P1672 — Cooling Fan Relay Short Circuit

Does P1672 mean the cooling fan motor is bad?

Not necessarily. P1672 may be caused by the relay, its socket, or a shorted control-circuit wire, so those components should be tested before replacing the cooling fan motor.

Can the vehicle be driven with P1672?

If the temperature gauge stays normal and no coolant warning appears, a short trip may be possible, but overheating can occur suddenly. Stop the vehicle safely if the temperature begins climbing.

How is a shorted cooling fan relay confirmed?

Use the vehicle wiring diagram to backprobe the relay connector, isolate each circuit, and test the relay for an unintended short. P1672 should not be cleared until the cause is identified and repaired.

Should the cooling fan relay always be replaced?

Only replace the engine cooling fan relay if continuity and control tests show it is defective. A damaged wire, corroded connector, or control-circuit short may resolve P1672 without relay replacement.

When your scan tool pulls code P1672, it indicates a fault inside the control module's sensor and actuator circuit — specifically a problem within the component group that OBD2 standards classify as "---." This isn't a fault with a single sensor or switch; rather, it points to a broader wiring or circuit issue that the engine control unit has detected during normal operation.

The ECU constantly watches this circuit while you drive. It compares real-time sensor and actuator data against pre-programmed acceptable ranges. If readings stay out of bounds long enough across multiple drive cycles, the module logs P1672 and illuminates the Check Engine light. When this happens, the freeze frame data stored alongside the code is invaluable — it captures engine RPM, load, temperature, and vehicle speed at the exact moment the fault occurred, giving you a precise starting point for your investigation.

Symptoms of P1672

When P1672 sets, you may notice one or more of the following conditions:

• The Check Engine light stays on
• The affected system cuts out intermittently or stops working entirely
• Limp-home mode activates if the fault involves a critical component
• Fuel economy drops noticeably in certain cases
• Reduced drivability or sluggish response depending on which circuit is affected

Common Causes

The most frequent culprits behind P1672 are straightforward electrical problems. Here's what to check, starting with the most likely:

• A corroded, loose, or physically damaged connector at the sensor or actuator
• An open circuit — broken wire somewhere in the harness
• A short circuit — wiring grounding out against the chassis or another wire
• Poor ground connection at the affected component
• A blown fuse protecting the circuit

Diagnosing P1672

Follow these steps to pin down the exact cause before replacing any parts:

1. Hook up your OBD2 scanner and verify P1672 is stored. Record the freeze frame data — this snapshot shows engine conditions when the fault triggered and guides your diagnosis.
2. Pull all stored and pending codes from the module. Related codes often expose the real problem. Also search for technical service bulletins (TSBs) specific to your make, model, and year — manufacturers publish service updates for many P0xxx codes that include software patches or known fixes.
3. Inspect the wiring harness and connectors tied to the affected circuit. Look for chafed insulation, broken strands, corrosion buildup, or pins that don't seat firmly.
4. Test reference voltage, ground integrity, and signal continuity at the component itself using a multimeter. Compare your readings to factory specifications.
5. Perform a wiggle test while monitoring live data — gently move the harness and connectors to expose intermittent dropouts that point to broken wires or loose contacts.
6. Clear the code and complete a full drive cycle, replicating the conditions from your freeze frame data. If P1672 returns, the fault is still present.

Repair Options and Costs

Address the cheapest probable causes first. Swapping expensive components without confirming the underlying wiring issue wastes money:

Total Repair Cost for P1672

Your actual spend hinges on which part failed. Based on independent shop labor rates in the United States:

• Fixing damaged wiring or connectors: $80–$250
• Replacing a faulty sensor or actuator: $150–$500
• Repairing or replacing the control module: $300–$1,000

Most P1672 fixes land somewhere in that full range. A proper diagnosis before you buy parts is the best way to avoid overspending — the most expensive repair on the list is almost never the first place you should look.

Can You Drive With P1672?

The severity level for this code is short, meaning most vehicles remain operational even with P1672 stored. You might experience reduced performance, an inoperative auxiliary system, or slightly worse fuel economy. However, if the vehicle stalls unexpectedly, fails to start, or triggers any brake or steering-related warnings, treat this as an urgent issue and stop driving immediately. Have it towed to a shop for diagnosis.