Bendix EC-60 UDS 37 / SPN 627 FMI 4 — Battery Voltage Too Low During ABS

Code Details

Plain-English Meaning

System voltage dropped below threshold specifically during an ABS stop. The high current draw of multiple solenoids activating simultaneously was enough to drag voltage down, even though the system reads normal during regular driving.

The Bendix EC-60 table maps UDS code 37, blink code 06-03, J1587 251-04, and J1939 SPN 627 FMI 4 to this ABS/ATC/ESP diagnostic entry. The Bendix source indicates an ABS and/or ATC/ESP warning lamp can be on for this entry. The EC-60 continuously monitors wheel speed sensor circuits, pressure modulation valve output drivers, supply voltage quality, J1939 network data from the engine and transmission controllers, and internal self-diagnostic routines. When any monitored value falls outside its acceptable range — or a circuit does not respond as the module expects — the EC-60 logs a diagnostic trouble code and may disable the affected ABS, ATC, or ESP function. Bendix ACOM Pro or a compatible diagnostic interface is the required tool for reading live sensor data, running actuator tests, performing calibrations, clearing latched codes, and adjusting EC-60 configuration parameters. Generic J1939 scan tools can read the SPN/FMI but cannot access EC-60-specific live data screens or configuration settings.

Common Symptoms

• ABS lamp on after an ABS-active braking event
• Code stored rather than continuously active
• Charging system may read normal when checked at rest
• More common on vehicles with high electrical loads and aging batteries
• May correlate with cold weather when battery capacity is reduced

Possible Causes

Possible causes may include the items below. The list is not a parts diagnosis.

• Weak battery that cannot sustain voltage under the high current draw of multiple ABS solenoids firing simultaneously
• Undersized or high-resistance battery cables causing a large voltage drop at peak current
• Overloaded electrical system where ABS adds to an already near-limit demand
• Poor ground connection at the EC-60 that becomes significant under high current
• Corroded battery terminal or main fusible link with resistance that increases under load

First Checks

• Load-test the battery under a simulated high-current draw — a battery that tests marginal is likely the cause.
• Check voltage drop across battery cables, connectors, and main grounds under load, not just at rest.
• Measure EC-60 ground connection resistance — this joint is commonly overlooked.
• Review whether the vehicle has had recent high-draw accessories added (lift gates, refrigeration, hydraulics).
• Focus on current delivery capacity rather than steady-state voltage if the fault only occurs during genuine ABS events.

Can I Keep Driving?

Power supply faults suspend ABS and stability functions while the voltage condition persists — normal hydraulic or air base braking continues unaffected. If the vehicle is experiencing voltage-related issues, other safety systems may also be affected. Have the charging system and battery evaluated alongside the ABS repair — a recurring power fault that is cleared without addressing the root cause may produce intermittent loss of anti-lock protection without warning.

Related Lookup Pages

• FMI 4 explanation
• Bendix manufacturer hub
• ABS / ATC / ESP fault codes
• ABS Light symptom page
• Brake Warning Light symptom page
• Search this code