Diagnostic techniques for Automatic Transmissions issues

A transmission that is automatic transmission is an amazing piece of electromechanical engineering. It is comprised of more than 800 parts functioning in harmony. When that harmony is interrupted by a sudden shift or an odd whine, the complex nature of the system can seem overwhelming.

If you're a DIYer or just a curious auto owner, knowing how mechanics "talk" about your car's engine could help you avoid a huge repair cost. This article will provide a detailed explanation of the primary diagnostic techniques that are used to identify issues with your transmission.

1. The "First Responders": Fluid & Visual Checks

Before attempting to use high-tech equipment, the professionals must first master the fundamentals. The transmission fluid acts as the vital component of the system. It supplies hydraulic pressure, cooling, and the ability to lubricate.

• Fluid Level: Examine the dipstick as the engine is running warm and idle. Low levels can cause delays or slipping.

• Fluid Condition: * Bright Red: Healthy.

  • Dark Brown/Black. It indicates overheating or aging fluid.

  • Burnt Smell: An indication that internal bands or clutches are shifting and are overheating.

  • Metal Specks Internal wear isa very serious happening.

• "The 'Newspaper Test": Placing a clean piece of paper under the vehicle overnight could aid in determining the area and color of leaks (Transmission fluids are usually red).

2. Digital Diagnostics: The OBD-II Scan

Today, modern transmissions can be controlled via the transmission control module (TCM). If something goes wrong, the TCM will throw a "P-code." Utilizing the OBD II scanner, it is possible to read these codes to determine the location of the failure.

3. Mechanical Stress Tests

In the event that fluid pressure is clean and the computer remains silent Technicians make use of an "active test" to determine how the computer handles pressure.

• The Stall Test: This involves holding the brake while pressing the accelerator for a short period of time to determine the engine's maximum RPM (stall speed). A low stall rate suggests problems with the engine, whereas a high stall rate often indicates a problem with the torque converter.

• Time-lag test: This measures the duration it takes for the transmission to start working in the transition from Neutral, Drive, and Reverse. A delay that is more than 1.5 seconds typically is a sign of an issue with the pressure in the hydraulic system or worn seals.

4. Advanced Pressure Testing

To take a deep dive, the pressure gauge of a hydraulic system is affixed to certain "taps" in the case of transmission. This will tell you whether it is the case that tension in the line is at the right levels to activate the clutches and open valves. When the line pressure appears not to be high, it is most likely a failed pump, a blocked filter, or an inoperable valve for regulating pressure.

When to Seek Professional Help

While the most basic checks can be done by yourself, internal diagnostics typically require the use of specialized equipment. Consult a specialist if you observe:

1. Limp Mode Car stays on a single setting (usually the 3rd) to safeguard itself.

2. Extreme shaking: The vibration or the grinding of metal during shifts.

3. The metal inside the Pan: If you spill the transmission pan and discover "glitter" (metal shavings), then an internal repair is probably required.