Energy Exascale Earth System Model (E3SM) v2 simulates a too weak Atlantic meridional overturning circulation (AMOC) compared to observations, which has been a persistent bias in the current and prior model versions. In this project, we investigate the cause of the weak AMOC bias in E3SM v2 and explore the impacts of this bias on the Atlantic climate mean state, variability, and change. Firstly, we have identified that the weak AMOC bias is accompanied by a too cold Indian Ocean, a too cold North Atlantic, a too warm South Atlantic, and a too fresh Atlantic relative to the global ocean. We argue that correcting the Indian Ocean temperature bias can help reduce the rest of these mean-state biases, including the weak AMOC bias, through inter-basin teleconnections. Second, we evaluate the E3SM v2 simulation of Atlantic climate variability and historical change and explore the role of the weak AMOC bias. The results concerning E3SM v2 are also compared against other climate models from the Coupled Model Intercomparison Project Phase 6 (CMIP6) from the perspective of model biases and AMOC simulations.