Question about 1991 Buick Century

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I have a 91 Buick century 3.3l that is reading out check engine codes 12,26,27,44. I can't find a chart anywhere that tells me what the codes mean. Can you help me out? Thanks, Joe

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I'll try and help with a few of your codes, code 12, will show if the diagnostic term is grounded to access codes, it will show any time that is done and the engine not running, all other codes will show after. The 26, 27 codes have to do with the engine over heating or a coolant sensor. #44 has to do with you Ox sensor, indicates a lean running condition. Pos. due to engine running hot. .

Posted on Oct 08, 2010


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SOURCE: 91 buick century code 44

code 44 is a engine running lean code it is caused by either a vaccum leak,leaking fuel injector,clogged fuel filter,low fuel pressure,or a bad oxygen sensor.

Posted on Jun 02, 2011

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I have a 91 Buick Century limited 3.3L with a 3300 engine. I ran a diagnostic scan of which produced the two-digit codes 12, 26, and 27, and In attempting to look up these codes, I found a website on...

DTC 26 and 27 refers to a QDM (Quad Driver Module) fault.
The Quad Driver is a "safety valve" for the ECM controlled circuits, the quad driver controls up to 4 circuits.

There are multiple quad drivers in the ECM. The QDM shuts down a shorted circuit to prevent high current flow from damaging the ECM. So the DTC 26 or 27 will isolate the problem to 1 QDM. You will need a repair manual with electrical diagrams and DTC flow charts to determine which of the circuits controlled by that QDM are failing.

Usually DTC 26 refers to the Torque Converter Clutch solenoid and related circuit. Most likely you have a shorted TCC solenoid or the harness connected to it, The solenoid is internal in the transmission accessible from the side cover.

Also, keep in mind the single most cause for any code will be a power or ground problem. Clean all the battery cables, and any and all cables or wires that attach from the engine to the firewall.

Hope this helps; also keep in mind that your feedback is important and I will appreciate your time and consideration if you leave some testimonial comment about this answer.

Thank you for using FixYa, have a nice day.

Nov 28, 2011 | 1991 Buick Century

2 Answers

Got trouble codes for 1991 buick century po12 po34 po 45 po 48 wat does that mean and give me the remedial action for that

91 is OBDI not OBDII. The codes are just 12, 34, 45, and 48. 12 - diagnostic mode 34 - MAF/MAP sensor low voltage 45 - Oxygen sensor rich. 48 - not sure on that one What engine do you have? Are there any symptoms? Ill get you some more info once I know what engine.

Sep 26, 2011 | 1991 Buick Century

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91 buick century code 44

code 44 is a engine running lean code it is caused by either a vaccum leak,leaking fuel injector,clogged fuel filter,low fuel pressure,or a bad oxygen sensor.

Jun 02, 2011 | Buick Century Cars & Trucks

1 Answer

My buick century check engine soon light is on...and its making bumping noise and accelarates a point where the bumping noise gets louder...any answers?

Get the codes pulled. The check engine soon light means there is a issue that needs to be addressed. Once you have the codes pulled you can use them to diagnose and locate the issue.

Dec 30, 2010 | 1996 Buick Century

1 Answer

2003 Buick Century Sevice Engine light

A check engine light doesn’t always mean a big problem or an expensive repair is ahead. However, driving a car with the check engine light on could mean that you are doing further damage to the engine, depending on the problem. It’s always best to get the vehicle checked at your earliest convenience.

Because there are so many possible reasons for the check engine light to come on, pulling the codes for the event can be helpful when the problem is not immediately evident. Even if the check engine light is only on a short time, a code will be stored in the ECU for later retrieval.

I suggest scannin your ECU to know which fault code there.

Hope helps (remember rated this).

Jul 01, 2010 | 2003 Buick Century

2 Answers


no but a low fluid level could cause a slip telling the ecm there is a slip top it off then clear the code and drive a few miles if this code comes back i would say there is internal damage to the tranny

May 05, 2010 | 1997 Buick Century

1 Answer

I have a 2003 buick century and the service engine soon light came on as i was driving it what could be the problem pryor to that the anti lock light was on ans also the security light

service engine light refers to a computer related problem. you will need to access the computer link,retrieve the code that turned the light on, and follow a flow chart to diagnose

Feb 12, 2010 | 2003 Buick Century

1 Answer

Coolant low light on and check service engine

If your coolant low light is on it usually means you need to add coolant to the plastic reservoir, but if the coolant level is ok in the reservoir but the light still stays on then the coolant level sensor in the reservoir is not functioning properly. The check service engine light can mean anything from serious engine problems to a simple oxygen sensor reading that the computer didn't like. You can stop by your local auto parts store and they will read the codes and tell you exactly why it is on and what the computer has detected.

Nov 16, 2009 | 1998 Buick Century

1 Answer

Service engine soon lite is on what is the problem to look for.

You need to bring the car to a parts store to have the codes read to help determine why the light is on. This is a free service. They will plug a hand held scan tool into your car's diagnostic port, and read any codes present to determine what is wrong. They can tell you what the codes mean, and suggest ways to fix it. Write down the code #'s and post them here if you have any questions.

Oct 15, 2009 | 2002 Buick Century

1 Answer

91 buick coolant/water pump problem

You have a bad heater core!!

Sep 14, 2009 | 1991 Buick Century

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