Hello! I am a young volvo owner. My dad bought a 2004 volvo s60 2.5t about 10 years ago. It had CEL one which gave code p0089 (Fuel Pressure Regulator 1 Performance). He then garaged it for about 8 years (not the best decision lol) and gave it to me about 2 years ago. After giving it some TLC , it was able to pass CA smog and I made it my daily driver soon after. During that time,I noticed that my car would never start on the first attempt (especially when cold), would idle pretty roughly at times (would never shut down though), & get bad mpg (13 mpg). I eventually replaced the spark plugs & 2 ignitions coils. It helped the car run a bit smoother but the starting problem still persisted. About a year ago I had the fuel pressure regulator (p/n 31272730) replaced cuz the CEL (p0089) was on. About a week later, the CEL came on for the same code. Personal volvo mechanic said the recently changed fuel pressure regulator was probably faulty & replaced it with another one (current one). A couple days, later the same code returned. I realized that the fuel pressure regulator wasn’t the problem. I replaced the fuel pump assy (p/n 30792879) weeks later. That fixed the starting issue, idling issue, & mpg. Fast-foward to a couple weeks ago, the CEL came on but for two codes : p0089 & p2188 (System too Rich at Idle Bank 1). I’ve received the p2188 code before as well but not as frequently as p0089. I cleared the codes with my cheap scanner and days later only p0089 code returned. I also noticed that fuel guage was rather inaccurate & erratic. Many times the “miles to empty” will go from “--” to 45 then back “--” & then to 20. It’s gotten to a point where I don’t rely on it anymore (I just reset trip computer & multiply mpg by purchased gallons). I have been driving more often with near empty tank lately (range is always “--” when I refill) because of gas prices lol. As of right now, my car still has the p0089 code.

After doing some research in volvo forums(not sure if it was the right research lol), I decided that I needed a new fuel filter (p/n 30620512) ,PEM module(p/n 30742823), & Fuel level sending unit (p/n 8683142). I called the dealer, gave them my vin & they gave me the p/n listed above. I looked up the p/n online & saw that the fuel filter (p/n 30620512) is only for s60s with plastic fuel tanks. My volvo has a steel/metal fuel tank because the fuel pump assy (p/n 30792879) is specifically for steel/metal tank volvos. This confused me so I did some research & found that Volvos with steel/metal tanks don’t have an external fuel filter. So I ruled out needing the fuel filter. However I looked up the p/n for my fuel pump assy & noticed that it comes with a fuel level sending unit integrated in.

Does this mean that I should rule out buying the standalone fuel level sending unit (p/n 8683142) or does my car have two sending units?

Also what do you recommend that I that will help in removing code p0089 & potentially p2188? Will replacing the PEM module help? I heard the PEM modules in some volvos can corrode & be very faulty.

P.S.
The amusing thing about alot of this is that my car drives completely fine. I dont experience bad mpg, misfiring, stalling, loss of power, really rough idling, etc. The car is completely fine to drive.

 

Before you start dropping $$$ on new parts, you probably should do some testing. For starters - why would you think you need a new fuel filter? are you getting low fuel pressure at the pump? You mentioned the PEM and fuel pressure regulator but no mention of a fuel pressure sensor. You need to know which kind of fuel pump your car has as volvo went to the variable pressure pumps in the early 2000s. The older design has a fuel pressure regulator to manage pressure at the rail, the newer design has a fuel pressure sensor that send a signal to the pump electronic module (PEM) that in turn controls the pump pressure. So what I'd do is a) research what your car's design is b) do some testing with a fuel pressure guage to see what the pressure is prior to a cold start, immediately after the code start and then after the car has been idling and able to rev. Next, check out this vid on how to find/test/replace the fuel pressure sensor - which is what the P0089 code is pointing to. The P2188 is a rich fuel trim at idle code - which I'd ignore until you sort out the fuel pressure diagnosis.