Code P1620

Tiny
TECKUS
  • MEMBER
  • 2001 BMW 325I
  • 2.5L
  • 6 CYL
  • 2WD
  • MANUAL
  • 120,000 MILES
I plugged in my OBDII scanner and told me the code P1620 is for Thermostat Circuit High or something like that for my BMW. I don't know if this has to do with the fact that I don't have a Crankshaft Position sensor in or not, but I don't see any symptoms of thermostat doing anything wrong. After driving the car back home about an hour and a half, the temperature was a little bit over half, accelerates perfectly. I'm just wondering if I should look into this ASAP or leave it until I get my CKP and put it in then see if it still does it?
Sunday, March 31st, 2019 AT 1:48 PM

5 Replies

Tiny
JOETECHPRO
  • MECHANIC
  • 705 POSTS
Hey TECKUS,

The P1620 code is in relation to the control of the thermostat.

Your engine is fitted with an electrically controlled MAP thermostat.

The control system opens the thermostat early in certain situations but otherwise the thermostat operates as a normal thermostat would.

It will not be operating as efficiently as it could but it will not cause you a problem if the engine is not overheating the thermostat is still working.

This could be connected to you CKP if it is not plugged in it looks like they share a power supply.

I would get the CKP fixed and then retest.

Let us know how you go.

I have attached the wiring diagrams for your engine controls if you need them.

Hope that helps.

Regards, Joe
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Sunday, March 31st, 2019 AT 6:25 PM
Tiny
TECKUS
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  • 5 POSTS
Okay, thanks. The CKP should be here soon and if I don't make another update within a week I wont make a reply.
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Sunday, March 31st, 2019 AT 6:30 PM
Tiny
JOETECHPRO
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  • 705 POSTS
Hey TECKUS,

Hope it all goes well. If you can update us on whether the CKP gets rid of the thermostat code that would be really useful for us to know.

Regards, Joe
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Sunday, March 31st, 2019 AT 7:31 PM
Tiny
TECKUS
  • MEMBER
  • 5 POSTS
Okay, I will do that for sure, thank you.
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Sunday, March 31st, 2019 AT 7:38 PM
Tiny
JOETECHPRO
  • MECHANIC
  • 705 POSTS
Hey TECKUS,

Thank you, best of luck with the repair.

Regards, Joe
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Monday, April 1st, 2019 AT 8:09 AM

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