Error codes P0171 and P0374
I used the OBD II / EOBD CODE READER and found the following code (4 error codes)
P0171 System too lean Bank 1,
P0374 Timing Reference Hig n Resolution Signal A No Pulses,
P0171 System too lean Bank 1,
P0374 Timing Reference Hig n Resolution Signal A No Pulses,
The same code reader gave me RPM(rpm): 705.50 while the engine was running but the gear was in Parked position.
I don’t feel anything while driving the 2006 Ford Five hundred SEL (I don’t have much knowledge about vehicles), It accelerates well and goes easily to 40miles per hour when given the acceleration (I have not tried beyon
Experienced mechanics share their insights in answering this question :
Hello. These issues can be caused by a few things. From the codes it sounds like there may be an issue with the fuel system. It may also be an issue with the air intake system allowing too much air into the engine. The main code here is the lean code meaning too much air or too little fuel. I usually start by checking the fuel trim reading are in the computer to see what is going on. This would tell me if I am looking at a fuel system problem or possibly a sensor that is reading wrong. If these codes are present, the computer can also put the vehicle into limp mode which would explain why it is shifting like this. If you want to have these engine codes scoped, consider YourMechanic, as a certified technician can come to you to diagnose the Check Engine Light and pinpoint the underlying repairs that are needed.
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Too much fuel and/or too little air results in the engine running rich setting a P0172 trouble code, while too little fuel and/or too much air results in the engine running lean resulting in a check engine light for the Ford P0171 code.
A Code P0171 or system too lean bank 1 means either too much oxygen or too little fuel in the exhaust. This is a `lean` condition or a `low fuel trim` code. The P0171 OBD-II code indicates that the fuel system on the first bank of the engine is weak or that a vacuum leak exists near this side of the engine.
What Does P0171 and P0174 Mean? DTCs P0171 and P0174 are generic codes that set when the feedback on the engine`s air/fuel mixture becomes too lean for the Engine Control Module (ECM) to correct within its normal operating range. A lean mixture is a mixture that has too much air or not enough fuel.
A Ford P0171 is a LEAN code for cylinder bank 1, and P0174 is a LEAN code for cylinder bank 2. These codes commonly occur on many Ford vehicles, and are set when the powertrain control module (PCM) sees the air/fuel mixture is running too lean (too much air, not enough fuel).
What are the symptoms for a P0171 code? Generally, a lean code will cause the engine to run poorly, which the driver will notice as a high idle, a misfire, a lack of power, or even engine stalling, and this may happen before the check engine light has turned on.
You probably know that the answer the questions is — no! A P0171 or P0174 lean code with an O2 sensor reading lean all the time mean — well, several things. The real problem may not be a bad O2 sensor, but possibly be an engine vacuum leak, low fuel pressure or dirty fuel injectors that are causing the engine run lean.
How Serious Is Code P0171? While it is common for a driver to only experience minor driveability problems when the P0171 trouble code is present, driving with this code can overheat the engine and cause internal engine damage.
The P0171 code, and its related codes, can certainly range in seriousness. The code by itself doesn`t present any immediate dangers, but you should get it checked out immediately by a qualified technician. If the code exists for a longer period in the PCM it may cause further damage that is costlier to repair.
If you have codes stored in the engine computer for lean bank 1 and 2 is caused by the entire engine is running lean. This is caused by not enough fuel getting into the engine or too much unmetered air getting into the engine and the computer cannot compensate anymore to run it normal.
No, either an air leak,low fuel pressure or a dirty fuel injectors can cause it. In my car it was caused by a bad fuel pressure regulator,I also got a P0174 which was for the right hand engine bank..
The most common fault codes associated with a clogged fuel injector are P0171 and P0174, which indicates the engine controller is seeing a lean condition.
When the ECM/PCM is having to add too much fuel based on input from the O2 sensor, the fault code P0171 will be sent to the ECM, which will trigger the check engine light to illuminate. This code could either mean that the oxygen sensor is detecting too much oxygen or too little fuel in the mixture.
Relevant Questions and Answers :
the most relevant questions and answers related to your specific issue
Error codes P0171 and P0374
ANSWER : Hello. These issues can be caused by a few things. From the codes it sounds like there may be an issue with the fuel system. It may also be an issue with the air intake system allowing too much air into the engine. The main code here is the lean code meaning too much air or too little fuel. I usually start by checking the fuel trim reading are in the computer to see what is going on. This would tell me if I am looking at a fuel system problem or possibly a sensor that is reading wrong. If these codes are present, the computer can also put the vehicle into limp mode which would explain why it is shifting like this. If you want to have these engine codes scoped, consider YourMechanic, as a certified technician can come to you to diagnose the Check Engine Light and pinpoint the underlying repairs that are needed.
Error code P0171 and P0374
ANSWER : Hi and thanks for contacting YourMechanic. If the vehicle went into limp mode, then the computer is making this happen to prevent the engine from any damage. Check the camshaft sensor for proper timing to the camshaft. Look at the harness and make sure that it is plugged in and free from any moisture. Since the engine is running good, the crankshaft sensor is working correctly. Disconnect the camshaft sensor and drive the vehicle around to see if there is any change to the performance of the engine.
If there was no change, then the camshaft sensor needs replaced. If it did change then, you will need to check the timing of the engine with a timing light. When checking with a timing light, make sure that the timing flash is on the same point. If the timing is not at the same point, then the engine will need a timing chain and / or tensioner. If the timing is steady, then the camshaft sensor needs replaced. If you need further assistance troubleshooting your vehicle, then seek out a technician, such as one from YourMechanic, that can assist you with the engine codes coming up.
The TPS error code P0123 appears only when the AC is on
ANSWER : Hello. The low charge in the A/C system is going to cause the A/C compressor to work harder than it should. This will put a greater load on the engine and may cause your throttle position sensor to give a bad reading. Have a certified technician set the A/C system to the proper levels and see if the P0123 code continues. Having the throttle body cleaned may also help fix this problem. If you need help with this, a certified technician from YourMechanic can come to your car’s location to diagnose the code more thoroughly in order to have this corrected.
only had code P0171 then I went back and this time I also got a code P0068 throttle body along with the P0171
ANSWER : Hi there. Those codes may or may not be related. Proper diagnostic processes will determine the root cause of the failures. When the ECM detects a fault it stores codes. It does not know why or what caused the fault, only that the fault is present. You can always try to clean the parts you mentioned, but it would literally be a blind guess and most likely not a proper repair. I suggest having a qualified technician perform an inspection to avoid replacing unnecessary parts. Your Mechanic has several available technicians that can assist you with a check engine light inspection.
Check Engine Light is on – codes P0313, P0299, P0304
ANSWER : Hi there. Based on what you’ve described, this could be a combination of faults between 2 or more things; however, I don’t believe the coils and spark plugs are at fault. One of the codes is set during a low fuel misfire (lean condition), one is specifying a misfire on cylinder 4, and one is a turbo related code; all based on a generic code investigation.
The make and model of the vehicle helps, but is not necessary at the moment. When a low fuel pressure misfire is set, there is a lean condition that has been detected by the sensors and one of the codes is telling us in which cylinder this is occurring. A possibility is a restricted fuel injector, loose injector harness, poor pin fit in the wire harness, and an air leak near that cylinder’s port in the intake manifold.
I’m leaning more towards a leak or crack somewhere creating an air leak since we also have a turbo related code stored and an intermittent rough start when cold. I strongly suggest having a qualified technician perform an inspection to determine the root cause. YourMechanic has several available technicians that can assist you with a Check Engine Light inspection and determine exactly what is giving rise to codes P0313, P0299, and P0304.
Camshaft position sensor error code P0343
ANSWER : Hello. The P0343 code indicates there is no signal from the passenger side cam position sensor (Bank 1 actually). Given you have changed the sensor, this would suggest a wiring or connector issue. Your mileage would also make me anxious about timing chain guides, tensioner and timing chain – a chronic maintenance item on BMW V8s with this sort of mileage. While the timing chain service is a bit expensive, the alternative is even more so. I recommend having a certified technician from YourMechanic to thoroughly inspect the Check Engine Light and proceed with the appropriate repair.
I have a Code P0601 on the PCM. I replaced the PCM, and now I have a code P0118, code P0123, and code P0193.
ANSWER : Hi there, the short answer to your question is no . A PCM with a P0601 (which is a memory module error in the PCM) cannot reliably retrieve codes for the codes you list (P0118 – coolant temp sensor, P0123 – throttle position sensor, P0193 – fuel rail pressure sensor.
Most likely, the P0601 prevents the PCM from getting any codes from the engine sensors. The memory module error may cause in data corruption for collected sensor values, lose of data over multiple sampling periods, or failure of the data collection to work at all. Replacing the PCM was a necessary expense.
If you need assistance with the "new" codes, I would recommend having a Check Engine Light inspection completed by a mobile, professional mechanic, such as one from YourMechanic, to diagnose the new error codes and get an accurate assessment of the repairs needed.
It threw a code 21 , throttle position sensor bad code. i replaced it and the code went away but i still have no spark.
ANSWER : Hello and thank you for contacting YourMechanic. The problems that you are encountering with your vehicle, could be caused by the harness to the Throttle Position Sensor (TPS) or the computer itself.
Check the harness to the TPS for any debris or any corrosion. Hook up a paperclip to the harness and turn on the key. Use a multimeter and check for voltage at the pins of the harness. Make sure that the ground on the sensor is grounded and has no resistance. If you find that the harness is having too much resistance, then I recommend having the main engine harness replaced. If you have replaced the harness and still have the same problems, then the computer will need to be flashed or replaced.
I recommend having a professional, like one from YourMechanic, come to your home to diagnose your car’s no start condition before replacing any parts.
