Code
B29F1
MITSUBISHI
B — Body
Sequence error:pump current HI
Views:
UK: 13
EN: 16
RU: 11
AI status
Completed
Completed
100%
Causes
- Electrical short or partial short to battery voltage in pump motor circuit
- Faulty pump motor drawing excessive current (mechanical binding or internal failure)
- Failed pump motor relay or driver transistor in ABS/BCM/ECU
- Damaged wiring or poor connector (corrosion, high resistance, intermittent contact)
- Hydraulic blockage or seized pump causing mechanical overload
- Incorrect supply voltage (overvoltage) or weak ground
Symptoms
- ABS/ESP warning lamp illuminated
- Reduced or lost ABS function; traction control may be disabled
- Pump runs continuously or fails to run during ABS self-test
- Unusual noise from pump (grinding/squeal) or no noise when commanded
- Possible battery drain or blown fuse if short severe
What to check
- Read all ABS/vehicle codes and freeze frame / data at time of fault
- Visually inspect pump, harness, and connectors for damage, corrosion, or water ingress
- Check fuses and relays related to ABS/pump power
- Perform an actuator command/pump run test with a capable scan tool and observe behavior
- Measure supply voltage to pump and ground continuity at connector with pump commanded
- Measure pump motor current with a clamp meter during activation
Signal parameters
- Supply voltage to pump: should be close to battery voltage (~12 V nominal) during activation
- Pump motor current: normally a low-to-moderate surge during start then steady running current; manufacturer threshold exceeded triggers fault
- Command status: pump ON/OFF from ABS module (digital command signal)
- Duty cycle or PWM (if used) reported by module when controlling pump speed
Diagnostic algorithm
- Record freeze-frame data and clear codes. Reproduce fault with a road or bench test while monitoring live data.
- Visually inspect pump, connector, wiring harness, and related fuses/relays for damage or corrosion.
- With a scan tool, command the pump ON and observe module status and live current/power values. Note abnormal current or failure to operate.
- Measure voltage at the pump connector (positive and ground) during command. If voltage absent or low, trace supply/ground and test relay.
- Measure pump motor current with a clamp meter while the pump is commanded. Compare to expected (should be moderate; large spikes or sustained high current indicate problem).
- If high current is confirmed at the pump, disconnect pump connector and measure motor resistance across windings. Very low resistance suggests shorted winding; open or very high suggests wiring/connector issue.
- Inspect pump mechanically: remove/inspect for seized bearings, debris, or hydraulic blockage. Check fluid condition and valves.
- If wiring and pump appear OK, test/replace the pump relay and re-test. If driver transistor inside control module is suspected, consult service literature before replacing module.
- Repair or replace the faulty component (wiring, connector, relay, pump, or module) and retest to confirm the fault is cleared and no new codes appear.
Likely causes
- Pump motor seizure or internal wear causing high torque/current draw
- Shorted winding or internal electrical fault in pump motor
- Failed pump relay or power transistor causing uncontrolled current
- Damaged harness or corroded connector at pump or module
- Hydraulic line blocked or valve stuck increasing pump load
Fault status
Status
Sequence error — pump motor current higher than expected during commanded operation; action required to inspect pump circuit and mechanical condition.
Repair difficulty: Medium
Diagnostic time: 1.0-3.0 hours
Similar codes
Your experience will help others
+100 karma for a short comment :)
Was this AI description helpful?
Your feedback helps improve AI descriptions.
👍 Like
0
👎 Dislike
0
Send to email