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Service stabilitrak codes P228C, P0089, P0171, P0174

6K views 8 replies 5 participants last post by  caddy 
#1 ·
My wife's car went into limp mode on our way to drop off our son at college this week. Limped the way home 2 hrs away. From my scanner was able to retrieve those codes. Measured fuel pressure at shrader valve on fuel line at 70 psi upon startup. Replaced fuel sensor thinking it was the regulator from online search and a youtube video. That was my mistake, I did an online search and the fuel pressure sensor came up as a regulator. When I called the dealer and asked for a fuel pressure regulator they sold me the fuel pressure sensor on the fuel rail. I didn't realize my error until after I replaced it. So going forward I used my scan tool to pull a freeze frame of code 228C. It shows FRP which i think is fuel rail pressure at 414kPa. Which translates to like 70 psi. From what I read that is way too low. So I started the Acadia and did the datastream while running after the fuel sys1 and 2 were in the closed position. The FRP showed 507kPa which is about 73 psi. So then I disconnected the high pressure pump plug and ohmed it out. It ohmed out .6 ohms and OL to ground so It passed the test procedure in the troubleshooting manual. Next I started the Acadia and left the plug off while I had my multimeter on the plug to test voltage. It was at 12V upon startup and then went up to 14 volts. So it seems like the electrical side to the high pressure pump is operating properly. I am thinking I need to replace it as it is not building up fuel pressure. I am thinking it is a mechanical issue with pump. Would like feedback from a mechanic before proceeding with ordering of pump and two fuel lines as they are not cheap. Thanks in advance.
 
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#2 ·
No response from anyone. smh
Update:
I was confident in my troubleshooting so I ordered the high pressure fuel pump and two lines from Amazon due to dealer wanted over 450 just for the pump. I got all parts under 300. The pump and lines from amazon. Once they arrived i noticed the new pump did not come with a gasket so I went to Autozone and picked one up. I also picked up a fuel line removal tool for like 9 bucks. The car had not ran in a couple of days. So first I disconnected the low pressure line and didn't get much fuel out of the line. So then I loosened the high pressure line and no fuel came out. Next I removed the pump. The cam roller fell out while I was getting the new pump ready. It got dirty with sand so I cleaned it with contact cleaner and then oiled it with the oil that came out of old pump. I installed roller back in and then installed new pump. Next I installed the new lines and reconnected fuel hose. Finally I connected the pump plug and proceeded to start the Acadia. Immediately it started up fine and the service stabilitrak light went away. The service engine light is still on. After research of service engine light. It states on a permanent code only the modules can erase it and it cant be done with a scanner or by unplugging the battery. So I just need to run it. I took it for a test drive and it accelerated immediately. As an added side note my scanner did not read the fuel pressure properly as it did not change after the repair. I have a cheap scanner so that may be the case. its a thinkobd 100. So wife's car is back online.

Updating post incase it helps others.
 
#4 ·
#5 ·
Well the repair didn't last long. The light came back on. Took it to a mechanic to scan and he said it looks like the high pressure fuel pump is bad. I told him i replaced the pump and sensor. He showed me the Snap on scan tool and said everything checked out ok with all his tests. He cleared the code and said to just put some fuel injector cleaner in tank. I took truck and about an hour later the service engine light came back on. SMH code 228C. Any suggestions? I dont have a high dollar scanner to measure pressure of fuel rail. So its either return the pump and get the OEM from dealer or take to dealer for testing.
 
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