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You asked:
GETTING INTERMITTANT CODE 26 (QUAD DRIVER FAULT) ON 1991 BUICK PARK AVE ULTRA 3.8 L V-6 NO SUPERCHARGER. ONLY THING I SEE OUT OF SPEC IS ONE OF THE SECONDARY COILS HAS 85K OHMS RESTAINCE AND THE OTHER TWO HAVE ONLY 11K. COULD THIS BE IT?
Optional Information: 1991 Buick PARK AVE ULTRA 3.8L V-6 NON-SU
The ignition coils are not controlled by the pcm quad drivers and will not set a code 26
A code 26 sets on your car if the control circuits for one of the following components show an improper voltage reading
Each of these items has ignition voltage applied to them. When they are commanded OFF by the PCM, the voltage on the wire at the PCM should be HIGH (BATTERY VOLTS). When they are commanded ON, the voltage at that pin should drop to near zero volts.
Code 26 QUAD DRIVER will set when the voltage is HIGH when it should be LOW or when the voltage is LO when it should be HIGH.
Possible causes, blown fuses, disconnected components , wiring, connections, PCM .
Does this answer your question? If you have access to a DVOM I can suggest some tests for you.
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Technician/Trainer
28 years experience, Interprovincially Licenced MVMechanic (Canada) , Technical Trainer
Hello and good morning. I see you replied and accepted after I had pushed away from my desk last night.
Thank you for the accept and the positive feedback. That is very much appreciated.
Ok, down to the task. One question before we start please.. how long has this code 26 been there ? As far as you know, has the engine been replaced in this vehicle ?
I'm going to upload an image of the connector at the PCM (powertrain control module). The first step is to , key on, engine stopped, check the voltages at the pins I talked about in the previous post. Print the previous diagram and the one I have uploaded today.
Click here to download an image of the PCM connectors. Please print this for reference.
Please tell me what the voltages are on the pins indicated in the first printout (from yesterday) with the key on, engine stopped.
That was two questions (ha-ha).
The code 26 has been appearing (intermittently) for about 30 days now. After I changed the TPS, set the voltage, and cleared the codes, the 26 started showing up. This is first time ever for code 26.
The engine (I'm glad you said engine, motors are for drills, engines run on fuel !) has never been replaced. I have owned the car since day one, have done most of the repair work myself, had to replace the 4T60E transmission at 235,000. Vehicle has 278,000 on it currently, still has factory compression, but everything that rotates has been replaced several times over the last 17 years.
I was sitting in the driveway key on, engine off and heard this tapping sound. Popped the hood and the solenoid for the purge canister was ticking away. Turned key off, then back on and it was gone. I suspect something wrong going on there.
Will record the voltages from first diagram as you requested and report back to you. It will be a day before I can get that done, unfortunately I am saddled with a job( the curse of mankind).