P0667 code definition
The P0667 code identifies a problem with a temperature reading within the engine or transmission.
The P0667 code is often associated with the P0668 code.
What the P0667 code means
P0667 is the OBD-II generic code for a fault involving the internal temperature of the engine or transmission. In some applications, there are separate control modules for the engine and transmission, both with their own temperature sensors and circuitry. In other applications, the powertrain control module receives signals from the temperature sensors in the engine and transmission. If these sensors sense a temperature that is above the manufacturer's specifications, a code will be stored by the OBD-II system immediately.
What causes the P0667 code?
The P0667 code has a number of common causes:
- Overheating in the engine
- Overheating in the transmission
- Faulty temperature sensor in the engine or transmission
- Faulty wiring in the temperature sensor circuits
What are the symptoms of the P0667 code?
When the P0667 code appears, the Check Engine light will illuminate on the dashboard. Since this issue usually occurs deep within the engine or transmission, there will not be many external symptoms. There may be sputtering or lack or power, assuming the engine stays running. This fault does have the ability to stop the engine and prevent it from starting up again.
How does a mechanic diagnose the P0667 code?
Due to the serious nature of the P0667 code, the affected circuit will have to be tested by a qualified technician with a voltmeter before further diagnostic work can take place. Once that has taken place, the technician will use an OBD-II code scanner that is capable of seeing the factory readings to view the fault and at what time the fault appeared. Once this information is viewed, the code will be reset and the car will be taken for a test drive.
If, during the test drive, the fault does not appear again, then it can be assumed that the fault was initially caused by a short or other issue within the wiring of the affected sensor or control module. While this is a problem, it is not as serious as excessive temperature in the engine or transmission.
The wiring and the circuitry surrounding the affected circuits, sensors, and control modules will be thoroughly inspected for damage or shorts in the circuit. Loose wires or connectors will be repaired or replaced.
Common mistakes when diagnosing the P0667 code
Due to the limited number of causes that can make the P0667 appear, there are not many mistakes that can take place in the diagnosis. Either there is a serious temperature problem within the engine or transmission, or there is a problem with the sensors and wiring. No parts should be repaired or replaced before the circuitry and wiring surrounding the affected sensor is inspected.
How serious is the P0667 code?
The P0667 code is an indicator of a serious problem within the engine or transmission. This fault may cause the engine to stop and may also cause the engine the be unable to start again one it has stopped. If the engine does not stop of its own accord, it should be shut off as soon as it is possible to do so safely. A qualified technician should then be contacted to assist with the P0667 code.
What repairs can fix the P0667 code?
The most common repairs to address the P0667 code are as follows:
- Replace faulty wiring harness
- Repair or replace damaged sensor circuits
- Replace faulty powertrain control module
- Replace faulty engine control module
- Replace faulty transmission control module
- Replace or rebuild vehicle transmission
- Replace or rebuild vehicle engine
Additional comments for consideration regarding the P0667 code
While this is a serious code and can precede catastrophic damage to the drivetrain, it is most often the result of faulty wiring or other electrical issues.
Need help with a P0667 code?
YourMechanic offers certified mobile mechanics who will come to your home or office to diagnose and repair your vehicle. Get a quote and book an appointment online or speak to a service advisor at 1-800-701-6230.
This article originally appeared on YourMechanic.com as P0667 OBD-II Trouble Code: PCM/ECM/TCM Internal Temperature Sensor Range or Performance and was authored by Ian Swan.