Reasons for low idle speed on automatic transmission:
* Throttle Position Sensor (TPS) problems: The TPS sends throttle position information to the ECU. Low TPS voltage can cause low idle speed.
* Problems with the Mass Air Flow (MAF) sensor: The MAF measures the amount of air entering the engine. Incorrect MAF readings can result in improper fuel injection and poor idle speed.
* Idle Air Controller (IAC) contamination: The IAC regulates the air flow supplied to maintain idle speed. Contamination can cause it to malfunction and reduce idle speed.
* Air Intake System Problems: Air leaks or leaks in the air intake system can result in less air entering the engine, resulting in lower idle speed.
* Faulty Engine Control Module (ECU): The ECU controls engine operation, including idle speed. A faulty ECU can result in improper idle speed control.
*Throttle Body Problems: The throttle body itself may have mechanical problems, such as sticking or sticking, causing low idle speed.
* Transmission fault: Automatic transmission problems, such as low oil pressure or a faulty shift solenoid, can cause the idle speed to drop in neutral or when shifting.
Remedy:
* Check and clean TPS, MAF and IAC.
* Check for leaks or air leaks in the intake system.
* Scan the vehicle for trouble codes that may indicate a faulty ECU.
* Check the throttle valve and replace it if necessary.
*Seek professional diagnostics and repairs to resolve automatic transmission problems.