P0667
UniversalPCM / ECM / TCM Internal Temperature Sensor Range/Performance
Medium SeverityThe P0667 code indicates that the internal temperature sensor within the Powertrain Control Module (PCM), Engine Control Module (ECM), or Transmission Control Module (TCM) is reporting implausible data or is out of its normal operating range. This prevents the module from accurately monitoring its own internal temperature, which can affect its performance and lead to incorrect operation of other vehicle systems.
⚠️ Before You Begin (Safety First)
Always exercise caution when working with vehicle electronics. Before performing any diagnostics or repairs, ensure the vehicle is turned off, the parking brake is engaged, and for safety, disconnect the negative battery terminal to prevent accidental shorts or electrical shocks. Avoid working on a hot engine or transmission.
Common Symptoms
- Check Engine Light (CEL) illuminated
- Engine performance problems (rough idle, misfires)
- Transmission shifting issues (hard shifts, delayed engagement)
- Vehicle entering 'limp mode'
- Other warning lights on the dashboard
Common Causes
- Faulty internal temperature sensor within the PCM, ECM, or TCM
- Internal circuit board failure within the control module
- Software glitch or corruption within the control module
- Less commonly, a wiring issue affecting the module's power or ground, causing it to report incorrect internal data
Frequently reported on: General/Universal
Diagnostic Steps
- Scan for additional diagnostic trouble codes (DTCs) to identify any related issues.
- Perform a visual inspection of the PCM/ECM/TCM and its wiring harness for any obvious signs of damage, corrosion, or loose connections. Ensure connectors are fully seated.
- Clear the P0667 code and test drive the vehicle to see if the code returns.
- If the code persists, and no external wiring issues are found, the fault is likely internal to the control module, which generally requires professional diagnosis or replacement.
👨🔧 When to Call a Professional
This code points to an internal issue within a critical control module. While basic checks can be performed by a DIYer, precise diagnosis often requires specialized scanning tools and knowledge to interpret internal module data. If you lack experience with advanced diagnostics or module replacement, it is highly recommended to consult a professional technician. Incorrectly diagnosing or replacing control modules can lead to further vehicle issues.
Commonly Asked Questions
What does P0667 specifically mean for my car?
P0667 indicates a problem with the internal temperature sensor of your car's main computer (PCM, ECM, or TCM), meaning the computer can't accurately monitor its own operating temperature. This can lead to the computer not functioning correctly.
Can I drive with a P0667 code?
While you might be able to drive, it's not recommended for long periods. The internal module temperature affects its performance, and continued driving could lead to erratic vehicle behavior, increased wear on components, or even permanent damage to the module itself.
How is P0667 diagnosed?
Diagnosis typically involves using an advanced scan tool to monitor live data from the control module, checking for implausible temperature readings. A professional might also perform voltage and ground checks at the module connector and, in some cases, internal module testing if equipped.
What are the common repairs for P0667?
The most common repair is the replacement or, in some specialized cases, repair/reflashing of the affected control module (PCM, ECM, or TCM). Less commonly, if external wiring causes the issue, a wiring repair might be needed.
Is fixing P0667 expensive?
Repairing P0667 can be costly as it often involves replacing a major control module, which can be an expensive part and may require programming or coding to your vehicle after installation. Labor costs for diagnosis and replacement also contribute to the overall expense.