P0667 — PCM/ECM/TCM Internal Temperature Sensor Range/Performance

P0667 — PCM/ECM/TCM Internal Temperature Sensor Range/Performance. A fault in the sensor and actuator circuits. The car is usually drivable while you plan the repair. Typical causes: control module driver fault, faulty sensor or actuator of the affected circuit, poor ground connection.

powertrain (engine/transmission)

Is it safe to drive?

Short-term driving is OK In most cases the car remains drivable, possibly with reduced performance or a disabled auxiliary system. If symptoms include stalling, no-start or brake/steering warnings, treat it as urgent.

How to diagnose with an OBD scanner

Read the code and freeze frame Connect an OBD2 scanner, confirm P0667 is stored, and save the freeze frame data — it shows engine conditions when the fault was detected.
Check for companion codes and TSBs Related codes often reveal the real root cause. Also check manufacturer technical service bulletins (TSB) for your make and model — many P0xxx issues have factory fixes or software updates. Search by VIN on the manufacturer site or nhtsa.gov.
Inspect wiring and connectors Visually inspect the wiring harness and connectors related to the PCM/ECM/TCM internal temperature sensor for damage, corrosion, chafing or poor contact.
Subsystem check Compare the PCM/ECM/TCM internal temperature sensor live reading against a known-good reference (specification or a correlated sensor) under the conditions from the freeze frame.
Subsystem check Measure reference voltage, ground and signal continuity at the component connector.
Subsystem check Wiggle-test the harness while watching the signal in live data — dropouts reveal broken wires.
Verify the repair Clear the code, complete a full drive cycle including the conditions from the freeze frame, and confirm P0667 does not return.

Approximate repair cost

Repair cost depends on which component actually failed. Typical scenarios for P0667 (parts and labor, USD, independent shop rates): Control module repair: $300–$1,000; Replace the faulty sensor or actuator: $150–$500; Repair wiring or connectors: $80–$250. Overall, fixing P0667 usually costs between $80 and $1,000. An accurate diagnosis before buying parts saves money — the most expensive scenario is rarely the first one to check.

Common questions

What are the symptoms of P0667?

Drivers most often notice: increased fuel consumption in some cases, Check Engine Light on, possible limp mode depending on the affected component, the affected system operates intermittently or not at all.

What does OBD2 code P0667 mean?

How do I diagnose P0667 myself?

Start with a scan: confirm P0667, save the freeze frame and note any companion codes. Then inspect the wiring and connectors related to the PCM/ECM/TCM internal temperature sensor, and verify the suspect component against live data before buying parts.

What is the most common cause of P0667?

The most common causes are: control module driver fault, faulty sensor or actuator of the affected circuit, poor ground connection.

Will P0667 clear itself?

Sometimes P0667 clears after a few drive cycles if the fault was intermittent — for example a loose connector or a tank of bad fuel. The underlying cause usually remains, so the code tends to return. Clear it once; if it comes back, diagnose rather than erase it repeatedly.

When your scan tool flashes P0667, the powertrain control module is telling you it has detected a problem with one of its own internal temperature sensors. The official description reads "PCM/ECM/TCM Internal Temperature Sensor Range/Performance," which places this fault squarely in the powertrain category — affecting either the engine computer, the transmission control unit, or a combined module depending on your vehicle's architecture.

The "range/performance" label is the key phrase here. It means the sensor is still producing an electrical signal that falls within measurable bounds, yet that signal does not align with what the control module expects given the current operating conditions. Unlike a "circuit short" or "circuit open" code, P0667 indicates the wiring itself is likely intact and conducting properly. The issue lies deeper — either the sensor element has drifted out of spec, the control module's signal-processing circuitry is faulty, or an unrelated mechanical problem is generating enough heat to confuse the sensor. The control module will not trigger this code from a single anomalous reading. It logs the fault only after observing the same out-of-range condition persist across multiple test cycles under specific temperature and load parameters. This is why the freeze frame data stored alongside P0667 is so valuable — it pinpoints the exact engine speed, load, temperature, and vehicle speed present when the fault first appeared, giving you a target to replicate during diagnosis.

Common Symptoms of P0667

The Check Engine Light is the most obvious indicator that P0667 has been stored, and it typically appears during the drive cycle that exposes the underlying condition. Depending on which internal sensor is affected and how severely it has drifted, you may notice the affected system behaving erratically or failing to operate entirely. Some vehicles will enter a reduced-power limp mode to protect themselves, particularly if the compromised sensor relates to transmission function. Fuel economy can climb upward in certain cases, though this varies by make and model. In mild instances, the car may feel completely normal aside from the illuminated warning lamp — the problem exists but has not yet triggered protective measures.

What Causes P0667

The root cause of P0667 can originate from several points in the signal chain. A degraded or drifting internal temperature sensor inside the control module itself is among the most common culprits. Poor ground connections at the module can introduce voltage offsets that the sensor interprets as temperature anomalies. A blown fuse feeding the relevant circuit starves the sensor of proper operating voltage. Corroded, loose, or physically damaged connectors interrupt the signal path even if the wires remain intact. Control module driver faults — where the electronics responsible for interpreting sensor input begin to fail — can also generate this code. Open or shorted wiring elsewhere in the circuit creates signal corruption that the module flags as a range violation. After a module software update or a battery disconnect/reconnect, incorrect calibration data may cause the module to expect sensor values outside the actual operating window. Finally, a mechanical fault somewhere in the system — such as an overheating component the sensor correctly detects — can also trigger the code when the module interprets the resulting temperature spike as a sensor malfunction rather than a legitimate reading.

How to Diagnose P0667

Effective diagnosis of P0667 follows a logical progression from data review to targeted testing. Begin by connecting a quality OBD2 scanner and confirming P0667 is stored in the module's memory. Before clearing anything, record the freeze frame data — this snapshot of engine load, rpm, coolant temperature, vehicle speed, and other parameters tells you precisely which conditions triggered the fault, allowing you to recreate them during testing. Next, scan for any additional trouble codes; related codes often share a common root cause and pointing toward the real problem. Consult manufacturer technical service bulletins for your specific make, model, and year — many P0xxx codes have documented factory fixes, updated calibrations, or known issues referenced by TSB number. Perform a thorough visual inspection of all wiring harnesses and connectors associated with the internal temperature sensor circuit, looking for chafed insulation, corrosion buildup, bent pins, or loose fits. With the engine running under the freeze frame conditions, compare the live internal temperature sensor reading against a known-good correlated sensor or the manufacturer's published specification to identify any meaningful deviation. Use a multimeter to verify reference voltage, ground integrity, and signal continuity at the component connector. Perform a wiggle test on the harness while monitoring live data — any signal dropouts or erratic readings reveal intermittent wire breaks. Finally, clear the code, complete a drive cycle that reproduces the freeze frame conditions, and verify P0667 does not return.

Repair Options and Costs

Repair strategy depends entirely on which component the diagnostic process identifies as the source. When the fault traces to damaged wiring or corroded connectors, repair or replacement typically runs $80 to $250 depending on labor time and connector availability. If testing reveals a faulty sensor or actuator within the circuit, parts and installation generally cost between $150 and $500. In cases where the control module itself has failed — confirmed through module-level testing — repair or replacement ranges from $300 to $1,000. Always address the cheapest probable causes first before committing to expensive module work.

How Much Does Fixing P0667 Cost?

The total bill for P0667 varies significantly based on what component is actually at fault. At the low end, wiring harness repairs or connector replacements at an independent shop typically cost between $80 and $250 including parts and labor. Sensor or actuator replacement generally falls in the $150 to $500 range. When the powertrain control module requires repair or replacement, expect to pay between $300 and $1,000. Most vehicles fall somewhere between the lowest and highest figures, and an accurate diagnosis before purchasing parts is the single best way to avoid overspending on unnecessary repairs.

Can You Drive with P0667?

In most driving scenarios, the vehicle remains operational after P0667 sets, though you may experience reduced performance, poorer fuel economy, or intermittent operation of an affected system. Extreme cases may trigger limp-home mode, limiting speed and power to protect drivetrain components. However, if the vehicle exhibits stalling, failure to start, or warnings related to braking or steering, treat the situation as urgent and seek repair immediately.