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BMW E46 Fault Codes P-1188, P1189, P0170, P-0173, M52TU, M54

August 30, 2010

I have a 1999 BMW 323i and the scan code kept coming up p1188/1189 and p0170 and p0173 . What are these codes and how do I correct the the problem?

The P1188 and P1189 codes are for “fuel control” for both banks 1 and 2 (cylinders 1-2 and 4-6, respectively).  The P0170 an P0173 are for “fuel trim”, again, for both banks 1 and 2.

With these codes, I would first look for vacuum leaks in the intake system.  Inspect the rubber boots going from the MAF (Mass Air Flow sensor) to the throttle body, especially the small leg that connects to the idle control valve, down by the throttle body.  Additionally, inspect all vacuum and air handling hoses.  Another common vacuum leak source is the crankcase ventilation system.  See the link below for additional info on the crankcase ventilation system.

If you cannot find any obvious vacuum leaks, you can have the system “smoke tested”.  This injects a smoke into the intake and any leaks will allow the smoke to come out.

Click here for Crankcase Ventilation info and DIY

Click below for intake boots and hoses:

Fault code reader and reset tool:

Bavarian Autosport

  1. Rey Cleto permalink

    Mr Otto
    Thanks for the info on scan codes 1188, 1189, 0173 and 0170. Just got done working on the car this weekend. The hose from the valve cover to the CV Valve was cracked. and the hose going to the dip-stick was cut into two. Thanks! Car is fine now, knock on wood.

  2. Jose permalink

    P-1188, P1189, P0170,0173 and im getting p01250 i’m getting this codes idk what to do i checked everything my fuel pressure check for leaks and nothing!!!=(

    • Have you had a “smoke test” done on the intake system, as noted in the original post? If so, and there were no leaks, have you checked the crankcase ventilation hoses or the oil separator for sludge clogging? Also, what is the mileage on your oxygen sensors? You did not mention what model or year BMW you have, but you likely have a replacement interval (for the sensors) of 80,000 to 100,000 miles.

      Click HERE for oxygen sensors

  3. jose permalink

    i have an 323ci 2000 and it has 150,798 i just did the crankcase and hoses. i change both of front o2 sensors i check the intake, new MAF
    the car shakes alil any ideas?

    • Do you have the CHECK ENGINE light coming on? Have you checked for any stored engine management fault codes (using the tool shown above)? Can you give any more detail on exactly what the symptoms are and under what conditions they occur?

  4. jose permalink

    do you think that a crack in the valve cover could cause this?

    • Yes, a cracked valve cover can cause a vacuum leak … and could result in these types of fault codes.

      We can order you a new valve cover for your BMW model. Just give us a call at 800-535-2002

  5. jose permalink

    I’m mean im getting P-1188, P1189, P0170, P-0173, and i done the ignition coils
    crank case with new hoses
    new MAF
    intake manifold gasket
    gas filter
    spark plugs which
    spark plugs would you recommend? i herd bosh were bad?
    plzzzz any ideas?
    and im using a generic scanner

    • First, the Bosch plugs are one of the best spark plugs you can use …. in any engine. Bosch plugs are original equipment on almost every BMW ever made.

      How many miles do you have on your BMW (what model, as well)?

      Have you replaced the oxygen sensors?

      If you do have a cracked valve cover (as noted in your prior comment), let’s take care of this before going further.

      Just call our agents at 800-535-2002

  6. jose permalink

    yea i think i have a lil crack.. but the car feels like is misfiring? and im not getting misfiring codes.
    yes i have both of the front ones
    my car is a bmw e46 323ci 2000 mp 150,798 and i check my fuel psi and it was at 55?

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