Location: Arkansaw. Posts: 54. p0641. Ok, so I'm having trouble with a p0641 code that is also throwing codes for each sensor on that 5v reference circuit. I did a cam swap about a year ago and haven't driven the car just a whole lot, but have put several thousand miles on it and have done an oil change. BTR stage 4, putting down about 472 …The P0641 slowly drained my battery from 12.7 volt to 7 volt in a week. The good news, I found schematic & localized the issue. The voltage on exhaust camshaft position sensor, intake camshaft position sensor and fuel tank pressure sensor is too high - 11.9v.The expansion for a P0641 code on the Chevrolet Impala is Sensor Reference Voltage "A" Circuit Open. Was that as clear as mud OK, so what it's saying is that the powertrain control module (PCM) basically supplies a reference voltage to the various onboard sensors (the same way a desktop computer does to its ports) at, say, 5 volts. The sensors verify this voltage signal in reference to ...OBD II fault code P0641 is a generic code that is defined as “Sensor reference voltage “A” -circuit open”, and is set when the PCM (Powertrain Control Module) detects an open circuit in the “A” reference voltage …B0000 – Body Code. C0000 – Chassis Code. U0000 – Network Code. Conclusion. In conclusion, the P0641 code is a diagnostic trouble code that refers to a problem with the voltage output from the sensor reference voltage A circuit. The code is set when the ECM/PCM detects an open or short in the sensor reference voltage A circuit.26 Feb 2022 ... Hello in this video I hope to help you diagnose your car if you have all of the same codes I have. Also I failed to mention my map sensor ...Apr 22, 2010 · smokester said: I think I found the real problem. The Troubleshooting chart I have for the code P0641 said to disconnect the Fuel Rail Pressure (FRP) sensor and then check the reference voltage at the Accelerator Pedal Position sensor (APP). I did that and nothing changed, still low voltage. The currently selected ODB-ii codes is for the Acura makes. 2. Look up the other OBD II Trouble Codes, please use the search box. Enter the 5 character trouble codes in the search box and submit the search. 3. Don’t assume a particular OBD-II code means the same for other auto manufacturers as there are many makes specific codes in use. 4.Code P0641 stands for Sensor Reference Voltage 'A' Circuit Open. In the event of a sensor reference “A” malfunction, a trouble code will be stored and a service engine soon lamp may be illuminated. PCM supplies a reference voltage to many of the onboard sensors. Typically, this reference signal is 5-Volts. The sensors then verify this ...17 Jul 2022 ... What are the Possible Causes of the DTC P0641 2014 Chevrolet Silverado? · Faulty Sensor on 5 Volt circuit · Sensor on 5 Volt circuit harness is ....The cost to diagnose the P0641 2015 Chevrolet Silverado 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.Multiple codes but only returning hard faults are p0641,p0651, p0697, p06a3, p2230, p262b. reference voltage 1 thru 4 on scanner … read more. Jared D. Shop Supervisor. Bachelor's. 2,522 satisfied customers. P0641 code in my 2008 Chevy Silverado. The motor goes in. P0641 code in my 2008 Chevy Silverado .30 Jul 2023 ... p0641 5 volt reference 1 circuit 5 volt reference short to ground.That is why I was asking if the pedal sensor would throw a P0641 Code. Reference Circut 1. Chevy Mechanic: Tim's Auto Repair. yes, it could be the pedal sensor. Ask Your Own Chevy Question. Chevy Mechanic: Tim's Auto Repair. also another thing the hard jar may have effected is the fuel pump pressure control module.When the PCM detects an open circuit in the ‘A’ reference voltage circuit, it stores the P0641 code and may trigger the check engine light on your Chevy Trailblazer. Keep in mind that the P0641 code is a generic trouble code, which means it applies to all model years of the Chevy Trailblazer built after for the 1996 model year and up.The video shows how I found a chafing point on the engine harness that was causing a P0641 5 volt reference 1 short to ground fault.It’s triggered when the PCM detects voltage that doesn’t match manufacturer specifications on the 5-volt reference circuit. Code P0641 is typically caused by malfunctioning sensors, wiring issues, and PCM problems. The most common symptoms of P0641 include a lit check engine light and sensor issues. Contents.P0641 Definition: Sensor Reference Voltage “A” Open. When you encounter the P0641 code on your Chevy Equinox, it signifies an issue with the sensor reference voltage ‘A’ circuit.Aug 21, 2019 · 1727 posts · Joined 2016. #2 · Aug 23, 2019. A bunch of sensors are all connected via the CAN bus system. The generic code p0641 means there's a problem somewhere in that circuit, but it doesn't really pin point the specific sensor. The problem could be anywhere along the line, including the ECU. In this repair video we go thru identifying the cause of both a P0641 and C0561 diagnostic trouble code (DTC) being present, along with _SERVICE TRACTION_ an...Chevy 2009 Cobolt. My fault code is p0641. along with a reduced power indication from odometer led display. Really confused on this one. in looking up the sensors attached to this 5v reference to ecm, … read moreAug 21, 2023 · When the PCM detects an open circuit in the ‘A’ reference voltage circuit, it stores the P0641 code and may trigger the check engine light on your Chevy Malibu. Keep in mind that the P0641 code is a generic trouble code, which means it applies to all model years of the Chevy Malibu built after for the 1996 model year and up. I agree that the P0641 is likely the main cause of the vehicle entering limp mode. There is a common problem with the wiring harness that goes back to the Fuel Tank Pressure Sensor to rub through on the front driveshaft causing this code. If this is the case, it could also be affecting the Fuel Level Sensor wiring causing the P0463.We would like to show you a description here but the site won’t allow us.2009 Suburban LT 4x4 5.3 Flex fuel engine. I swapped the ECM a few months ago due to a Po641 code and the truck not coming out of a limp-home mode. When that one happened it would show trouble codes f … read moreFeb 27, 2020 · nealinator. 18285 posts · Joined 2015. #2 · Feb 27, 2020. Some reading for you here: P0641 code. Could be a bad sensor or a wire issue (even just a plug disconnected. Have a look around for anything unplugged or and damaged wires. Nealinator's 5.3L 4x4 Z71 All Terrain. Borla Touring cat back exhaust - Bilstein 5100's front level - Zone AAL ... My son's 2009 chevy silverado with a 6.0 liter engine died and has the following trouble codes: P0121, P0230, P025A, P0449, P0452, P0521, P0641, & P069E … read more ExpertI have 2009 chevy sicerado 5.3 motor. I have codes p0106, p0108,p0340,p0641 ... it had a cam sensor code first and then - Answered by a verified Chevy Mechanic. By chatting and providing personal info, ... re-occurring code po121 on a chevy pick up 5.3 engine Not sure if I should change the throttle body or the electronic …2,567 satisfied customers. P0641 code in my 2008 Chevy Silverado. The motor goes in. P0641 code in my 2008 Chevy Silverado . The motor goes in limp mode. I also have code P0122,P0449,P0463. I think my main problem is 641. … read more. Alex. Automotive Technician.Step 3: Inspect sensors and wiring harness. Inspect all the sensors associated with the P0641 code, making sure to check for any visible damage, corrosion, or loose connections. Additionally, examine the wiring harness and connectors for signs of wear or disconnections, as these could also contribute to the problem.FIX CODE P0107 P0106 ENGINE LIGHT ON CHEVY, CHEVROLET, BUICK, GMC, CADILLAC Car Scanner: https://amzn.to/2tdNh5k Check out our Amazon Store for the tools a...14 Mar 2016 ... P0641 has been the common denominator of the recent issues of my '07 Cobalt with 2.2 L EcoTec engine. A year ago, it came up with an engine ... The automobile fault code P0651 indicates a problem with the Engine Control Module (ECM). Symptoms may include various electrical issues or a malfunctioning engine. The cause of this fault code can be a faulty ECM, an open or shorted ECM harness, poor electrical connections in the ECM circuit, or a shorted sensor on the 5-volt circuit. To fix ... That is why I was asking if the pedal sensor would throw a P0641 Code. Reference Circut 1. Chevy Mechanic: Tim's Auto Repair. yes, it could be the pedal sensor. Ask Your Own Chevy Question. Chevy Mechanic: Tim's Auto Repair. also another thing the hard jar may have effected is the fuel pump pressure control module.14 Nov 2015 ... The engine computer sends a 5 volt reference to most of the sensors on the car and what comes back to the computer is how it knows whats going ...This 2008 GMC Yukon came in with the complaint of reduced power and the vehicle could not be driven over about 35 mph. There were a lot of codes stored but the only one of real relevance was Code P0641 Symptom 00, 5 volt reference circuit 1. I looked at data under the TAC section of the PCM and found the circuit reading fluctuating between 0 ...The great American sports car is going electric. GM shared the news this morning, and released the first images of the upcoming electric Chevrolet Corvette. The great American spor...P0641-Engine power is reduced Camaro Issues / Problems | Warranty ... Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums - Camaro5.com > Technical Camaro Topics > Camaro Issues / Problems | Warranty Discussions | TSB and Recalls: P0641-Engine power is reduced ... Been getting this code for awhile now …11 Silverado 1500, been throwing a code where it cuts off power, and traction control and stabilitrak are shut off. I can shut off engine and let sit for 30 seconds and re fire and keep going with 0 issue. However it's happened about every 2nd or 3rd day for about 2 weeks now. Code reader shows po641 which is a 5 volt circuit reference. The automobile fault code P2227 indicates a problem with the barometric pressure circuit range or performance. The estimated repair time for this fault code is 1.0 hour. The cost of fixing this issue can vary depending on the auto repair shop, but it is common for most shops to charge between $75 and $150 per hour. 2,567 satisfied customers. P0641 code in my 2008 Chevy Silverado. The motor goes in. P0641 code in my 2008 Chevy Silverado . The motor goes in limp mode. I also have code P0122,P0449,P0463. I think my main problem is 641. … read more. Alex. Automotive Technician.When the PCM detects an open circuit in the ‘A’ reference voltage circuit, it stores the P0641 code and may trigger the check engine light on your Chevy Impala. Keep in mind that the P0641 code is a generic trouble code, which means it applies to all model years of the Chevy Impala built after for the 1996 model year and up.The trucks and SUVs made by Chevrolet and GMC are almost identical. GMC vehicles, however, cost more than Chevrolet vehicles because General Motors markets GMC vehicles as more pro...Feb 22, 2019 · I agree that the P0641 is likely the main cause of the vehicle entering limp mode. There is a common problem with the wiring harness that goes back to the Fuel Tank Pressure Sensor to rub through on the front driveshaft causing this code. If this is the case, it could also be affecting the Fuel Level Sensor wiring causing the P0463. When the PCM detects an open circuit in the ‘A’ reference voltage circuit, it stores the P0641 code and may trigger the check engine light on your Chevy HHR. Keep in mind that the P0641 code is a generic trouble code, which means it applies to all model years of the Chevy HHR built after for the 1996 model year and up.DTC P0641 5-Volt Reference 1 Circuit. Conditions for Running the DTC. • DTCs P0601, P0602, P0604, P0606, P1621, and P2610 are not set. • The ignition is in unlock, accessory, run, or crank mode. • The ignition voltage is greater than 5.2 volts. • DTC P0641 runs continuously when the above conditions are met.C6 Scan & Tune - Car throwing P0641 code - interpretation??? - My car went into reduced engine power mode recently so I pulled codes and it had one, P0641. My code reader interpretted it as Sensor A reference Voltage Circuit/Open . ... CorvetteForum - Chevrolet Corvette Forum Discussion; C6 Corvette, 2005 - 2013; C6 Scan & Tune; Car …P0641 5-volts reference 1 circuit. Yes one sensor can be shorting out causing reduce power, For the first inspection disconnect the ECM and inspect the pins for any corrosion or loose pin at its connection and terminal, The color for the 5 volt refernce is Grey/White. The camshaft is Dark blue.The APP is White/Black.When I find a stored P0641 code, it means that the powertrain control module (PCM) has detected an open circuit for a particular sensor; designated in this case as "A". When diagnosing an OBD-II code, the term open could be substituted for absent.Chevy impala ghost machine Chevy silverado p0741 obdii code diagnosis P0641 code Silverado p0741 quite trouble. Fix Engine; Po641 Chevy Silverado 23 Nov 2023. Chevy silverado p0446 obdii code diagnosis Silverado gmc z71 autotrader trims 16-na-102: duramax diesel hard start, no start, dtcs p0087, p0088 ...Repair Information for P0641 Chevrolet code. Learn what 5 Volt Reference 1 Circuit means, location and how to repair? The Engine Control Module (ECM) has four (4) internal 5 Volt reference circuits (Some models have two (2) internal 5 Volt reference circuits).Chevy 2009 Cobolt. My fault code is p0641. along with a reduced power indication from odometer led display. Really confused on this one. in looking up the sensors attached to this 5v reference to ecm, … read moreRepair Information for P0641 Chevrolet code. Learn what 5 Volt Reference 1 Circuit means, location and how to repair? The Engine Control Module (ECM) has four …GM may be replacing tens of thousands of Bolt EV batteries, but it won’t have to pick up the tab for most of them. The automaker has reached a deal that will have LG pay nearly all...Hello Everyone, I come here often for answers so I figured I would join the chat! Anyways I have a 2009 chevy Aveo LT.Aug 21, 2023 · When the PCM detects an open circuit in the ‘A’ reference voltage circuit, it stores the P0641 code and may trigger the check engine light on your Chevy Trailblazer. Keep in mind that the P0641 code is a generic trouble code, which means it applies to all model years of the Chevy Trailblazer built after for the 1996 model year and up. A P0641 code means that your Chevy Silverado’s Powertrain Control Module (PCM) has detected an issue with the 5-volt reference circuit voltage, which may be higher or lower than expected. This circuit feeds into multiple engine sensors such as the Engine Oil Pressure Sensor, the Fuel Rail Pressure Sensor, the A/C refrigerant pressure sensor ...Feb 17, 2016 · I'm having the same problem I have the codes p0641 p0643 and p0340. I have the reduced engine power warning service stabil track and I have the loss of oil pressure as well. I have checked voltage at the map sensor, tp sensor, op sensor and have around 4.82v to those ones. I checked the cam position sensor and no voltage at all. 3 posts · Joined 2022. #1 · Feb 25, 2022. Hey guys. I’m goin crazy here. Did head gaskets on my 2015 lml duramax cab off and got it back together and I’m getting a p0641 5v reference circuit 1 code and a p0193 frp I’ve tried unplugging everything on that circuit and still says fault. I’ve looked all over for something left unplugged ...The PCM monitors the voltage on the 5-volt reference circuit. If the PCM detects that the voltage is out of tolerance, DTC P0641 sets. The engine is running. - The PCM detects a voltage out of tolerance condition on the 5-volt reference circuit. - The above condition is present for longer than 2 seconds.I'm having the same problem I have the codes p0641 p0643 and p0340. I have the reduced engine power warning service stabil track and I have the loss of oil pressure as well. I have checked voltage at the map sensor, tp sensor, op sensor and have around 4.82v to those ones. I checked the cam position sensor and no voltage at all.Apr 22, 2010 · smokester said: I think I found the real problem. The Troubleshooting chart I have for the code P0641 said to disconnect the Fuel Rail Pressure (FRP) sensor and then check the reference voltage at the Accelerator Pedal Position sensor (APP). I did that and nothing changed, still low voltage. **Want to own the tools I use ?? Click on the amazon link below to get my top 5 Tools I use**Automotive Test Light- https://amzn.to/3z1PdxaFlexible Backprobe... Labor: 1.0. The cost to diagnose the P0641 2018 Chevrolet Silverado 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. Search for P0641 2018 Chevrolet Silverado ... DTC P0651, P0652, P0653, P0697, P0698, or P0699 should not be set. If a DTC is set, refer to DTC P0641-P0643, P0651-P0653, or P0697-P0699. Observe the scan tool APP Sensor voltage parameters. Verify both of the APP sensor voltages are …The P0641 code, one of the problems within the engine control module (ECM) or PCM, indicates that there’s a very specific voltage problem within the 5-volt reference circuit, which can indicate...Chevy 2009 Cobolt. My fault code is p0641. along with a reduced power indication from odometer led display. Really confused on this one. in looking up the sensors attached to this 5v reference to ecm, it covers a wide range of sensors. I am beginning to think on thre line of MAP sensor due to the fault reoccures at speeds of …28 Jul 2016 ... [FONT="]"P0641 is a 5 volt reference circuit 1 code. ... I can tell you from personal experience a P0641 is a nightmare. That 5v reference ...Doing a repair or project?? Want to be part of a Friend's Edition Episode? Interested Subscribers should contact Rob at [email protected] Absolutely NO-E...Code P0641 stands for Sensor Reference Voltage 'A' Circuit Open. In the event of a sensor reference “A” malfunction, a trouble code will be stored and a service engine soon lamp may be illuminated. PCM supplies a reference voltage to many of the onboard sensors. Typically, this reference signal is 5-Volts. The sensors then verify this ...P0641 yukon gmc 2008 code reduced power silverado cut stored mode chevrolet escalade cadillac tahoe sparkys answers shaft drive front Impala chevy ghost machineP0641 gmc yukon code 2008 reduced power answers stored mode sparkys Gm 4.8l / 5.3l / 6.0l v8 engine sensor locations – troublecodes.netP0641 code duramax throttle lb7 chevy gmc diesel ...How to fix engine power reduced, code P0641 2006 Impala LS 3.5L V6. chevy impala. car trouble ...more.31 Aug 2019 ... codes. ScannerDanner Tools: https ... (Chevy Tahoe) P0641 Shorted 5V Reference 1 Circuit Quick Tips ... Ford Explorer Setting Multiple Output ...When I find a stored P0641 code, it means that the powertrain control module (PCM) has detected an open circuit for a particular sensor; designated in this case as "A". When diagnosing an OBD-II code, the term open could be substituted for absent.Jul 17, 2022 · The cost to diagnose the P0641 2015 Chevrolet Silverado 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. 5 Jul 2022 ... How to fix engine power reduced, code P0641 2006 Impala LS 3.5L V6. chevy impala. car trouble.P0441 is one of the more common OBD II codes that can occur in the Chevy Silverado . It is frequently caused by a loose or bad gas cap, cracked or disconnected EVAP system hoses, vacuum leaks, or a bad purge valve. Always start by taking a look at the gas cap. P0441 is related to the evaporative emissions control system (EVAP) and …Jan 2, 2014 · DTC P0641 5-Volt Reference 1 Circuit. Conditions for Running the DTC. • DTCs P0601, P0602, P0604, P0606, P1621, and P2610 are not set. • The ignition is in unlock, accessory, run, or crank mode. • The ignition voltage is greater than 5.2 volts. • DTC P0641 runs continuously when the above conditions are met. My son's 2009 chevy silverado with a 6.0 liter engine died and has the following trouble codes: P0121, P0230, P025A, P0449, P0452, P0521, P0641, & P069E … read more Expert6 Jul 2023 ... this is Chevrolet Tahoe 2009 with 5.3L engine comes to the workshop with a problem of engine power reduce. I scanned the vehicle got P0641 ...Sep 18, 2023 · DTC P0641 stands for “Sensor Reference Voltage “A” Circuit/Open.”. It’s triggered when the PCM detects voltage that doesn’t match manufacturer specifications on the 5-volt reference circuit. Code P0641 is typically caused by malfunctioning sensors, wiring issues, and PCM problems. DTC P0641 5-Volt Reference 1 Circuit. Conditions for Running the DTC. • DTCs P0601, P0602, P0604, P0606, P1621, and P2610 are not set. • The ignition is in unlock, accessory, run, or crank mode. • The ignition voltage is greater than 5.2 volts. • DTC P0641 runs continuously when the above conditions are met.I got this off a silverado forum: [FONT="]"P0641 is a 5 volt reference circuit 1 code. [/FONT] I can tell you from personal experience a P0641 is a nightmare. That 5v reference circuit runs about 12 different sensors. Most of the cases I have work on have turned out to be chafed wires near the ECM.The PCM monitors the voltage on the 5-volt reference circuit. If the PCM detects that the voltage is out of tolerance, DTC P0641 sets. The engine is running. - The PCM detects a voltage out of tolerance condition on the 5-volt reference circuit. - The above condition is present for longer than 2 seconds.Aug 15, 2017 · P0641, P0651, and P0697. These DTCs set when the ECM detects a voltage out of tolerance condition on the 5-volt reference 1, 2 or 3 bus for more than 3 seconds. P0642, P0652, and P0698. These DTCs set when the ECM detects a low voltage condition on the 5-volt reference 1, 2, or 3 bus for more than 3 seconds. P0643, P0653, and P0699. P0641 signifies an open circuit in sensor reference voltage A. Voltage fluctuations indicate sensor malfunctions. PCM supplies 5-Volt reference to sensors. …About Press Copyright Contact us Creators Advertise Developers Terms Privacy Policy & Safety How YouTube works Test new features NFL Sunday Ticket Press Copyright ...DTCs P0641, P0651, P0697, and P06A3 are Type A DTCs. Diagnostic Aids. P0641. The 5V reference 1 circuit provides 5 V circuits to the following sensors: Air conditioning (A/C) refrigerant pressure sensor. Exhaust and intake camshaft position sensors. Fuel tank pressure sensor. Multifunction intake air sensor. P0651.When the PCM detects an open circuit in the ‘A’ reference voltage circuit, it stores the P0641 code and may trigger the check engine light on your Chevy Suburban. Keep in mind that the P0641 code is a generic trouble code, which means it applies to all model years of the Chevy Suburban built after for the 1996 model year and up.Chevy Mechanic: Greg. Richard Probable Causes for this code P0641. A/C Refrigerant Pressure (ACP) Sensor. Camshaft Position (CMP) Exhaust Sensor. Camshaft Position (CMP) Intake Sensor. Engine Control Module (ECM)Fuel Pressure Sensor. Fuel Pump Control Module (FPCM) Fuel Tank Pressure (FTP) Sensor. Intake Manifold …
9 posts · Joined 2015. #1 · Feb 2, 2016. Anyone ever experience an intermittent ABS, Service ESC, Service Traction Control lights coming on all at once? I have a 2008 Chevy Malibu 2LT with 3.6L V6, and recently I have had these lights come on. So I took the car to the dealer and had the Body Control Module recall completed and …. Little anitas locations
The currently selected ODB-ii codes is for the Acura makes. 2. Look up the other OBD II Trouble Codes, please use the search box. Enter the 5 character trouble codes in the search box and submit the search. 3. Don’t assume a particular OBD-II code means the same for other auto manufacturers as there are many makes specific codes in use. 4.2009 Suburban LT 4x4 5.3 Flex fuel engine. I swapped the ECM a few months ago due to a Po641 code and the truck not coming out of a limp-home mode. ... Chevrolet Corvette: code p2101 and p0641 on 2007 corvette. code p2101 and p0641 on 2007 corvette Car drives normal during normal driving, it only happens when I get on it ...This code means that the car’s computer detected trouble with the EVAP system vent valve’s function. This vent valve is also known as the purge valve. The computer is responsible for monitoring and controlling the purge valve. If the P0446 DTC sets, it could indicate that there’s an electrical failure in the circuit or a mechanical ...2010 Chevy Cobalt code P0641 Yahoo Answers. Read full answer. Sep 23, 2014 • 2010 Chevrolet Cobalt. 0 helpful. 1 answer. Chevy cobalt 2010 scan code po641 reduce ...How to fix engine power reduced, code P0641 2006 Impala LS 3.5L V6. chevy impala. car troubleMy son's 2009 chevy silverado with a 6.0 liter engine died and has the following trouble codes: P0121, P0230, P025A, P0449, P0452, P0521, P0641, & P069E … read more ExpertDoing a repair or project?? Want to be part of a Friend's Edition Episode? Interested Subscribers should contact Rob at [email protected] Absolutely NO-E... Summary. The P0651 code stands for “Sensor Reference Voltage “B” Circuit/Open.”. It’s triggered when the powertrain control module (PCM) detects issues with the 5-volt reference signal. Blown fuses or fusible links are possible causes for the code. Rough running and misfires are two symptoms to keep an eye out for. If you’re in the market for a new or used Chevrolet vehicle, it’s important to find a reputable dealership near you. With so many options available, it can be overwhelming to choos...Expert 224 Answers. Posted on Oct 09, 2014. Possible causes. - Faulty Engine Control Module (ECM) - ECM harness is open or shorted. - ECM circuit poor electrical connection. - Shorted sensor on 5 volt circuit.What is P0641 code and How to fix it. Thnx. 0 votes. 4.8k views. asked Oct 16, 2018 by Jess. 2007 Chevrolet Uplander - engine code came up while I'm driving and it says on my dashboard , reduce engine power.I checked it on my portable OBD code tester and says P0641. Any knowledge of this code and inexpensive way to fix.To diagnose the P0641 GMC code, it typically requires 1.0 hour of labor. The specific diagnosis time and labor rates at auto repair shops can differ based on factors such as the location, make and model of the vehicle, and even the engine type. It is common for most auto repair shops to charge between $75 and $150 per hour.Codes P0532, P0522, P0452, P0335, P0106, P0101, P0651, P0336, P2135 and P0068, P0107, P0315 or P0641 may also be set. P0641 is a 5 volt reference circuit 1 code. The 5-volt reference 1 bus provides 5 volts to the following sensors: The manifold absolute pressure (MAP) sensor. The fuel tank pressure (FTP) sensor.Step 3: Inspect sensors and wiring harness. Inspect all the sensors associated with the P0641 code, making sure to check for any visible damage, corrosion, or loose connections. Additionally, examine the wiring harness and connectors for signs of wear or disconnections, as these could also contribute to the problem..