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On Board Diagnostics Code 900 1991

Hi Everyone!
Thanks for your help! I got my car running smoothly finally after just recalibrating the Throttle Position Sensor. Anyway, when I ran a OBD check on my 1991 940 GLE w/ a 4 cylinder, 16-valve engine, it gave me two trouble codes (2-3-1 & 2-3-2). What do they signify and how do I correct the trouble codes? Also, I'm looking for a place that could sell me a cheap front driver side parking/turn signal light lens. My car has the integrated fog lamps. Again, thanks for your help and have a great day!

Best regards,
Volvo fanatic








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    try this 900 1991

    Hi

    I had the same problem with my 940 B200F engine. Kept getting the 231 code on the diagnostic.
    A month ago i went down the shops. When I got back to the car, it wouldn't start.

    I couldn't hear the fuel pump run when I turned the key, so i ripped off the fuse box cover by the gearstick and tapped the fuel pump relay (the white one one the left, behind the little ones at the front) and the pump kicked in.

    So when i got home I took the relay out, took the cover off and inspected the solder joints. Some of them had gone dry (around the joint there's a hairline crack) so I resoldered every joint and put it back.

    I've had no problems yet, and the other day I checked the diagnostic codes and it comes back 111 (no problems).

    I looked at a supplier for a pump relay and found the cheapest was £15. To fix it only cost me a bit of solder and the electricity to power the soldering iron perhaps about 40pence. Not a bad difference for a hairline crack!!!!

    So check your relays, and look very closely at the solder joints, it saved me a few quid!!!!!!!








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    On Board Diagnostics Code 900 1991

    Those trouble codes basically tell you that at some point in time the ECU could not achieve an acceptable fuel mix -typically because of an improper air or fuel supply (unmetered intake air, incorrect fuel pressure, dirty fuel injectors) or faulty engine management sensors (AMM or O2 sensor).

    Before you get too worried, always clear the trouble codes and wait for them to re-appear. As you've been having rough running problems that are now cured, the problem may simply have been transitory. An engine will often set these kind of codes if it stalls or dips wildly below normal idle rpm and the TPS switch hasn't been tripped (as in your case).

    Otherwise Greg has put you on the right path. In addition to the possibilities he mentioned (and the IAC valve is indeed an unlikely contributor) you should look carefully for intake air leaks -split/disconnected vacuum hoses (check both ends), idle air bypass hoses, main air supply tube (!!), leaks at the throttle body gasket. Perform a basic test on the fuel pressure regulator as per the FAQ. Before getting too suspicious of a faulty AMM, try thoroughly cleaning the AMM electrical connector with spray contact cleaner and re-packing the female contacts with dielectric grease -do the injector, TPS switch and system relay (radio noise suppression relay) connectors at the same time.
    --
    Dave -not to be confused with a real expert








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    On Board Diagnostics Code 900 1991

    Culprits there could be the fuel pressure regulator, or the AMM, or maybe even the idle air control valve (IACV) though unlikely... Ithink the codes are related to air/fuel mixture.

    See FAQ for codes.

    Seeing as you have the B234f engine, PLEASE inquire about all the timing issues and weaknesses before you need a head rebuild. See FAQ and do internet research.

    Good luck,
    Greg Mustang
    Montreal - Ottawa
    Canada







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