Toyota 4Runner intermittent stalling issue on hot days with no error codes on Toyota 4Runner

Some Toyota 4Runner owners report experiencing intermittent stalling issues on hot days without any error codes, which may be linked to several factors. These owners suggest that a malfunctioning Ignition Control Module (ICM) could lead to engine sputtering or stalling, particularly when idling. Additionally, faulty Engine Control Module (ECM) signals may contribute to erratic shifting and other electrical problems, including the intermittent stalling. The lack of error codes complicates diagnosis, as replicating the issue often requires specific conditions, such as hot weather driving. Some owners believe that erratic combustion processes due to ineffective spark timing control by the ICM can result in poor engine performance and occasional stalling. Utilizing an OBD-II scanner to check for any diagnostic trouble codes (DTCs) from the Engine Control Unit (ECU) can provide valuable insights into potential powertrain issues. Therefore, it is crucial for owners to consider these factors when diagnosing stalling problems.