P1673 — ABS Lamp Control Circuit

P1673 — ABS Lamp Control Circuit. P1673 concerns the ABS warning-lamp circuit and does not by itself prove that the ABS hydraulic system has failed.

For Ford vehicles

ABS lamp control circuit

vehicle

Is it safe to drive?

Caution - ABS warning circuit fault P1673 concerns the ABS warning-lamp circuit and does not by itself prove that the ABS hydraulic system has failed. If braking feels normal and no additional ABS faults are present, drive cautiously to a repair shop and avoid relying on ABS in slippery conditions.

Typical symptoms

The ABS warning lamp remains illuminated after startup
The ABS warning lamp fails to illuminate during the expected bulb check
An OBD2 scanner reports P1673 as a stored or pending ABS lamp circuit fault
The ABS lamp may flicker or behave inconsistently if the wiring or connector is intermittent

Common causes

A failed ABS warning-lamp bulb, LED, or integrated lamp assembly
An open or high-resistance connection in the ABS lamp control wiring
A short to power or ground within the ABS lamp circuit
A blown circuit-protection fuse or unreliable chassis ground
An internal lamp-driver or lamp-control output failure in the ABS control module

How to diagnose with an OBD scanner

Confirm P1673 with a scanner Connect an OBD2 scanner, ELM327 adapter, or AIScanAuto-compatible tool and read stored, pending, and manufacturer-specific ABS codes. Confirm P1673, document any additional ABS faults, and save freeze-frame information before clearing codes.
Verify warning-lamp operation Perform the specified key-on or startup bulb check and compare the ABS lamp behavior with the vehicle's service information. Confirm whether the lamp remains commanded on or fails to illuminate when P1673 is present.
Inspect the lamp circuit Inspect the ABS lamp, socket or integrated assembly, wiring harness, connectors, and related fuse. Look for burned terminals, loose pins, damaged insulation, corrosion, water intrusion, and chafing near the ABS control module.
Test power, ground, and control wiring Using the correct wiring diagram, test voltage, ground continuity, and the lamp-control signal at the relevant connector. Repair any open, shorted, or high-resistance wiring and verify that the ABS lamp circuit is not loading the module output incorrectly.
Check the ABS lamp driver If the lamp, fuse, grounds, connectors, and wiring all pass, check whether the ABS control module commands the lamp correctly. An incorrect command or failed internal lamp driver can identify P1673, but the module should not be replaced solely from the code.

Approximate repair cost

A rough independent-shop estimate for diagnosing and repairing P1673 is USD $120-$450 when the lamp, connector, fuse, or wiring is at fault. If ABS control-module replacement is required after testing, the total may be roughly USD $700-$1,400. These figures are estimates rather than verified quotes, and labor, parts, and prices vary by region.

Common questions

Does P1673 mean the ABS pump or hydraulic system is defective?

Not necessarily. P1673 identifies an ABS lamp control circuit fault, so the pump and hydraulic valves may still be functional; those systems require separate diagnostic evidence.

Can I continue driving with P1673 stored?

If P1673 is the only code, the brake pedal feels normal, and the ABS lamp issue is the sole concern, cautious driving to a shop is generally reasonable. Avoid high-speed or poor-weather driving if ABS operability is uncertain.

Why is the ABS lamp on when no other ABS code appears?

The lamp circuit can have its own fault, including a defective bulb, bad ground, damaged wiring, or an internal ABS module lamp driver. P1673 can therefore illuminate the lamp without another ABS system failure being recorded.

Should the ABS control module be replaced first for P1673?

No. First test the lamp, fuse, grounds, connectors, wiring continuity, and control signal. Replacing the ABS module before completing those checks would be premature and unnecessarily expensive.

P1673 — ---

When your vehicle's self-diagnostic system finds something wrong with a sensor or actuator circuit, it often sets trouble code P1673. This code falls under the manufacturer-specific category, which means it relates to systems that vary from one automaker to the next. The engine control unit (ECU) continuously monitors electrical circuits throughout the vehicle, comparing live sensor readings and actuator feedback against factory-programmed acceptable ranges. When those readings fall outside normal parameters for the defined period, the ECU flags the fault and stores P1673 in its memory.

The way P1673 gets set follows a predictable pattern. The control module tracks the behavior of the circuit over multiple drive cycles rather than triggering on a single bad reading. This prevents false alarms from temporary electrical glitches. When the threshold gets crossed consistently, the ECU writes the code and captures a freeze frame snapshot simultaneously. That snapshot records engine speed, load calculation, coolant temperature, and vehicle speed at the exact moment the fault occurred. Technicians use that data to recreate the failure conditions during diagnosis, which dramatically cuts troubleshooting time.

Symptoms of P1673

The system tied to the fault either stops working entirely or behaves inconsistently
The Check Engine Light illuminates on your dashboard
Fuel economy drops noticeably in some vehicle applications
Performance may degrade, or the vehicle could enter limp-home mode depending on which component failed
In rare cases, related safety systems may show warning indicators
Starting difficulties can occur if the affected circuit controls cranking functions

What Triggers P1673

The root causes typically trace back to electrical problems rather than mechanical wear. Control module driver circuits can fail internally, losing the ability to send or receive proper signals. Wiring harness issues account for a large percentage of cases—open circuits, short-to-ground faults, or intermittent breaks prevent reliable communication between sensors and the ECU. Connector pins suffer from corrosion, bent contacts, or backing-out of the housing, all of which create resistance or complete signal loss. A blown fuse feeding the affected circuit will obviously prevent proper operation and trigger this code.

Diagnosing P1673

Working through this code systematically prevents unnecessary parts replacement and wasted money.

Connect a quality OBD2 scanner and verify P1673 is present in the stored codes. Before clearing anything, record the freeze frame data—this snapshot reveals what conditions existed when the failure happened.
Pull all other stored codes as well. Related trouble codes often point toward the true underlying cause rather than just the symptom. Check for any technical service bulletins (TSB) specific to your make, model, and year—manufacturers publish these updates when known issues have factory-approved solutions or software patches.
Perform a thorough visual inspection of the wiring harness and connectors associated with the affected circuit. Look for damaged insulation, scraped wires, green corrosion buildup, or connectors that don't seat securely.
Test electrical values at the component connector using a multimeter. Check for proper reference voltage from the control module, verify ground continuity, and measure signal voltage against factory specifications.
Conduct a wiggle test on the harness while monitoring live data on your scanner. Any signal dropouts or wild fluctuations indicate broken wires inside the insulation that only move when flexed.
Clear the code after repairs and drive the vehicle through a complete drive cycle, including the specific conditions from your freeze frame data. The code must stay cleared and not return during normal operation.

Repair Options and Costs

Addresses the most frequent culprits before considering expensive components:

Wiring repair or connector replacement: $80–$250
Sensor or actuator replacement: $150–$500
Control module repair or replacement: $300–$1,000

Prices reflect typical labor rates at independent shops in the United States. Parts costs vary by vehicle make—dealership parts typically run higher than quality aftermarket alternatives.

The total cost to resolve P1673 typically falls between $80 and $1,000 depending on what actually failed. Wire harness repairs and connector work occupy the lower end of that range and resolve the majority of cases. Control module replacement represents the most expensive scenario but occurs less frequently. Proper diagnosis before purchasing parts ensures you tackle the actual problem rather than guessing and replacing good components.

Driving Safety Assessment

Most vehicles remain drivable when P1673 is active, though you may notice reduced functionality or a minor performance drop. The auxiliary system tied to this fault code typically goes offline without affecting core drivetrain operations. However, if the code triggers additional warnings for braking, steering, or causes stalling or no-start conditions, treat it as a priority repair. Don't ignore warning lights that indicate safety systems are compromised.