Code 37 on 1990 Dodge Spirit with 3 Speed automatic

When I check for codes on my 1990 Dodge Spirit, I am getting a "37."
According to the info on Allpar.com, it could be one of the following:

37 Shift indicator light failure, 5-speed
OR
part throttle lock/unlock solenoid driver circuit (87-89)
OR
solenoid coil circuit (85-89 Turbo I-IV)
OR
Trans temperature sensor voltage low (1995 and on; see NOTE 2)

Since it is not a 5 speed, and does not have a turbo, I am guessing it
is the second one, although mine is a 1990 and not a 1989. It was
however, assembled in September of 1989.

Could it have anything to do with the torque converter not locking?

Thanks in advance,

-Kirk Matheson

 

Yep, you've got an open or shorted condition in your torque converter
lockup clutch solenoid circuit. This could be due to a fault, or it
could be because a particular TSB has been applied, which calls for the
deliberate unplugging of the lockup solenoid to eliminate a road-load
surging effect.

The only detrimental effect of an unplugged or nonfunctional torque
converter lockup clutch is a loss of approximately 7% fuel economy at
speeds over 45mph. If getting back that fuel economy is worthwhile to
you, plug the torque converter clutch back in or find and fix the
problem.

The plug is located right next to the transmission fluid dipstick. If
you find it plugged in, try unplugging it, cleaning the contacts on
both the transmission and the socket, and plugging it back in. Clear
the trouble codes by disconnecting the main feed disconnect (located in
the positive battery cable about 7" down from the battery) for a few
minutes -- this is a good opportunity to check and clean that
connection -- and then plugging it back in.

 

--

Before you start looking for open or shorted condition in the lock up
torque converter make sure you have a lock up solenoid. not all
transmissions have this option. sorta like not having cruise control or a/c.
If your vehicle does not have those options and you did the key cycle fault
code check you would get faults for cruise control and a/c. Mr Lite bulb
Stern could have you running is circles if yours is not equipped.
If the vehicle does have it, there is a TSB to jump the connector which will
not allow the Trans to lock up, the only purpose of the jumper is to keep
the fault code from setting.

Glenn Beasley
Chrysler Tech

 

Thank you both for the information. The vehicle did have the lock-up
when it was new. It would usually kick in around 60 MPH. Last October,
a used transmission was installed to replace the original which was a
victim of a botched rebuild job, (not by the same shop).

Anyway, the used one works fine except for the code being set. The shop
checked the numbers to ensure that it would be compatible.

If it has the connector near the dipstick previously described, does it
most likely support converter lock-up?

Thanks,

Kirk Matheson

 

--

Yes, if there is a male connector coming out of the trans it has it.

Glenn Beasley
Chrysler Tech