I had my DTC codes read today and had a code that i dont know
it is on a 1998 monte carlo with a 3.1


Transient DTC P1665
Driver 3
Line 5


i have no idea what this means if anyone can help i would be thankful

thanks justin

 

Haynes says " Evaporative emission control system, purge valve solenoid control circuit"
What that means, I don't know.

 

Did you have your codes read because your "check engine" or "service engine soon light" was on?? The reason that I asked is that DTC P1665 will not turn on any lights. If you have a light on it is for a different reason. Getting back to the P1665,this DTC indicates that your PCM has detected an improper voltage on the PCM output circuit that controls the Evap system Vent Solenoid. This can be caused by a faulty PCM(least likely cause),a problem with the Evap vent solenoid power or control circuits or a faulty Evap vent solenoid.Your vent solenoid is located inside the left rear quarter panel behind the wheelwell splash shield.Power is supplied to it whenever the key is on through the pink wire and the PCM controls the vent solenoid through the white wire by supplying the ground path.The following info is directly from GM Service Information..........
[hr]


DTC P1665 Evaporative Emission (EVAP) Vent Solenoid Control Circuit [/align]



Circuit Description
Output Driver Modules (ODMs) are used by the PCM to turn on many of the current-driven devices that are needed to control various engine and Transaxle functions. Each ODM is capable of controlling up to 7 separate outputs by applying ground to the device which the PCM is commanding on. Unlike the Quad Driver Modules (QDMs) used in prior model years, ODMs have the capability of diagnosing each output circuit individually. DTCP1665 set indicates an improper voltage level has been detected on the output circuit which controls the EVAP canister vent valve.
Conditions for Setting the DTC[align=left]



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The ignition is on.[/align][align=left]



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An improper voltage level has been detected on the output circuit which controls the EVAP canister vent valve.[/align][align=left]



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The above conditions are present for at least 30seconds.[/align]
Action Taken When the DTC Sets [align=left]



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The PCM will not illuminate the malfunction indicator lamp (MIL).[/align][align=left]



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The PCM will store conditions which were present when the DTC set as Failure Records data only. This information will not be stored as Freeze Frame data.[/align]
Conditions for Clearing the MIL/DTC[align=left]



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A History DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.[/align][align=left]



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The DTC can be cleared by using the scan tool Clear Info function.[/align]
Diagnostic Aids
Check for the following conditions: [align=left]



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Poor connection at PCM or the EVAP canister vent valve.[/align][align=left]




Inspect harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and poor terminal to wire connection.[/align][align=left]



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Damaged harness.[/align][align=left]




Inspect the wiring harness for damage. If the harness appears to be OK, disconnect the PCM, turn the ignition ON and observe a voltmeter connected to the EVAP canister vent valve control circuit at the PCM harness connector while moving connectors and wiring harnesses related to the EVAP canister vent valve. A change in voltage will indicate the location of the malfunction.[/align]Reviewing the Fail Records vehicle mileage since the diagnostic test last failed may help determine how often the condition that c

 

yes i had it checked cause the light is on but also i have been having some shifting problems i had a bunch of history codes and that was the only new one on there i am going to have the codes reset and see what new codes come up i dont think it is the trans cause most of the time it is fun just in the morning really has it been doing this but i do let my car warm up before driving i am just trying to eliminate the causes

 

I've read this on a few other forums. Usually all you need to do is take off the gas cap and put it back on.

May need to run through a cycle of gas before this clears out.

 

i found the problem it was my TPS which was making my car shift funny