or faulty relay for ABS pump power or control circuit
• Open or shorted wiring in the pump motor request/control circuit
• Corroded, loose, or damaged connector at ABS pump motor or module
• Failed ABS pump motor (stator/brushes or winding open)
• Faulty ABS control module or internal driver transistor
• Poor ground at pump motor or ABS module

Symptoms

• ABS warning lamp illuminated (may be steady)
• Traction control / StabiliTrak warning lamp illuminated
• Loss of ABS function; ABS does not activate during braking events
• No audible pump motor noise when ABS commanded
• Possible altered brake pedal feel during ABS events
• Vehicle may disable traction/ABS features or enter limp mode

What to check

• Retrieve all ABS and related codes with a capable scan tool; record freeze frame and status bits
• Visually inspect ABS pump motor connector, harness, fuses, and relay for damage, corrosion, or loose pins
• Check related fuses and relays for continuity and correct operation
• Backprobe pump motor connector and ABS module command connector with ignition ON and while commanding pump from scan tool
• Measure supply voltage at pump motor power pin (should be near battery voltage)
• Measure resistance of pump motor winding with battery disconnected

Signal parameters

• Battery voltage on pump power feed typically ~12–14 V with ignition ON or during pump run
• Pump motor request/control circuit often a switched ground or PWM from ABS module — inactive ~battery voltage, active ~0–1 V (ground) or PWM 0–100% (varies by model)
• Pump motor coil resistance (typical small DC motor) usually low — commonly in the range of ~1–10 Ω (vehicle-specific)
• When commanded, current draw should rise (motor run current) — near zero indicates open circuit, very high indicates shorted motor or locked rotor
• If PWM is used, frequency commonly 50–500 Hz (vehicle-specific)

Similar codes