Tech Tip: GM Vehicle has DTC P0757 Set, MIL Illuminated and Slipping Transmission

Tech Tip: GM Vehicle has DTC P0757 Set, MIL Illuminated and Slipping Transmission

Some customers may comment on any of the following conditions - an illuminated MIL (where DTC P0757 is found as a history code), no third and fourth gear and the the transmission does not shift correctly.

Models affected:
– 2007 and prior GM Passenger Cars and Light Duty Trucks;
– 2003-’07 HUMMER H2;
– 2006-’07 HUMMER H3; and
– 2005-’07 Saab 9-7X
with 4L60-E/4L65-E/4L70-E Automatic Transmission (RPOs M30/M32/M70).

Figure 1Some customers may comment on any of the following conditions:
• An illuminated MIL where DTC P0757 is found as a history code in the PCM or TCM;

• No third and fourth gear;

• The transmission does not shift correctly;

• The transmission feels like it shifts to Neutral or a loss of drive occurs; and/or

• The vehicle free wheels above 30 mph. High rpm needed to overcome the free wheeling.
This condition may be caused by any of the following:

• Chips or debris plugging the bleed orifice of the 2-3 shift solenoid (367). This will cause the transmission to stay in second gear when third gear is commanded and return to first gear when fourth gear is commanded.

• A 2-3 shift valve (368) or 2-3 shuttle valve (369) that is stuck, restricted and/or hung-up in its bore.

This condition may also be an indication of a damaged 2-4 band or 3-4 clutches. This clutch damage may generate debris causing the 2-3 shift valve line-up to stick in the valve body bore and set DTC P0757.

1. Inspect the condition of the transmission fluid for signs of overheat or a burnt odor. If either is noted, the transmission should be disassembled for further investigation and repaired as needed.

See Figure 1.

2. Inspect the inside of the oil pan for signs of clutch friction material. A small amount of friction material in the bottom of the pan is normal. If a large amount of clutch material is noted in the fluid or bottom pan, the transmission should be disassembled for further investigation and repaired as needed.

3. Inspect and clean the 2-3 shift valve (368), the 2-3 shuttle valve (369) and the valve bore of debris/ metal chips.

4. Inspect and clean the 2-3 shift solenoid (367B) opening of debris/metal chips. While inspecting the 2-3 shift solenoid (367B), look for a screen over the solenoid opening. If the solenoid does not have a screen, replace the solenoid. All current GMSPO stock shift solenoids have a screen over the solenoid opening.

5. If clutch debris is found, it is also important to inspect the pressure control (PC) solenoid valve fluid screens. Clean or replace the PC solenoid as necessary. It is also important to flush and flow-check the transmission oil cooler using J 45096.

Refer to SI “Automatic Transmission Oil Cooler Flushing and Flow Test” for the procedure.

Refer to the appropriate service manual for additional diagnostic information and service procedures.

Courtesy of Mitchell 1.

You May Also Like

TPMS: Are Retrofits in Your Future?

Installing a retrofit kit can be performed with the tools and equipment you already own and use on a daily basis.

Tire tread

The contact patch of a tire, the area that touches the ground, is one of the most critical aspects of tire performance, and it affects tire wear, fuel economy, handling, braking, traction, noise and ride quality. In other words, it affects everything, including safety.What’s more important is the contact patch will only be correct if tire pressure is set to the specification provided by the vehicle manufacturer. When overinflated, the immediate safety concerns of handling, traction and braking are affected since the contact area of the tire is reduced, leading to reduced grip.An underinflated tire will also suffer in performance and even though it may seem like a larger contact patch would be better, it’s not. The larger contact patch creates more friction and heat, affecting the rubber compound and changing the characteristics of the tire, leading to negative handling effects, as well as a drastically increased stopping distance.

BendPak to Debut Eight-Armed Car Lift Concept at NADA

Octa-Flex improves technician productivity, convenience and ergonomics, according to BendPak.

Matco’s New Ghost Cart: Where Tools and Style Spookily Align

Haunt your shop with efficiency: Matco’s 2023 Ghost Cart is sleek and functional.

Matco Ghost Cart tool storage
New Cool Boss CB-26: Plug In and Chill Out 

Portable evaporative cooler drops temperature up to 26 degrees at work or play.

Updated Jump-N-Carry 12V Jump Starter, Power Supply

Delivering 550 Start Assist Amps of starting power, the JNC345 can tackle a wide variety of starting tasks.

Other Posts

Maximize Your Scan Tool

Are you maximizing your scan tools to their full potential? Don’t let them be just an expensive code reader.

Scan Tool
Upgrade Your Air System: It’s Easier Than You Think

Improving your shop airflow is only a benefit, unless you like to spend more time, work harder and make less money.

air flow tubes
2024 Is Your Year to Be the Technician You Always Wanted to Be

As we enter 2024, strategic career planning is essential for success in the automotive repair industry.

happy new year 2024
Impact Wrench Technology

Interchangeable anvils are a feature on some new impacts.