Tech Tip: Transmission Slips in Buick Lacrosse – UnderhoodService

Tech Tip: Transmission Slips in Buick Lacrosse

Most of the time, cleaning the sensor elements with a cotton swab and electrical contact or MAF cleaner will fix an incorrect MAF signal and allow transmission line pressure to return to normal.

Vehicles affected: 2005-’07 Buick Lacrosse 3.6L and 3.8L

Symptom: Transmission slip, transmission slip codes, transmission fluid burnt, low transmission line pressure, transmission failure.

Problem: The mass air flow (MAF) sensor elements may be dirty and causing lower than expected engine load calculation.

Test & Fix:
Determine if the vehicle is equipped with a MAF sensor. If the MAF sensor elements are coated with contaminants, such as oil and/or dirt, then the Powertrain Control Module (PCM) will not receive correct airflow/load input from the MAF sensor.

This usually causes a lean air/fuel condition, but also is known to cause lower than expected transmission line
pressure.

Most of the time, cleaning the sensor elements with a cotton swab and electrical contact or MAF cleaner will fix the incorrect MAF signal and allow transmission line pressure to return to normal.

GM has a bulletin, #04-07-30-013B, related to this condition, but refers only to aftermarket air filters as the cause. Many vehicles have been confirmed to have this condition with an OEM air filter.

Courtesy of Identifix, Inc.

You May Also Like

Castrol Turns 125, Debuts New Market Strategy

As part of the new strategy, Castrol will explore opportunities in battery thermal management, digital and service solutions and data center immersion cooling.

Castrol, a lubricant company part of the bp group, is celebrating its 125th anniversary in 2024 To mark this milestone, Castrol is introducing a new strategy titled "Onward, Upward, Forward" to address evolving customer needs, along with a special 125-year commemorative logo for use in worldwide events and sponsorships throughout the year.

Tensioner Tech Assist

The Lift and Pin is designed to simplify tensioner replacement and belt installation. This video is sponsored by Litens.

Detecting Misfire And Knock Conditions

Knock sensors are mounted on the block near the base of the cylinder head.

Ignition System Do’s and Don’ts

Why do ignition systems give technicians problems when diagnosing ignition-related misfires? The answer is that some technicians use tests that might give inconclusive results or do damage to the coil or drivers inside a module.

GM, Honda Begin Volume Production of Fuel Cell Systems

GM and Honda will produce fuel cells that will be two-thirds less expensive compared to Honda’s 2019 Clarity fuel cell.

Other Posts

EV Cooling Systems

The large batteries that EVs carry need to be maintained within a specific temperature range for optimal performance.

Diesel Turbocharging Basics

There’s a reason diesels typically utilize compound turbo setups instead of twin turbochargers.

Honda’s Cumulative EV Sales Tick Past the 1 Million Mark

The automaker says it has a vision to make battery-electric and fuel-cell electric vehicles represent 100% of its new vehicle sales by 2040.

Valvoline Global to Debut Ad During Super Bowl Pre-Game

The company will showcase its Restore & Protect motor oil in a 30-second ad before Super Bowl LVIII.