Most Common Saab Transmission Problems

Have troubles with your Saab transmission? Learn the most common problems, how to troubleshoot the problem, and the possible solutions to fix the problem by reading the guidelines below.

Saab 9-7 vehicles have a 4L60E 4-speed automatic transmission, which can suffer from problems when shifting to higher gears. Sometimes, the transmission will only shift to the 2nd  gear, while the 3rd and 4th gear will not be available. An even more severe problem is when the transmission stays stuck in 1st only, losing the ability to engage other forward gears and reverse. The problem can be intermittent or constant and usually does not trigger warning lights.

Possible causes and solutions: 

• Excessive wear of the 3rd-4th gear clutch pack prevents the engagement of the 3rd gear. This is a common problem due to a fluid leak in the piston that engages the clutch. Aftermarket upgraded kits are available. 
• Damage to the drive shell collar or excessive wear of collar splines prevents gear changes and limits the transmission to 1st gear only. Usually, this will happen suddenly and will remain that way even when the car cools down. Drive shell renewal is the only way to fix this issue.

No reverse after overhaul

First-generation Saabs 9-5 that use a 50-40/42LE 4-speed automatic transmission can experience reverse loss after the transmission has been removed and refitted to the vehicle. In most cases, it will not engage reverse gear when selected from neutral but works if the gear lever is quickly moved from drive to reverse.

Possible causes and solutions 

• A common problem is mismatched connectors for turbine and output speed sensors. This is a common mistake because these sensors have similar connectors nearby. This prevents the engagement of reverse gear, as TCU registers turbine speed as transmission output speed. The easiest way of testing is to disconnect the turbine sensor and see if this affects reverse gear engagement.

Delays during gear shifts

Saab 9-7 vehicles have a 4L60E 4-speed automatic transmission that can suffer from intermittent gear shift issues. Usually, this will show delayed or failed gear upshifts while accelerating. Sometimes, the transmission will fail to downshift during accelerations or when slowing down. These issues usually trigger the check engine light; a corresponding error code will be stored in the vehicle’s DTC memory.

Possible causes and solutions: 

• The throttle position sensor is faulty and sends false data to the TCU. In most cases, ECU will recognize this and trigger a check engine light. Most diagnostic tools can monitor the operation of the throttle position sensor.
• Excessive wear within the TCC regulator valve, resulting in harsh shifting from 1st to 2nd gear. If this happens, the check engine light will be illuminated, and there will be a P1870 code stored in DTC memory. As this is a fairly common problem, many rebuild kits have upgraded components.

Shift flares and harsh downshifts.

Many Saab vehicles use a 5-speed automatic transmission designated as Aisin AW55, which can develop into a common issue. Drivers experience symptoms like shift flares that occasionally happen on accelerations or harsh downshifts. This affects shifts between the 2nd and 3rd gear. This issue will be more noticeable initially while the car is cold but gets more severe with time. Other symptoms include an illuminated check engine light, meaning a trouble code will be stored in the DTC memory.

Possible causes and solutions:

• Excessive wear inside valve body bores results in transmission fluid pressure drop. In some cases, depending on the position of the wear, this can obstruct the valve movement. The cause of this issue is that the material for the solenoid valve material is harder than the valve body itself. When examining the valve body, check for wear marks and replace them if there are any.
• Mismatched control valves during transmission repair. As there are two different variants with or without a control spring, this can result in sporadic 2-3 gear shift issues.

Shift flares on moderate acceleration

Later, Saabs 9-3, with a 6-speed automatic transmission designated as AWTF-80, can develop an issue manifesting as a prominent shift flare. This will usually only happen on mild accelerations, while more aggressive ones will go without this problem. Sometimes, there will be a noticeable delay when coming to a stop. Usually, there will be no other symptoms.

Possible causes and solutions 

• Neglected transmission service intervals result in degradation of transmission fluid and clogged filter, caused by lack of fluid changes. This happens because the manufacturers recommend that this ‘sealed for life’ transmission does not need any fluid changes. High-mileage cars can cause issues that a thorough transmission fluid flush can solve.
• Excessive wear of bores inside the valve body causes intermittent losses of transmission fluid pressure. Being a common and well-documented issue, many transmission specialists offer rebuilt units with upgraded components.

These are some common Saab transmission problems. Note that just because you own a Saab does not mean that you will experience any of these problems.

If you are experiencing a problem with your Saab transmission, call the dealer or use a VIN decoder to determine which transmission is installed in your car. Then, research the problems that affect that particular transmission.

We hope you find the Most Common Saab Transmission Problems guide helpful. Check these troubleshooting and repair guides for more help on your Saab.