The sensor is located in the control box of the gearbox; it registers the highest and the lowest gears of the range amplifier LR and HR. The position of the cylinder divider. The sensor is located in the control box of the gearbox; it registers the highest and the lowest gears of the divider LS and HS. The pneumatic pressure regulator is faulty or the sensor is faulty. The pneumatic components are not tight, the pneumatic pressure regulator is faulty, or the sensor is faulty.

A short in the sensor circuit to power or a sensor is faulty. A break in the sensor circuit wires or a sensor is faulty. Shorting wires in the sensor circuit. An open circuit in the sensor circuit or a pressure sensor is faulty. Faulty generator or external power supply to start the engine. Faulty generator. The frequency of rotation of the main shaft. The sensor is located in the control box of the gearbox.

The voltage drop in the sensor circuit or the sensor is faulty. A short circuit in the circuit of one of the valves S1 or S8 to the power supply. A short circuit in the S2 valve circuit is energized. A short to one of the S3 or S4 valves is connected to power. A short circuit in the circuit of one of the S5 or S7 valves to the power supply.

Solenoid valve of wide-pulse modulation PWM S The valve is located in the control box gearbox. Broken wire data channel, damaged or oxidized contacts in the connectors or faulty control unit. Partial damage to the data channel wires or oxidized contacts in the connectors.

The position of the cylinder 1 gear. The sensor is used to register the first, reverse gear and neutral position. Located in the control building. In order to avoid slippage in the clutch, it is necessary to choose the right gear to start moving. Do not press hard on the accelerator pedal.

MID 128 Fault Codes DTC

A short in the wiring between the control unit and the clutch cylinder. The solenoid valve of the internal position of the cylinder 1 includes the first transmission and the transition to the neutral position. The valve is located in the control gear case. The control unit is located in the control box of the gearbox.

The solenoid valve for the external position of the cylinder 1 reverse gear and transfer the neutral position. The solenoid valve of the internal position of the cylinder 2 includes the second gear and the neutral position. The solenoid valve of the external position of the cylinder 2 includes the third gear and the transition to the neutral position. Solenoid valve PTO number 1. Usually located behind the left front wheel in front of the battery box.

TMS data channel. Damage to the wires of the data channel or the oxidation of contacts in the connectors.FMI 1 — Data valid but below operational range. Fault code explanation:. Fuel pressure is too low. Fault indication:. Flash code. Electrical fault: 3. Conditions for fault code:.

mack fault code mid 128

The fuel pressure alarm depends on the engine revolution. Suitable action:. FMI 3 — Voltage above normal or shorted high. Possible reason:. FMI 5 — Current below normal or open circuit.

The voltage on pin B16 on the EMS2 is less than 0. FMI 7 — Mechanical system not responding properly. Fuel pressure depends on engine revolution speed. Fuel pressure is lower than the value specified in the engine protection parameter.

For parameters, see Administration page 7. Circuit description. The sensor is an active sensor, i. Pin 4 on the sen- sor is connected to battery negative via pin 18 on the EMS2. The output signal from the pressure sensor, pin 2 on the sensor to pin 16 on the EMS2, is a voltage signal that is proportional to the fuel pressure.By deercreekFebruary 9, in Engine and Transmission.

Decided to start a new thread on this as I really need some help. Have an 08 Mack granite gu that has been giving some grief. We have replaced the fuel filters about 3 times, blew out the accesible fuel lines countless times. It is an intermediate problem. The truck is currently at our local diesel truck mechanic, he is now thinking it might be electrical, I have had it down there like 3 times already, seems it always works good when he drives it.

Does anyone have any suggestions on what it might be? The easiest thing to check is the fuel pressure relief valve on the front of the head had one with the end broke out last week. Alsoif there is a Tee on top of the 7th injector this is a check valve that can go bad and air can be forced back into the fuel system.

Also check where the fuel supply pump bolts to the power steering pump and make sure it not dripping fuelor seeping from where they mate together. Check the plastic fuel lines and plastic fittings at the fuel tanks and make sure their not cracked. We have had a few filter stands go bad and start sucking air but in reality it probably the injector cups bad, the symtoms vary greatly when it comes to bad injector cups. Done 2 sets in the last 3 weeks and got another GU sitting in my bay to start on tommorrow.

There is a test we do to check for air in the return fuel. If there is alot of air bubbles then it's the cups. I would call a dealer and give him the VINmiles and engine hrs and see if its still under warranty. If still under warranty get the conical stainless cups and injectors installed If there not on backorder.

mack fault code mid 128

If not under warranty you can just replaced the copper cup that went bad to get by cheaply. Thanks alot for all the info. We ended up taking the truck to our local Mack Dealership. They finally got to it and called today. They said there was some oil in the engine harness and where the connector connects into the ecm? They were thinking that might be part of the problem. Have you heard of something like that? Replacing all that won't be cheap. They were going to do a test to check for air in the fuel lines and havent heard back from them yet.

I just can't quite see how it would be the ecm, would think it would cause more random issues. Okay, thanks for the helpfull info.

They also found some debris in the fuel lines and tank so we may have two things going on here. Thats good news on the ecm, hopefully a washing out will be good enough for it. Its sorta spendy. They are saying they first want to replace the harness and then see what the ecm does after replacing it.

So hopefully it will be all good. The truck was one that we rebuilt, it had layed over I think on the drivers side, so maybe that is part of the reason there was oil coming up that harness, beings the ecm is on the drivers side. You can post now and register later. If you have an account, sign in now to post with your account. Paste as plain text instead. Only 75 emoji are allowed. Display as a link instead. Clear editor.Decryption of codes of malfunctions DTC. The fan rotates at maximum speed, which causes high fuel consumption.

The unit detected excess pulses in the fan speed signal, the wiring is damaged or the insulation of the wires is bad, the sensor on the fan is faulty, the fan is faulty. High voltage or short circuit to high voltage circuit. The wire between the control unit from terminal EB31 and the K48 relay closes to a constant plus, the K48 relay is faulty.

Starting in cold weather is difficult. The code is only active if the ignition key is in the preheating position between the ignition on position and the start position. Low voltage or short circuit to a circuit with a lower voltage. The wire between the control unit from terminal EB31 and relay K48 closes to ground, the preheating relay K48 is faulty.

The air heater is constantly activated, as a result of overheating, the heating coil may be destroyed and parts of the spiral may get into the intake manifold and valve mechanism. Below current or open circuit. Open circuit, fuse for heating relay fuse blown, wire break between control unit and relay, relay power wire break. Heating does not turn on; starting in cold weather is difficult.

Abnormal refresh rate. If FMI 11 is present, the speed does not exceed rpm. Check integrity of data channel wiring.

mack fault code mid 128

The speed signal is transmitted via the SAE J data channel. If FMI 9 is present, the speed does not exceed rpm. The pedal position signal is not transmitted through the data channel SAE J, the sensor on the accelerator pedal is faulty, the data channel SAE J is faulty, the error is in the vehicle control unit. If FMI 9 is present, the unit enters idle mode. Check the integrity of the data channel, replace the accelerator pedal.When I got to my destination, one of the forum members helped me out to diagnose this code as a differential pressure fault for the EGR valve.

He said that sometimes a sensor line gets plugged with soot and causes the computer to "complain. And, then it "cleared" itself, as I was driving down the road.

MID128 Fault code – Volvo engine control units

For those of you who have a D16 engine, could you post a photo of the EGR valve? This will help me locate it on my engine and check out the possible plugged line. I know! A few days ago I posted the engine manuals for Volvo engines. D16 included. Mark put them up on the Guide.

May or may not be a help in understanding the systems. What I find with info like this is even if you can't fix a problem yourself at least you have some knowledge when taking it in for repair.

May keep you from getting fleeced. If that's right, I'd bet Jim should be looking at the exhaust gas pressure sensor. They have a habit of getting plugged with soot, and then becoming sluggish or ending up with readings that don't make sense. I know you guys have those fancy green engines, but on the ISX it's a second job to unscrew it and take a look.

And assuming the Volvo part isn't gold-plated, I'd replace it long before I started messing with the EGR system itself. We got back home, safely, today. The truck ran fine. On the way home, the truck threw the same code again and cleared itself in about an hour. At least it is being consistent.

Thanks to everyone for your thoughts. I received some good info and I am confident I can figure this out. I will post more info when I get to the bottom of this gremlin. I should have bought an older mechanical controlled HDT. BTW - I must have a guardian angel looking out after me. We were in the desert and the night temps were dropping down to 20 degrees.

One of our gold prospecting trips took us to a remote mountain area about 15 miles from camp. We drove a Yamaha Rhino up and down the hills. A couple of times when I pushed on the "go-pedal," The Rhino did not move and then lunched forward with an awful screech. Yesterday, as I was driving up the ramp of the toy hauler, to load up the Rhino, the engine rev'ed but theRhino did not go forward.

I had to roll the Rhino down the ramp, back it up and make a "high speed" approach to get up the ramp and then slam on the brakes dumb and scary once in the garage. I am guessing the clutch went out on it. I could have been in a world of hurt, if I lost the clutch in the mountains. The problem was the EGR pressure sensor. The dealer replaced both the sensor and the connector due to pin fretting.

The dealer installed Volvo's "updated" sensor. For those of you who want to fix this problem yourself, the sensor is located between the radiator and front of the engine, almost inaccessible.FMI 1 — Data valid but below operational range.

Fault code explanation:.

mack fault code mid 128

Oil pressure is too low. Fault indication:. CIU: Flash code. Flash code. Electrical fault: 3. Power is reduced due to error torque map if the engine protection parameter is activated. Conditions for fault code:. Oil pressure depends on the engine revolution. Oil pressure exceeds the set value of the engine protection parameter. Possible reason:. Suitable action:.

FMI 3 — Voltage above normal or shorted high. FMI 5 — Current below normal or open circuit. The voltage on pin B11 on the EMS2 is less than 0. A black. B black. Circuit description. The sensor which measures the oil pressure is an active sensor, i. The sensor, pin 4, is connected to battery negative via the engine control unit, connector A, pin Now that a standard had been set for both the physical connections and the software language, the manufacturers need a logical way to read and display this data.

Mack Truck Fault Codes - DTC Guides

This is where we first saw this new system. If you have ever used some diagnostic software or a generic code reader, these acronyms will look familiar.

Volvo Trucks - Volvo I-Shift. Now Standard.

Here is how they work. The MID tells which system it is coming from. There are hundreds of MIDs that are defined, but only a handful are commonly used. Here are the most common ones:. We have also compiled a list of all MIDs that are created. Please use the link at the top of this page to receive them. Parameters Identifiers, or PIDs, are numbers and names used to identify data being displayed. The entire PID list can be downloaded by filling out the form at the top of the page.

It is approximately 11 pages total. This code is set by the ECM detecting a variety of problems, such as too much voltage, not enough voltage, resistance is in correct, and so on.

So here is the list of possible FMI values:. Now that we understand that a MID is a component, such as an engine, it can be further broken down in to subsystems.

Each subsystem has its own set of SIDs. It is broken down by MID, which this list gives you:. It is approximately 40 pages total. You will never have both. While we do not have a list of these, it is important to know what they are. Before we can move much further, everyone needs to understand the relationship between J and J Basically, J worked great, but it was quickly becoming obsolete. This is because manufacturers started adding more sensors, needs to collect more data, and everything was getting more complex.

This is where we started seeing the 9-pin Duetch connector placed in trucks. One, PIDs go from 0 to SPNs go from 0 to over 50, Again, the SPN was needed because of the extra complexity of commercial trucks.

The other thing you would notice that both lists are almost identical from 0 to We have also compiled a list of all known SPNs, which is available by using the form at the top of this page. Almost all equipment manufacturers Also called OEMs take all of these acronyms we just discussed, and then translate them to an flash code. This is where a lot of customers run into problems. Lets use one of the code readers we sell as an example. The problem is that we do not know the true flash code that this ABS manufacturer uses.

At this point, the technician using the tool can attempt to find service manuals or use Internet searches to find repair and troubleshooting information. This is great, because now we actually find the repair information in a service manual or easily find the information online.

So there you have, a beginners guide to all those crazy acronyms that you see with commercial trucks and diesel diagnostic tools. We hope that this information gave you some insight into how these heavy duty scan tools work, and why you need to make sure you match up the correct tool with what you are trying to accomplish. Comments are always appreciated! Skip to main content.