Diesel Trouble Codes

P0544 — Exhaust Gas Temperature Sensor Circuit Bank 1 Sensor 1 — 6.4 Power Stroke

Diagnostic reference for P0544 on 2008-2010 6.4L Power Stroke.

Updated October 15, 2026

What it means

Generic definition: PCM detected a fault in the bank 1 sensor 1 exhaust gas temperature sensor circuit. On the 6.4L, EGT sensors around the DOC/DPF are used for regeneration control.1

Most likely causes

  1. EGT sensor 1 (bank 1 sensor 1) internal failure or out-of-range resistance — Open or erratic thermistor changes the voltage seen by the PCM, setting a circuit fault for the sensor used in regen control.12
  2. Connector or harness heat damage near the exhaust/DOC/DPF — High under-hood and exhaust heat degrades the EGT 1 connector and wiring, causing intermittent opens or shorts that the PCM flags as a circuit fault.123
  3. Chafed or melted wiring between the EGT sensor and PCM — Routing near hot exhaust components can cause insulation failure and intermittent circuit faults for the EGT signal.123
  4. PCM EGT input circuit fault — Internal PCM input issue for the EGT 1 circuit can set a circuit fault even with a good sensor and harness.1

How to diagnose

  1. Verify code P0544 is present and check for related EGT codes (e.g., P0546, P2032/P2033) that indicate high/low circuit conditions.
  2. Inspect EGT sensor 1 connector and harness for heat damage, corrosion, oil contamination, and proper seating near the exhaust/DOC/DPF.
  3. Perform a visual and tactile inspection of the wiring loom from the EGT sensor to the PCM for chafing, melting, or exposure to exhaust heat.
  4. Check freeze-frame data for engine conditions when the fault set (regen active, high exhaust temps) to correlate with thermal stress on the circuit.
  5. If available, compare EGT readings from adjacent sensors during a controlled regen event to identify an implausible sensor 1 value versus expected DOC/DPF temperatures.

Parts and tools you may need

Tools you’ll need

Rough cost and difficulty

Likely repairPartsShop laborWho usually does it
Wiring or connector repair$10–$1001–4 hrsDIY with tools and a manual
Exhaust gas temperature sensor$50–$2500.5–1.5 hrsDIY with tools and a manual
Engine wiring harness section$100–$5002–5 hrsShop
ECM/PCM replacement (programmed)$600–$2,0001–3 hrsShop

Typical US independent-shop figures; labor runs about $120–$180 per hour (dealers charge more). Confirm the diagnosis before buying parts.

When to see a pro

If diagnosis points to PCM internal fault, high-pressure fuel system work, or requires exhaust disassembly, have a qualified diesel technician perform the work. Do not service high-pressure fuel or exhaust components while hot. If the vehicle enters limp mode or shows signs of DPF restriction, seek prompt professional diagnosis.

Check for recalls

Recalls are tied to your truck’s VIN, so check yours directly: enter the VIN at NHTSA’s recall lookup. Open safety recalls are repaired free at a dealer.

Sources

  1. Curated DTC seed — 6.4 Power Stroke (curated) ↩︎ ↩︎ ↩︎ ↩︎ ↩︎

  2. Curated DTC seed — 6.4 Power Stroke (curated) ↩︎ ↩︎ ↩︎

  3. Curated DTC seed — 6.4 Power Stroke (curated) ↩︎ ↩︎