The engine control module ECMalso commonly referred to as the engine control unit ECU or powertrain control module PCMis one of the most important components found on virtually all modern vehicles. The ECM takes the information from the engine's various sensors and uses that information to calculate and tune engine spark and fuel for maximum power and efficiency.
The ECM plays a crucial role in newer vehicles, where many of the essential functions of the car are controlled by the ECM. When the ECM has any issues, it can cause all sorts of problems with the vehicle, and in some cases even render it undrivable.
A bad or failing ECM may produce any of the following 5 symptoms to alert the driver of a potential problem. The Check Engine Light usually illuminates when the computer detects a problem with any of its sensors or circuits. There are cases, however, where the ECM illuminates a Check Engine Light mistakenly, or when there is no issue present. Have a mechanic scan the computer for trouble codes to diagnose whether the issue is with the ECM, or elsewhere on the vehicle. Erratic engine behavior may also indicate a bad or failing ECM.
A faulty computer may cause the vehicle to intermittently stall or misfire. The symptoms might come and go and not appear to have any sort of pattern to their frequency or severity. Engine performance issues are another symptom of a possible problem with the ECM. If the ECM has any issues, it may throw off the timing and fuel settings of the engine, which can negatively affect performance. A faulty ECM may cause the vehicle to experience a reduction in fuel efficiency, power, acceleration.
If the ECM fails completely, it will leave the vehicle without engine management control, and will not start or run as a result. The engine may still crank, but it will not be able to start without the vital inputs from the computer.
Car-starting problems are not exclusively caused by the ECM, so it's best to get a complete diagnosis by a professional technician to accurately determine the cause. Bad fuel economy may occur from a failing ECM. A faulty ECM disallows your engine from knowing how much fuel to burn in the combustion process.
Typically, the vehicle consumes more fuel than it should in this situation. The ECM plays a vital role in engine performance.
Any issues with it can cause major problems with the overall functionality of the car. As the computer systems found on modern vehicles are quite sophisticated and complicated, they can also be difficult to diagnose.
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Related Articles. Related Questions. Engine making weird noises and revving With these combination of symptoms, it sounds like your car has a drive belt problem.Discussion in ' Trucks [ Eighteen Wheelers ] ' started by joecitizenDec 8, Log in or Sign up.
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Apr 23, Rookie Here We had a truck shut down in Grantsville, MD. Next morning he worked on it till afternoon, came back to and told me its ready. We had a corroded power line to ECM he replaced it with a new fuses and patch of wire, a partial not the whole line.
Driver went in pick up the truck it was running fine, after he was hooked to the trailer, truck stalled again, they took him back in the shop and came back telling me that ECM is blown because of corroded wire. Is it that they must have done something stupid while putting that patch of wire that blew ECM. When I talked to the freightliner where he bought ECM from, they gave me core value.
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There is no charge for this service, but standard message and data rates may apply. I had the same problem I wound up running a new power wire from fuse box to ecm and the problem went away.
It was a 3 dollar fix that had cost over This worked for me but as you know this might not work for you. But I would at least try a new power source from fuse box to brain box it dang sure can't hurt!! Kw Owners Club Thanks this. Usually when the ECM shuts down because it lost battery power it will log a code.
It helps to further diagnose power problems. Most ECMs have more than one power wire. You may just have to run the engine and then grab and start shaking the wire harnesses to the ECM to see if you can induce the problem and find the problem area. I have seen new wires installed but they did not replace the actual terminal in the connector body and the terminal is completely worn out. I have also seen improper butt connections that failed right away. ECMs are pretty tough, I would replace one only as a last resort!
HeavydApr 23, You should find a fuse in the battery box for this power source. If you lose power at both these pins at the same time the ECM will never show a fault code. You also have two seperate ground wires on pins 65 and Again this wire usually leaves the battery box as a single wire splitting into two at the ECM.
I'd say the problem is on one of the wires leaving the battery box and before it splits into the seperate pin locations. HaneyApr 23, I had the same issue this winter on my '98 WS My driver called and said that the truck shut down.Mirandajo81 New Member. Wolf0r Top Member. USA Posts. Cal Mc Advanced Member.
Symptoms of a Bad or Failing Engine Control Module (ECM)
Any suggestions would be greatly appreciated. I wouldn't be asking but I am having one being sent to me at this time. If so, the speedometer is the main driver for the rest of the guages. We have had numerous problems with this master guage. Out of our 6 visions we have changed three of the speedometers. It's probably just an error. There is a procedure where you scroll to LIN Data on the gauge. If for example the gauge looks for a trans temp sender or air brakes, and your bus doesn't have these.
You scroll down and delete the inactive ones. Since it all runs together it was shutting it down like a domino affect. Thanks for all the help! I had already replaced it 2 years ago for the same crap. I'm ready to sell this POS to the farmers for hauling melons.
It's got the C7 anyway so it wouldn't be missed much. No wonder people get angry. I feel bad now asking the OP if he had a service manual. Sorry Dude. GPS was feeding it 12v. School Bus Fleet Magazine Forums. Mirandajo81 New Member 3 Posts. Do you have a service manual? Cal Mc Advanced Member Posts.
I think this has the same dash as our 07 Vision. We finally found it I got an 05 Vision that the multiplex drains the battery, won't go to sleep. Page of the 05 Vision manual. Dingleballs at the school corp hooked their GPS and 2 way radio to the ign side of the multiplex power.
CAT C7 Specs and Engine History
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Ford 1. Warranty see all Warranty. No Warranty Unspecified Length Lifetime The ECM provides split-second monitoring and data output for vehicle safety and functionality. It ensures that your CAT truck or equipment is operating at its most optimal performance. The ECM monitors several components such as a vast network of sensors and your emission control system. Caterpillar ECM modules come in a variety of shapes and sizes.
Most applications are commonly referenced by the pin configuration for the connectors. Identifying the number of pins can help determine which application you have and can sometimes even determine the engine type and size. The most common pin configurations are pin, pin, and pin applications.
Your Caterpillar ECM will always be located on the cool side of the engine. This makes a lot of sense considering the large amount of heat your engine produces. Engine temperatures can get upwards of degrees Fahrenheit. The control module is typically bolted to the side of the engine block using 4 mounting points.
The Caterpillar ECM will also typically have 2 main engine harnesses running to the connectors. We recommend a certified technician assist with any removal or installation of your Caterpillar ECM. Programming a Caterpillar ECM requires some very expensive programming and calibrating software. Caterpillar software includes diagnostic capabilities and an extensive library of calibration files and parameters for each specific engine. These control modules are very complex and even though they might look the same, each module carries a unique set of features and settings.
Think of your Caterpillar ECM as a circuit board strapped to a scorching hot engine exposed to dirt, grease, oil, water, and heavy vibrations. These are the exact opposite conditions that these modules should be in for long-term optimal performance. No injector pulse and lost data activity are common symptoms of a faulty ECM. These faults are usually triggered due to component failure.
Defective sensors and even a bad battery could cause electrical elements to overcompensate for the lack of power, thus creating inconsistent voltage spikes to your ECM. Still not sure if your Caterpillar ECM is bad?At the turn of the century there was a lot of buzz around a new diesel engine being produced at Caterpillar, one that could meet the growing emissions requirements enacted by the EPA.
The engine was produced from to and was installed primarily in over the road medium duty class 8 trucks. All of the big players in the trucking industry hopped on board hoping the CAT C7 was going to live up to the hype.
The technical classification of a medium duty tuck is a single drive axel with a gross vehicle weight of 18, lbs. The Caterpillar C7 was designed mostly out of necessity vs. Caterpillar, needed to produce a new engine that was going to meet or exceed the Tier Ratings enacted by the EPA in to curb diesel engine emissions.
The stricter Tier 4 emissions requirements went into effect January 1, The Caterpillar C7 was released inonly months ahead of the Tier 4 ratings change, and replaced the popular model. Older CAT engines like the or were essentially grandfathered into the older tier rating requirements and did not need to be upgraded.
The engine configuration was the same as the but the fuel system changed using a new engineered style known as the HEUI injector. The HEUI injector allows for multiple injections at different metered rates. Using a staged fuel distribution ratio helps improve engine combustion which ultimately reduces emissions ouput.
The electronic configuration was also more robust to offer better fuel management and electronic sensors into the engine. The ECM is the same hardware as previous electronic engine generations just upgraded to handle more systems. Using an advanced pin connection the amount of information the computer was able to process was astronomical. The cylinder heads are slightly different in the common rail design, still 3 valves per cylinder but there is no oil rail cast in the CAT C7 cylinder head.
The front gear train is mostly the same except for the gears which have fewer teeth and a more robust design. When examining the crankshaft and rods the common differences between the CAT and the CAT C7 include smaller crankshaft counterweights to include the lighter weight piston design. The connecting rods and crankshaft share the same journal sizes but are slight different in terms of cast size and shape.
There are also various sizes and configuration of the connecting rods depending on the piston used in the engine. Horsepower is the determining factor when choosing the piston configuration in the CAT C7. The two options include a taller aluminum piston with a 1. With the upgraded ECM the technology allows for a more precise control over the combustion cycle by monitoring the incoming air and fuel as well as the exhaust after treatment.
The more midsized hp models used only a single turbo while the larger horsepower models used dual turbochargers working in conjunction for optimal airflow.
Within the design of the C7, the turbos use variable geometry valve actuation controlled by the ECM to adjust the perfect amount of airflow into the combustion chamber.
This variable valve actuation also allows for the CAT C7 to offer an integral jake brake on two of the heavy duty diesel horsepower models. The fuel delivery system on the CAT C7 is hydraulic electronically controlled unit injectors for the mid horsepower models and mechanically actuated and electronically controlled on the higher horsepower models. Both systems are metered and timed to inject multiple bursts of fuel to create a more efficient combustion cycle.
intermittent power lost to ecm
The after-treatment technology reduces NOx particulate matter in the muffler via a spray of an oxidation catalyst agent. The after-treatment function is fairly straightforward and requires no additional cleaning or maintenance. With diesel engine technology there are two rating systems to determine the average life expectancy of the engine: B10 and B This means half of the CAT C7 engines had a major engine failure atmiles and needed an overhaul. Failures or parts replacement without removing the cylinder heads or dropping the oil pan are not counted in the B10 and B50 engine life statistics.
For example the B50 rating for the popular Cummins 5. However, a Detroit Diesel 60 Series can easily go 1, miles before overhaul. The technology was really the first generation emissions technology for heavy duty diesel engines. Drivers reported low power and low fuel economy. The cooling fan does not kick in until degrees Fahrenheit while many drivers reported overheating at degrees Fahrenheit.
The engines run hotter to burn off more diesel particulate matter. Drivers are instructed to downshift to rpm when going up an incline to avoid overheating.I have had much problems with the engine C -7 Acert. Especially in the injectors and diesel pump. I 'm seeing it is a very common problem. It is aand has an exhaust after-treatment. It shut off on me. I was certain that a fleet owned truck with low miles was in solid condition, but next time I buy CAT, I will check all the past records available with a CAT dealer.
Problems the truck has, first two diesel mechanics misdiagnosed it many times, the CAT dealer found the issue. This gummed up the DPF, which was baked a month ago, but soon became caked again.
Injectors had been replaced earlier, from leaking. I see there are common problems with the C7.
How Does a Caterpillar ECM Work?
It seems to be an engine that needs a lot of attention, and is quite costly as a result. I have other engines, in other vehicles, and never, in 20 years, have I ever had such a catastrophic level of expense for an engine, on such a relatively isolated component.
It makes no sense at all. Why isn't Caterpillar responsible for a recall on the engines? From what I gather, they are complete junk. Thank you so much for truly a veritable knowldege. It really worked for me.
The key idea behind it is pretty amazing and glad to know about it. Thanks for giving this information this really useful to me C7.
The idea pretty amazing thanks once again. Skip to Main Content. Expand search. Search Search. View This Post. August 10, at AM.