A car that shuts down after a 1 second warning, to me, is extremely dangerous especially when driving in the fast lane on a motorway and it beggars belief that a big company like Citroen do not put a failsafe in place? ECU acting up do you think? Thank you for your help . What up people. I have a 2009 Saturn Vue with 132,000. Hi Sean… I’ve been looking around the internet and came across the fuel pressure specs. Check engine light was on and reading fault codes in regards to the transmission. Then you will have a malfunctioning ECU. Smart Car MPG – What Kind of Gas Mileage Can You Expect? The ECU regulates virtually every important system and function in your vehicle. Strong compensation one way or the other could mean a vacuum leak, clogged or leaky injector, etc. This will require you to get the ECU repaired or possibly even replaced. The fact that your short term fuel trims are around 0 at idle is a good sign. With a fuse puller or tweezers, pull the fuse locate… If the voltage is 6 or less, then this is likely causing your ECU problems. Changed plugs and injectors and ran okay for a couple weeks then PO172 code comes up. There is wiring that runs into the harness of the ECU where you can check the voltage amount. These upgrades were 28psi to open and was a 4 hole injector. It’s unlikely they bypassed the main fuse (probably the “surge protector” you’re thinking of). My LT fuel trims are pegged at 25% and the short terms are hovering around 0 at idle. We had it checked and now we are getting a code related to voltage and the ecm. Gauges and warning lights keep coming on. Do you still have a set of factory injectors? Related: How to Clean Corroded Battery Terminals. Most thermostats are mechanical devices, not really sensors. The ECU fuse should be clearly marked on the outside of the fuse box cover or in the owner's manual. Thanks. Just waiting in the injectors to come in. Dodge dealer tells me van needs a new transmission. If an overheating issue is left unchecked, it can cause a more serious problem such as blown head gaskets (assuming that’s not the root cause). Check all fuses to make sure none are blown. My car a missing problem which is unstable slow speed . Variety of problems, seemingly all random. It then would not start. It wouldn’t take you long to realize the ECU was responsible. What do you think? Took it to another mechanic who looked at it and told me he has no idea what’s wrong with it but doesn’t think its the ECM. Hey Sean, just an update… found remanufactured injectors and ECU at an affordable price. Since the misfire keeps returning I am wondering if the issue lies elsewhere, such as a bad ground or ignition coil. I would try them to see if it fixes the problem. To rule out air and fuel, check fuel trims to make sure it isn’t running too rich or lean, as this could also cause a misfire. However, I think it is more likely that there is a parasitic drain. The car will only run for 8-10 seconds at a time. my truck then cut off as i pulled over.i thought i had a blow out but my tires was good..when i tried to start it it would not start. Totally body is shivering while my car showing missing . I found this “4.8L, 5.3L, 6.0L or 8.1L your fuel pressure should be 55 – 62 psi with the key on – engine off”. If one rail is bad or leaking, I would expect a higher ST fuel trim on that bank. My 2015 Nissan Altima was having issues. Make sure any new starter that you purchase has the right sensors which can communicate with the ECU properly. Is a new part defective, incompatible, or hooked up wrong? Started the car & kept saying engine too hot, the engine was cold had plenty of water in it. In some cases, an electrical issue could cause several systems to fail due to incorrect voltage, too much resistance, etc. There is also staring trouble like engine is not stable while i jumb small humbs and gutters . It is also often referred to as the PCM (powertrain control module) or ECM (engine control module). Had the van towed. The starter was fine with no problems when I dropped my van off to them. Here’s what I have done within 8 months ago… I was told that the fuel pressure for the T model Avalanche is to be 55psi or higher. Then hours or days later I’ll start it up and have it only at 600 RPMs again and wanting to stall when I put it into geae. I would get a second opinion on that diagnosis. I am on the correct pins and following the instructions to the “t”. Nothing would work not even the locks on the doors. I found a good source for your car that may help: https://www.club3g.com/threads/how-to-testing-iac-idle-air-control.140906/, Hi I was driving my when the temperature idle went to the limit & the warning was engine too hot. Read also: Car Immobilizer: Basic Function and Bad Symptoms. My battery keeps on draining. You may see an issue with an O2 sensor or catalytic converter. Hi everybody. Changing each sensor isn’t going to help in this situation, since the problem is with the wiring somewhere. My other question is could they have bypassed the surge protector on the ECU when they replaced the starter thus causing the ECU failure? Check to make sure your multimeter is set correctly. They then call me and tell me that my starter was now making a loud noise so that would need to be replaced as well. The engine and drivetrain are the most dependent on the ECU. That was 6 months ago, today while getting my car washed the warning come on same reason as before so I changed the sensor again. Honda vs Toyota: Which Brand is More Reliable? I pulled over and turned off the van. If you were to ever have a bad ECU, then many noticeable symptoms would present themselves. I had it towed, and looked at and the mechanic said there are 14 codes in the ECM alone which suggests communication issues. If you hooked up the jumper cables backwards it could be any number of things. Affiliate Disclosure:  We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites. High fuel consumption and black smoke could be an indicator that the car is running rich. I am skeptical of changing injectors like that without retuning… that may be your issue. I recently bought a 00 civic with a B20 swap. This site uses cookies to offer you a better browsing experience, by continuing to browse you agree to the use of cookies - find out more/change settings, Mon-Fri 9:00am-10:00pmInternational dial +44 1773 535638. You won’t be able to even start your vehicle and get the engine running. lights, applications, sensors…? If you still have your original fuel pump, you could try switching back and checking the pressure to see if it’s similar. I have intermittent issues with low idle RPMs and stalling while idling and while driving. Scan for codes, they may give you a clue what the problem is. The Service Stabilitrak code recently started going off, then the brake code and the ABS code, then all of a sudden that little car with the wrench inside came on and the car drove in safe mode. Providing your year/make/model and a description of the symptoms would help narrow down the cause tremendously. a subaru specialist diagnosed a bad ecu and changed it. I have a tech 2 scanner I’m using. Which new part is causing the issue? And…cooling fans run at high speed from startup to 15 minutes after shut down even with cold engine and A/C off. You can try googling something like “08 outback H6 cylinder 1 and 6 misfire”. Look up your owner’s manual (or a forum) for the proper procedure for checking codes on your vehicle. That’s very strange. Are the fuel trims off only on cylinder #3? I am totally at a loss… please help, thanks. We ran codes and changed all the sensors that were identified. Is that normal? Once open, this brings cool water (or coolant) from the radiator into the engine and allows the hot coolant to move to the radiator, where it is cooled before reentering the engine block. It sounds like you have your bases covered with the simple tests; you certainly covered all my initial suggestions. Maybe this is the problem??? I bought the Tech 2 used so I hope it isn’t that. Then it would malfunction and cause further problems in your vehicle. You were right in steering away from the ECU. When the ECU has any issues, it can cause all sorts of problems with the vehicle, and in some cases even render it undriveable. I have 3 different IACs that I’ve cleaned and switched in with no change. If this sensor were to go bad, then the ECU would not receive the correct amount of voltage. 14 months ago I was getting a check engine light and found the error code p0306, cylinder 6 misfire. Though the power did get better it’s still has a hard time getting out of it’s own way. from what you’ve listed here I’m guessing that the voltage is too much or too little and shorting out the ecu. after changing the spark plugs and ignition coil packs I was still getting the failure. To access the ECU fuse, simply pop the hood of your vehicle and open the fuse box. Then I changed some fuel lines, fuel filter and the injectors. 4. Do note that fuses probably won’t protect the ECU if there is a bad connection on the ECU’s circuit board that is causing some short or open circuit. Most places will do this for free. Well, I agreed to have them test it further because these codes only go off intermittantly then stop for a couple days, then start going off again. This leads me to believe there is a fueling issue where the engine is not getting enough fuel under load. Didn’t check the other cat though. If the seals become too worn, it will be easier for moisture to pass through them and enter the ECU. If you attempt to jump start your vehicle with the cables attached incorrectly, then it could short out your ECU by causing it to spike too quickly. Put Too Much Oil in Your Car? Think of it as the vehicle’s brain. The thing is I took it to mercedes repair shop they opened the ECM and said they found corrosion in it and that it’s hard to define the actual reason for the failure. Today it was idling for 15 minutes just fine, drove 15 minutes no problem, drove back 15 minutes, idled 15 minutes again, then finally it was stalling non stop. The codes I get are P0170, P0174 and a p0300.