If your scan tool is recording a P0750: Low Reverse Solenoid Circuit Malfunction (if your Chrysler vehicle is OBD II equipped) or a trouble code 41: Low Reverse Solenoid Circuit, and your Chrysler (Dodge or Plymouth) transmission is not shifting out of 2nd gear, then you've come to the right place to test the Low Reverse Shift Solenoid.
Contents of this tutorial:
- Symptoms Of A Bad Low Reverse Shift Solenoid (DTC P0750).
- What Tools Do I Need?
- Where To Buy The Chrysler Solenoid Pack.
- Circuit Descriptions Of The Chrysler Transmission Solenoid Pack.
- TEST 1: Low Reverse Shift Solenoid Resistance Test.
- Low Reverse Shift Solenoid Test Conclusion.
- Chrysler Transmission Solenoid Pack Tutorials.
You can find this tutorial in Spanish here: Cómo Probar Código P0750 (Solenoide De Cambio A) (at: autotecnico-online.com).
Symptoms Of A Bad Low Reverse Shift Solenoid (DTC P0750)
When the Low Reverse Shift Solenoid (also known as Shift Solenoid A), inside the transmission solenoid pack, goes bad, you're gonna' see two specific symptoms, these are:
- The check engine light (CEL) will be shining nice and bright on your instrument cluster.
- If OBD II equipped, You'll have P0750: Low Reverse Solenoid Circuit Malfunction stored in the TCM's memory.
- Depending on the type of scan tool you own, this code can be translated as: P0750: Shift Solenoid A Malfunction (OBD II equipped only).
- If OBD I equipped, you'll see trouble code 41: Low Reverse Solenoid Circuit.
- The transmission will not shift gears:
- More specifically, it'll stay in 2nd gear no matter what speed you're driving the vehicle.
- This is called in tech terms: Limp In mode.
It stinks that you're having this issue (P0750 or Code 41), but the cool thing is that it's not that hard to test this yourself and replace the solenoid pack if indeed the Low Reverse Shift Solenoid is bad.
What Tools Do I Need?
The most important tool that you're gonna' need is a multimeter. Your multimeter can either be a digital multimeter or an analog multimeter.
A scan tool really isn't needed to actually test the Low Reverse Shift Solenoid, but it does come in handy when it comes to checking for diagnostic trouble codes (especially if your Chrysler vehicle is OBD II equipped and you're not able to manually extract the trouble codes).
Here are some of my suggestions:
- Multimeter
- Don't have one or need to upgrade your analog multimeter to a digital multimeter, check out my recommendation here: Tekpower TP8268 AC/DC Auto/Manual Range Digital Multimeter (Amazon affiliate link).
- Scan Tool
- As I mentioned above, you don't need to use a scan tool to take advantage of the test info in this tutorial, but it does come in handy to read any trouble codes.
- If you don't own a scan tool yet, this it the one I recommend: ZM301 OBD2 Scanner Diagnostic Tool (Amazon affiliate link).
Where To Buy The Chrysler Solenoid Pack
Your local auto parts store (like AutoZone or O'Reilly Auto Parts) will carry the Chrysler solenoid pack and will be more than happy to sell you one at a cost of US$150 to $200, which is quite expensive.
Another alternative you may want to explore, is buying the transmission solenoid pack online and saving a few bucks. Below, you'll find two links (to the same place) so that you can shop and compare and see what option is best for you!
Disclosure: As an Amazon Associate, I earn from qualifying purchases. Buying through these links helps support this site at no extra cost to you. Thanks for your support —it really means a lot!
Circuit Descriptions Of The Chrysler Transmission Solenoid Pack
Now, just in case you're not aware, the Low Reverse Shift Solenoid (Shift Solenoid A) is part of the transmission coil pack (this also means that if your tests indicate it's bad, you'll need to buy the whole solenoid pack to solve the problem).
The transmission coil pack is bolted to the transmission (see the photo at the top of this page). A connector with 8 wires connects to the solenoid pack.
2 of those 8 wires are the ones that feed power and the activation signal to the Low Reverse Shift Solenoid and in this section, I'll identify them for you. This is info you'll need to know to test the solenoid.
| Chrysler Solenoid Pack Connector Pin outs | ||
|---|---|---|
| Pin | Wire Color | Description |
| 1 | Yellow w/ Black stripe* | 2-4 Pressure Switch |
| 2 | Dark Green* | Low/Reverse Pressure Switch |
| 3 | Orange w/ Black stripe* | Overdrive Pressure Switch |
| 4 | Red* | Power (10 to 12 Volts DC) |
| 5 | Pink* | Underdrive (UD) Solenoid |
| 6 | Brown* | Overdrive (OD) Solenoid |
| 7 | Light Blue* | Low/Reverse Solenoid |
| 8 | White* | 2-4 Shift Solenoid |
* Your specific Chrysler, Dodge, Plymouth vehicle may have different colors.
One last thing before we move on to the next page (and start testing), the solenoid pack will have the above 8 numbers embossed on it. This will further aid you in identifying the metal male terminals you'll need to test in the next page.
TEST 1: Low Reverse Shift Solenoid Resistance Test
OK, to get this show on the road, I'm gonna' ask you to check the resistance of the Low Reverse Shift Solenoid (Shift Solenoid A) and as mentioned in the previous page, this bad boy is part of the solenoid pack.
We'll accomplish the resistance test by directly probing the round metal male terminals, of the solenoid pack, with your multimeter's leads (and in Ohms mode). The pins that you're gonna' test are the solenoid pack's pins #4 and #7.
Remember, Pin #4 is the one that feeds power (10 to 12 Volts) to the Low Reverse Shift Solenoid. Pin #7 is the one that feeds the activation signal from the PCM (or TCM).
NOTE: Let your vehicle cool down if you have been running the engine for an extended period of time or you run the risk of serious burns if you test the Low Reverse circuit with a hot engine.
If the engine/transmission are hot, let them cool down for about an hour. Be careful, use common sense and think SAFETY.
OK, this is what you'll need to do:
- 1
Disconnect the transmission's solenoid pack's electrical connector.
If you already have it off of the vehicle, well that's OK too, since it'll be that much easier to test pins #4 and #7. - 2
Place you trusty multimeter in Ohms mode.
- 3
Probe the metal male terminal labeled with the number 4 with the red multimeter test lead (see photo above).
- 4
Probe the metal male terminal labeled with the number 7 with the black multimeter test lead.
- 5
Your multimeter will register between 0.5 to 9 Ohms if the Low Reverse Shift Solenoid is OK.
Let's analyze your test result:
CASE 1: The multimeter registered the indicated Ohms. This is good and the expected test result, which of course let's you know that the Low Reverse Solenoid isn't fried.
Since a trouble code P0750 is lighting up the check engine light and the transaxle is not shifting out of 2nd gear, the next steps are:
- Check the continuity of circuit #7 between the Transmission Control Module (or PCM depending on how it's set up on your vehicle) and the solenoid pack's connector.
- Check the physical condition of the solenoid pack's electrical connector and the round metal terminals inside of it for damage.
The above steps are beyond the scope of this article, but at least now you know what direction your troubleshooting needs to take.
CASE 2: The multimeter DID NOT register the indicated Ohms. Double check that you're testing the correct metal male terminals on the solenoid pack and retest.
If you still don't see the indicated resistance in Ohms, then the Low Reverse Shift Solenoid is bad. You'll need to replace the solenoid pack assembly to resolve the problem.
Low Reverse Shift Solenoid Test Conclusion
The Chrysler solenoid pack is an item most Chrysler (Dodge or Plymouth) vehicles will need to get replaced sooner or later. Over the years, working as diagnostic tech in an automotive repair shop, I've replaced quite a few of them, so in this section, I want to share a couple of personal suggestions that I think will help you:
- Whenever any of the shift solenoids, inside the solenoid pack, go bad, the transmission will go into LIMP IN mode. This means the transaxle will stay and run in 2nd gear only.
- A bad Low Reverse Shift Solenoid will not cause your transmission to slip.
- If your vehicle's transaxle is slipping, then replacing the solenoid pack will not help since slippage is a direct result of internal transaxle damage (burned clutch discs, broken/worn internal hard parts, etc).
- Can a bad solenoid pack cause the transaxle to go bad?, the answer is YES if you don't take care of the problem as soon as possible and/or continue driving it for extended amounts of time/distance in LIMP IN mode.
I hope this test tutorial helped you.
Chrysler Transmission Solenoid Pack Tutorials
The following tutorials relate to this transmission solenoid pack tutorial:
- How To Test Diagnostic Trouble Code P0755 (2-4 Shift Solenoid Malfunction).
- How To Test Diagnostic Trouble Code P0760 (Overdrive Solenoid Malfunction).
- How To Test Diagnostic Trouble Code P0765 (Shift Solenoid D Malfunction).
If this info saved the day, buy me a beer!
