Hello and welcome!

You have certainly thrown the parts cannon at your fault, but have you actually tested the wiring? The only reason I ask is that your initial code says voltage correlation, aka a possible short circuit could be your demon?

 

I have not tested the wiring as of yet as i have potentially ruled out the issue with a wire fault. but that is not to say that it could be the issue.

I am thinking that if it was a short circuit, i would see the code come back as soon as ignition was switched off and then back on again, but you will see from below that i can clear the code for a period of time and not have it come back, that is what is puzzling me.

My reasoning behind it, is if i clear the code i can run the car without any issues and no code appearing, if i start the vehicle within a 7 hour period from the code clear, the code doesn't show. but after 7 hours the code re-appears.

So basically this is what happens

6:30am start car and get code. Clear code
7:30am car parked up at work
12:30 start car during lunch break, No code present
16:00 leave work no code present
17:30 car parked up at house
19:00 pick up other half from her work, No code Present
19:30 Car parked up for evening.
06:30 start car and get code. rinse and repeat

i found this on the Honda Maris website. so i dont know why i can clear code but its only coming back after the car has sat for 7 hours or more, The evening\night temperatures have been between 10-15deg c.

It really has me baffled.

 

I have read on another forum that there could be a Honda service bulletin for codes P0181, but that was for a 2.2 idtec engine I think 🤔 and it was an Accord.

But essentially, it describes the same issues you're facing.

Fault codes P0181 and P2199

Hi guys. New to this forum, hoping someone might be able to help. I have a 2009 Honda Accord Mk8 2.2 i-Dtec manual. I recently had a DPF issue where the filter was clogged. I've had it cleaned and regenerated and that is all sorted now. However, a couple of days later I went to start the car in...

typeaccord.co.uk

 

I had seen that last night, but wasnt sure if it would be applicable, as you mentioned it is for an Accord. but it is possible that it could be related as i know that a few models share parts with each other.
Looking at the bulletin it did mention that thier is an Air temp Sensor in the MAP as well and the bulletin says to replace the MAP sensor, which contradicts Honda's diagnostics of replacing the MAF sensor. so have loaded up the parts cannon again and ordered a replacement as they are not that expensive, £20. which is much cheaper than going to Honda to get it checked, £20 would only cover the mechanic putting his cup of tea down, but not getting out his seat.

 

The P0181 is a circuit fault code. Saying it could be the fuel temp sensor or the wiring or the ECM. When modern cars are turned off, it doesn't mean they are completely off. Some do some tests to determine if the entire system is running right. Have heard of complaints where the car will make some noise in the middle of the night.

When the car is running, the conditions to determine whether the fuel temp sensor is reading correctly is not available. So, it doesn't do the tests. Later when the car is off, the ECM knows the ambient temp and the fuel temp sensor should be reading very similar. But, it doesn't so, it lights up the CEL. The ECM then determines the reading is wrong and puts up this code. It lets you know where to start looking for the trouble.

What does the Fuel Temp Sensor do? it allows the ECM to determine the state of the fuel and to know how much fuel to use to keep engine running at optimum efficiency. Old cars would just use as much fuel as it needed and polluted the air. There was no emissions system. Old cars ran much better without the DPF. But, we live in a world where emissions is a concern. And all these safe guards are in place to protect everyone's health.

Personally, I do not know enough about diesel engines to help. But, I know enough about DTCs to know what a circuit fault code is and what to look for. Search for Honda CRV P0181. Should come up with

"What is the code P0181 on a Honda CRV?
P0181 code is a fault code that deals with an issue with the Fuel Temperature Sensor 'A' Circuit Range/Performance."

Good luck.

 

@Colinn
There are a hundred one faults that can cause the PGM-FI error code, but my money is on a faulty Fuel pump relay.

I would suggest you swap-out the fuel pump relay for a new one they only cost around £16 pounds.

Please note I do not know the location of this relay on your CRV, but the screen shot below show the location on the old 2.2 iDTEC CRV which was located on the cabin fuse box.

But a simple telephone call to your local Honda dealer would confirm this or check in your owner’s manual.

 

HI Kev,

the model of CR-V that i have is the 2016 face lift version which has the 2 relays for the PGM-FI system. one relay in the engine bay and the other in the cabin fuse box.

I will have a look at getting a couple of replacement relays after i have swapped out the MAP sensor. As i wasn't aware of the MAP sensor and some people\websites get the terminology mixed and confuse the MAP sensor with the MAF sensor and vice-versa. I have now found that the car has both and they work in conjunction with each other, as i have already replaced the MAF sensor, i will go ahead and replace the MAP sensor also, then i will have peace of mind knowing that both are new units.

Failing that the new relays will be ordered and fitted, then after that it will be off to the Auto-electrician to get all the wiring tested and possibly the PCM re-programmed as i dont have the tools to do that.

 

Did you ever find the cause ?, iam having the same problem

 

Yes, got it fixed, found that it was a faulty sensor located on the back of the engine just below the back right hand corner of the 'earth dreams' engine cover. I will see if I can dig out a photo and part number. But it can be a bit hit and miss if it's the right part, as honda themselves say change a different part on the other side of the engine to resolve, have also seen you tube videos say that it's the injectors that causes the issue.

 

Hi Colinn
I am also getting the PGM FI fault code, but only very intermittently. Perhaps once every 6 months it pops up for a few days and then goes again🤷‍♂️. I would be very interested to know more about sensor you fitted?
Thanks
MJ