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OBD code 37 question

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Old Feb 3, 2021 | 01:37 PM
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OBD code 37 question

I have KOEO codes 37,34 and 63 in memory. Since there is no code 37 in my manual I thought I would check in here before I go chasing the problem.

34 EVR - (O, R, M) EVP sensor is/was high - EVR

63 Throttle Position Sensor (TPS) signal too low TPS

My noticeable issue is when I start the truck the idle will quickly drop down to anywhere between 750 and 850 RPM's. Once I drive and get it to operating temp the idle will stay a fairly steady 1K and not drop down. I did check the FPR and had no gas in the vac line. When I disconnect the IAC nothing changes. Any advice to nail this down is appreciated. Thanks Sandy
 
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Old Feb 3, 2021 | 05:44 PM
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There is no Code 37 that I am aware of. Re-run the KOEO tests and CM display. Watch the flashes a little closer.

Consider investing in a $30 code reader.
 
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Old Feb 3, 2021 | 05:49 PM
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I will have to check in the morning, I have the reader but will double check it again, Thanks Randy
 
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Old Feb 4, 2021 | 08:55 AM
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So Code 37 came up when using your code reader? That's odd.
 
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Old Feb 4, 2021 | 11:11 AM
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After I had run those codes yesterday, I was checking connections and the TPS MAY not have had been totally connected. The retainer clip on the connection is broken but I am speculating about it being the culprit.. I will take care of that in case it was.. Today I got NO codes except 11 pass on KOEO and CM. Took the truck on a short drive and rechecked and still no codes. Then I ran a KOER test and all was clear. The reason I suspect the TPS is because the truck is now idling at 750 and will return lower than before when goosed.
After I ran the first KOEO test and had no codes, I changed batteries in the reader that still showed 1.492 each just to test. Glad I don't have that non existent code 37 that definitely came up on the reader. Thanks Randy
 
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Old Feb 4, 2021 | 03:17 PM
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Originally Posted by sandymane
The reason I suspect the TPS is because the truck is now idling at 750 and will return lower than before when goosed.
A strong indication the TPS may be bad and/or a bad connection.
 
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Old Feb 4, 2021 | 03:23 PM
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Originally Posted by rla2005
A strong indication the TPS may be bad and/or a bad connection.
To make sure I understand, when I say the idle returns lower than before, I mean the idle goes back now to about 800-850 whereas it was 1K.which is why I checked it in the first place. I have a tie wrap around it now and the connection is secure and not going anywhere at this point. Do you still feel it might be bad even with no codes etc.
 
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Old Feb 4, 2021 | 07:12 PM
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Normal idle, engine warm, in drive, brakes applied is going to be 750ish rpm, with no accessory systems creating load. 800/850 rpm is probably within normal tolerance.

If you no longer have a code and good idle, good throttle characteristics it is probably fine. You can check the output voltage, and so forth to see if the sensor is still in spec.

The part that of the connector that would break would probably be the TPS side, so a new sensor would be a fix. You could also get a new connector and swap em out.

If you really want to go down a rabbit hole you could check the baseline throttle stop screw setting.
 
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Old Feb 4, 2021 | 10:17 PM
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As yoy said, I think I am good for now with my idle. If I have any more issues I will test it and replace if necessary, Now with no codes in KOEO or KOER I think I will leave the throttle stop screw rabbit hole for the rabbits. I think that screw got me to FTE in the first place, Anyway all is good for now, Thank you for the advice and help. Always appreciated, Sandy
 
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