7 posts · Joined 2010. #1 · Jan 26, 2011. I just received diagnostic code P0128 while driving home. From my search I understand it is an issue with the thermostat or coolant. Which makes sense as the following has played out in the last few days: 4 days ago I noticed my coolant level was about a half inch below the minimum line on the …The most common symptom of a P0128 trouble code in a Jeep Renegade is an illuminated malfunction indicator lamp (MIL). Other symptoms may include poor engine performance and a decrease in fuel economy. Lack of heat– The most prominent symptom of the P0128 trouble code in the Jeep Renegade is the lack of heat. When the …The P0128 code is set when the engine control module (ECM) determines that coolant temperature is lower than the original equipment thermostat’s opening temperature. In this mode, when everything is warmed up, the ECM begins to use the oxygen sensor(s) for fuel control.I dropped off my Renegade for this issue and my first oil change (mileage 4601). I picked up this morning at 10 am, paperwork states malfunction indicator lamp is on, found fault code P0128 logged indicating an issue detected in the thermostat system. Performed software upgrade on the PCM per TSB# 18-061-16.P0401: Faulty EGR (Exhaust Gas Recirculation) valve. P0455, P0446, P0442, P0440, or P0411: Problem with the evaporative system. P0305 or P0300: Engine misfires. P0175 or P0171: Faulty oxygen sensor. While these are the most common codes that the 7E8 engine code menu shows, they aren’t the only ones that the menu can have.P0128 is a generic powertrain code that means the engine control module (ECM) detected that the motor hadn’t reached its required operating temperature within the required timeframe set by the …Jan 31, 2021 · Code P0128 came up and he told me he would need to replace the thermostat and housing since there were cracks and coolant was seeping. I tried reading up on the issue and watched some YouTube videos on how to replace so I am debating whether I should try to do the job myself or leave it to the mechanic. HI @Jonathan, The P0128 code is very common. Your Cherokee's computer knows how long it should take for the car to warm up. Using the sensors that measure the air temp (ambient) as well as the temperature of the coolant, if the computer finds a deviation from what it expects or the value is completely out of bounds from what it should be (rationality), it illuminates the CEL and saves a P0128 ...HI @Jonathan, The P0128 code is very common. Your Cherokee's computer knows how long it should take for the car to warm up. Using the sensors that measure the air temp (ambient) as well as the temperature of the coolant, if the computer finds a deviation from what it expects or the value is completely out of bounds from what it should be (rationality), it illuminates the CEL and saves a P0128 ...P0128 code. Jump to Latest ... If this is the 3.6 engine, it is designed for the engine operating temp from cold start to reach 160 degrees, within 20 minutes of driving time. If it doesn’t reach that temp, then it will throw this code. ... A forum community dedicated to Jeep Wrangler owners and enthusiasts. Come join the ...Nov 10, 2021 · Your engine would not get up to full operating temp, and clearly the code P0128 is likely as well as others. Now, the description of P0128 is the engine takes too long to warm-up. Its an emissions requirement, because the engine makes more emissions while its cold, so the Federal Gov mandates it has to warm-up within a certain amount of time. 447 posts · Joined 2016. #2 · Jan 23, 2017. That code is usually displayed when the engine takes too long to reach operating temperature (thermostat stuck open). So, under certain conditions after you clear the code, depending on outside air temp, driving conditions, it may warm up within the parameters the computer is looking for, despite ...When your robust Jeep Patriot winks at you with the p0128 code, it's essentially complaining about the coolant thermostat temperature. Let’s crack on and delve deeper into this mystery. If this OBD II trouble code flashes for the Jeep Patriot, it's a sign that the engine's coolant isn't warming up as quickly as it should after ignition.Follow up to the original question. My CEL has been on for a few days. Finally scanned last night and got the same code P0128. Coolant was pretty low, but not below the add line. I went ahead and topped off the coolant. Was hoping that's the simple fix before replacing the thermostat. The jeep is running fine, all the temperatures seem normal.The trouble code is generated by the engine coo... My 2016 Jeep Wrangler JKU has been throwing up the CEL with a P0128 Code off and on during the winter months. The trouble code is generated by ...P0128-THERMOSTAT RATIONALITY. For a complete wiring diagram, refer to the Wiring Information. When Monitored and Set Conditions. This diagnostic runs when the following conditions are met: With the engine running. Start up coolant temperature less than 65°C (149°F).Low or weaker coolant levels can trigger the P0128 code in your Jeep Grand Cherokee because it can alter the engine running temperature, causing it to deviate from its ideal operating temperature. This can be detected by the engine coolant temperature sensor, which sends signals to the engine computer (PCM) about the engine’s temperature.Code P0128 came up and he told me he would need to replace the thermostat and housing since there were cracks and coolant was seeping. I tried reading up on the issue and watched some YouTube videos on how to replace so I am debating whether I should try to do the job myself or leave it to the mechanic.2016, 3.6 Check Engine light P0128 coolant temp code. ... A forum community dedicated to Jeep Wrangler owners and enthusiasts. Come join the discussion about reviews, performance, trail riding, gear, suspension, tires, classifieds, troubleshooting, maintenance, for all JL, JT, JK, TJ, YJ, and CJ models! ...=====Claim your FREE engine code eraser 👉 https://free.nonda.co 👈=====Engine Code P0128 Saving Repair Part...P0128-THERMOSTAT RATIONALITY. For a complete wiring diagram, refer to the Wiring Information. When Monitored and Set Conditions. This diagnostic runs when the following conditions are met: With the engine running. Start up coolant temperature less than 65°C (149°F).Oct 28, 2023 · How to Diagnose P0128 Thermostat Issues on a Jeep? When your Jeep has a P0128 code, use these steps to diagnose the root cause: Use an OBD2 Scanner Tool. Plug in a diagnostic scan tool to pull the P0128 code and any other related trouble codes from the engine control module (ECM). This will confirm the issue is a faulty thermostat regulation one. I have a 1999 jeep grand cherokee limited 4.7l v8 4wheel drive. i haveHow i solved my jeep's p0456 check engine light code (jeep grand 6 4 hemi srt jeep engine oilCherokee jeep grand engine light check 2004. Check Details Jeep …c.d.c. This code sets when the ECM sees that the engine takes to long to warm up. This usually happens because the thermostat is either stuck open or opening sooner than it should. It is a pretty global cause and correction for P0128 across many makes and models of vehicles. Replacing the T-stat should take care of this and you should not have ...Before getting into in-depth knowledge about the P0128 Code, first of all, know what does a P0128 means and how it works in your car. Don’t worry we are here to explain how long can you drive with a P0128 code. P0128 is telling your fix sensor that your car’s coolant thermostat is operating below the regulating temperature.9 Oct 2023 ... 2014 Jeep Wrangler sport unlimited 4x4 changing those things should get rid of a check engine code p0128 code "coolant temp below ...Don't procrastinate on fixing misfires as they can quickly damage catalytics. as for your p0128, it was likely a history code (unless your check engine was on solid. p0128 will only reset after quite a few cycles (believe 40 from history). No worries as if it did set once, your thermostat was likely losing some performance.The check engine light on the dash of the 91 to 96 Jeep Cherokees displays ECU codes, which can be accessed by looking at the light. On and off the key repeatedly, but never starting the Jeep. Take a moment to count the flashes and note the pause between them. A 12 is usually used as the first code.What year did the Jeep Grand Cherokee have the 3.6L engine? The 3.6-liter engine was introduced in the 2011 Jeep Grand Cherokee models and was available through the 2015 models. What causes the P0128 code on a Jeep Grand Cherokee? The most common cause for the P0128 code on a Jeep Grand Cherokee is a faulty thermostat.P0128 Thermostat Rationality - With the engine running, start up coolant temperature less than 65°C (149°F), ambient temperature between -8°C (17.6°F) and 50°C (122°F), avarage vehicle speed greater than 16 km/h (10 mph) until coolant temperature reaches 85°C, engine speed does not go above 5400 rpm for more than 32 seconds, …Aug 22, 2018 · trailhunter. 1858 posts · Joined 2013. #2 · Aug 22, 2018. From the internet. There are two main*causes*for*P0128: The most common*cause*is an engine coolant thermostat that has stuck open or is opening prematurely. The next*cause*is a problem with the engine coolant temperature sensor or the wiring associated with the sensor. The P0128 code is triggered when the engine control module (ECM) detects the engine coolant temperature (ECT) below the thermostat regulating temperature. This can be caused by several factors, including: A Faulty Engine Coolant Thermostat.9 Oct 2023 ... 2014 Jeep Wrangler sport unlimited 4x4 changing those things should get rid of a check engine code p0128 code "coolant temp below ...Indian children are playing catch up with the rest of the world. Outside India, one in three kids typically begin learning to code before they turn 15. In India, only one in 10 do....Watch as I replace the thermostat on my 2015 Jeep Wrangler Unlimited after getting the P0128 Error Code.Nov 6, 2018 · The most common symptom of a P0128 trouble code in a Jeep Grand Cherokee is an illuminated malfunction indicator lamp (MIL). Other symptoms may include poor engine performance and a decrease in fuel economy. Lack of heat– The most prominent symptom of the P0128 trouble code in the Jeep Grand Cherokee is the lack of heat. When the thermostat ... Jun 14, 2020 · Indicates that the thermostat monitor has not achieved the required engine operating temperature within a specified amount of time after starting the engine. P0128 Jeep Code - Thermostat Rationality. 13 Nov 2021 ... The infamous check engine light came on in my Jeep. I immediately ran a scan on the JK to see what the problem is and the JScan displayed a ...tmoca Discussion starter. 77 posts · Joined 2010. #1 · Oct 27, 2021. Okay, so my engine light came on today. Stopped by the auto parts store to have the code checked. Came back P0128 stating coolant temp below regular temp. So the guy suggested a thermostat said it is quite common. I also snagged some coolant to top it off, because I know I ...P0128 code. Jump to Latest ... If this is the 3.6 engine, it is designed for the engine operating temp from cold start to reach 160 degrees, within 20 minutes of driving time. If it doesn’t reach that temp, then it will throw this code. ... A forum community dedicated to Jeep Wrangler owners and enthusiasts. Come join the ...May 11, 2023 · The P0128 code indicates an issue with your engine coolant temperature. If left untreated, this can lead to decreased fuel efficiency, reduced engine performance, and even engine damage. What causes the P0128 code? The P0128 code can be caused by several factors, including a faulty thermostat, a low engine coolant level, a malfunctioning engine ... P0128 Code: Causes of Low Coolant Regulating Temperature in your Jeep Wrangler The OBD-II trouble code P0128 has much to do with the engine’s operating temperature. When the ECM detects anomalies in the engine coolant temperatures, that is where the problem lies.9 Feb 2023 ... Walk through the steps for replacing a thermostat and housing. Once that is done follow up with bleeding the air out of the system.What is the Cost to Diagnose the Code? Labor: 1.0. The cost to diagnose the P0118 Jeep code is 1.0 hour of labor. The diagnosis time and labor rates at auto repair shops vary depending on the location, make and model of the vehicle, and even the engine type. Most auto repair shops charge between $75 and $150 per hour.P0128-THERMOSTAT RATIONALITY. Theory of Operation. The PCM predicts what the engine coolant temperature should be, based on the engine coolant temperature at start-up, ambient temperature and how the vehicle is subsequently driven. The predicted engine coolant temperature is compared to the Engine Coolant Temperature Sensor reading.2017 Jeep Renegade OBDII Code P0128 - Coolant Temperatore Below Thermostat Regulating temperature Weather during readings - Sunny, 38F outside Weather during first check engine light appearance - Sunny, 34F outside I am trying to diagnose the exact cause of the issue at present.The code P0128 - Coolant Temperature Below Thermostat Regulating Temperature means that the engine does not reach expected temperature after running for sufficient time, or in other words, it takes …i was just driving about 10 minutes ago and my engine light came on, and the code was P0128-THERMOSTAT RATIONALITY, my mods are intake, 3 in. SEE no cat, and motor mounts, im just stumped what this code means, any help would be great! ... This code means that the engine did not warm up to 180 in 10 minutes after startup. This is a ...The P0128 OBD-II trouble code is a generic powertrain diagnostic code (it has the same meaning for the Jeep Patriot as any other vehicle). Coolant Temperature The coolant temp sensor is responsible for telling the Engine Control Module (ECM) the engine’s coolant temperature.Before getting into in-depth knowledge about the P0128 Code, first of all, know what does a P0128 means and how it works in your car. Don’t worry we are here to explain how long can you drive with a P0128 code. P0128 is telling your fix sensor that your car’s coolant thermostat is operating below the regulating temperature.The P0128 code in your 2014 Jeep Grand Cherokee indicates a potential issue with the engine coolant temperature (ECT) sensor or thermostat. To diagnose the cause, you can perform the following steps: 1. Start by checking the coolant level and make sure it is at the proper level. 2.For the first time that I can recall Rubi started throwing an error code. After several months I decided to fix it. Originally I was told it was the cooling ... Check Engine Light P0128 error code - 2013 Jeep Grand Cherokee (WK2) - thermostat replacementStep by step how to. My Jeep Grand Cherokee's check engine light...