Thermostat Function
Table of contents
- Possible Causes
- How To Fix
- Tech Notes
- Cost To Diagnose
- When is the code detected
- Possible Symptoms
- Description
P0128 NISSAN Possible Causes
- Leaking or stuck open thermostat
- Low engine coolant level
- Insufficient warm up time
- Faulty engine coolant temperature sensor
- Engine coolant temperature sensor harness is open or shorted
- Engine coolant temperature sensor circuit poor electrical connection
How do I fix code P0128 NISSAN?
Check the “Possible Causes” listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector’s pins.
Tech Notes
- If the cooling system is not leaking and the fluid level is OK, replacing the thermostat usually takes care of the problem.
- There is a factory service bulletin for all Nissan Models 2002 and Up, with the P0128 and remote starter system. Bulletin information:
- IF CONFIRM
- The MIL is “ON” with P0128 (Thermostat Function) stored.
- ACTIONS
- 1. Check to see if an aftermarket remote starter system is installed. Remote starter systems may cause the MIL to illuminate and DTC P0128 to store.
- 2. If a remote starter system is installed, remove/disconnect it before performing diagnostic procedures on the vehicle.
Cost of diagnosing the P0128 NISSAN code
The cost of diagnosing the P0128 NISSAN code is 1.0 hour of labor. The auto repair labor rates vary by location, your vehicle’s make and model, and even your engine type. Most auto repairs shops charge between $75 and $150 per hour.
When is the code detected
The engine coolant temperature does not reach to specified temperature even though the engine has run long enough.
Possible Symptoms
- Engine Light ON (or Service Engine Soon Warning Light)
P0128 NISSAN Description
The thermostat is a component that blocks the flow of coolant to the radiator until the engine has warmed up. When the engine is cold, no coolant flows through the engine. Once the engine reaches its operating temperature, the thermostat opens. The OBDII sets when the engine coolant temperature has not risen enough to open the thermostat even though the engine has run long enough. This is due to a leak in the seal or the thermostat open stuck.