P0671 on Toyota Grand Highlander: Fix & DLC Location
Factory diagnostic troubleshooting wire for fault code P0671 (P0671: Cylinder 1 Glow Plug Circuit Malfunction) specifically on the Toyota Grand Highlander (2024–2026, 2.4L Turbo / 2.5L Hybrid / Hybrid MAX 362HP Turbo AWD).
1. Symptoms of P0671 on Toyota Grand Highlander
When the Engine Control Module (ECM/PCM) on your Toyota Grand Highlander (2.4L Turbo / 2.5L Hybrid / Hybrid MAX 362HP Turbo AWD) logs fault code P0671, drivers commonly observe:
2. Most Likely Causes on Toyota Grand Highlander
Historical warranty claims and technical repair bulletins for Toyota Grand Highlander point to the following failure distribution:
3. Step-by-Step DIY Repair Guide for Toyota Grand Highlander
Interface with the diagnostic port or system console using verified scanning hardware. Record freeze-frame data, active sub-codes, and timestamps to isolate whether P0671 is static or intermittent. on the Toyota Grand Highlander equipped with 2.4L Turbo / 2.5L Hybrid / Hybrid MAX 362HP Turbo AWD.
Visually inspect the physical component (Cylinder 1 Glow Plug), connector pins, and associated wiring harnesses for signs of corrosion, thermal melting, or loose grounding clips. on the Toyota Grand Highlander equipped with 2.4L Turbo / 2.5L Hybrid / Hybrid MAX 362HP Turbo AWD.
Measure reference voltages and resistance thresholds against manufacturer factory specifications. Replace any component failing nominal impedance tolerances. on the Toyota Grand Highlander equipped with 2.4L Turbo / 2.5L Hybrid / Hybrid MAX 362HP Turbo AWD.
Install genuine OEM replacement hardware or execute registry / service commands. Ensure all mounting bolts are torqued to factory specifications. on the Toyota Grand Highlander equipped with 2.4L Turbo / 2.5L Hybrid / Hybrid MAX 362HP Turbo AWD.
Erase the fault code from non-volatile memory. Perform a standard verification cycle (e.g. 15-minute mixed drive or system stress benchmark) to ensure monitors reset to 'Ready' state without recurrent fault flags. on the Toyota Grand Highlander equipped with 2.4L Turbo / 2.5L Hybrid / Hybrid MAX 362HP Turbo AWD.
Other Common Fault Codes on Toyota Grand Highlander
Frequently diagnosed powertrain, emissions, and sensor trouble codes logged on the Toyota Grand Highlander:
4. Toyota Grand Highlander P0671 FAQs
What causes code P0671 to trigger on a Toyota Grand Highlander?
On the Toyota Grand Highlander (2.4L Turbo / 2.5L Hybrid / Hybrid MAX 362HP Turbo AWD), P0671 is most frequently caused by Component aging, oxidation, or degraded internal circuit element (Cylinder 1 Glow Plug) or Wiring harness abrasion, loose terminal pin, or ground voltage float.
Where is the OBD-II port located on my Toyota Grand Highlander?
On the Toyota Grand Highlander, the 16-pin DLC diagnostic connector is located Driver side lower knee panel above dead pedal. Plug in any standard OBD-II scanner with the ignition in the ON position to read freeze-frame parameters.
Can I safely drive my Toyota Grand Highlander with code P0671?
Yes, for temporary operations. However, resolve promptly to maintain optimal efficiency and prevent cascade failures. Given that P0671 carries a Moderate severity rating, we advise avoiding heavy towing or aggressive throttle inputs until sensor readings are verified.