Common Problems and Troubleshooting for the 4T45E Transmission

Posted by on Wednesday, January 30th, 2013

The 4T45E is an automatic transmission made by General Motors. It is an electric four speed trans-axle used is vehicles weighing up to 4500 pounds. The transmission is sometime also referred to as the MN5. It was first introduced in 2005 and remained in use through the 2010 model years. The 4T45E transmission could be found in the Chevy Cobalt and Malibu, the Pontiac Pursuit and Grand Am, and the Saturn Ion and Vue. It was mainly used behind the 3 – 3.5 liter V6 engines, although it did find its way behind a few four cylinder engines.


4T45E Automatic transmission

Source: Google

The 4T45E does have a few issues that owners should be aware of. Let’s take a look at some of the more common problems.

The “E” in 4T45E stands for electronic.

That means this transmission is packed with electronics. The most common failure related to electrical components is the failure of the solenoids. The transmission will have one solenoid for the 1-2 shift, one for the 3-4 shift and one for the lock up torque converter. There are a couple ways to check a solenoid to see if it’s working correctly. The first one is to use an ohm meter to check for resistance. Refer to the shop manual for correct ohm readings. If the ohm reading is too low it means the wires inside the solenoid that make up the electric magnet have shorted out somewhere. If you get no reading that means there is a break in the wire. In either case the solenoid in question will need to be replaced. The other method to check the condition of the solenoids is to use a hand held tool that connects to the OBD-II port under the dash. The tool will run a few basic tests and return a code if it finds anything wrong.


Electrical Componets of 4T45E Automatic Transmission



Another common problem is lack of transmission service.

The owner’s manual recommends that you can go 100,000 miles between transmission oil and filter changes. I don’t think this is the best advice and would recommend that you change the fluid and filter in your transmission every 30,000 miles.

The transmission shifter can work erratically or even not at all.

This is often accompanied by the engine warning light coming on. Most of the time this problem can be traced back to a bad sensor somewhere. The sensor may be in the transmission or in the engine. You need to remember that the computer takes data collected from sensors in the motor to use to calculate when to shift the transmission. So even if the sensor is on the motor, and not on the transmission, it could still be causing a problem.


Oil fill plugs on the 4T45E Automatic Transmission



Automatic transmissions are not meant to last forever. In the event that your transmission has made its last shift, I recommend replacing it with a re-manufactured unit. A re-manufactured unit is as good as a brand new transmission and will also include, in some cases, modifications that will make the transmission last longer. A re-manufactured transmission also comes with a much better warranty: three years compared to 90 days for a rebuilt transmission.

2 Responses to “Common Problems and Troubleshooting for the 4T45E Transmission”

  1. [...] The 4T45E is a fairly decent transmission when not subject to too much abuse. Like any other parts on your car, the transmission has a finite life span. When the time comes to replace the transmission I highly recommend going with a re-manufactured unit. They differ from a simple rebuild in that they bring all spec up to what they were when the transmission was new. A rebuilt transmission will only have the worn items replaced. [...]

  2. corey says:

    transmission will not go into park and it is not the leakage On the out side of the tranmission. I think it is in the leakage inside the transmission? if someone can help me with this problem or help me find stumatics on this transmission 4T45-E. I would be grateful.

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