To communicate internal control weaknesses to external auditors, start with clear, organized documentation detailing each weakness, its impact, and any corrective actions taken. Be transparent, sticking to facts without minimizing or exaggerating issues. Emphasize corrective actions and any timelines for improvements to show a proactive stance.

Be proactive and transparent, prepare clear documentation, provide a root cause analysis, outline corrective action plan and the commitment of management, facilitate open dialogue, provide regular updates and emphasize a culture of compliance.

Communication with external auditors should be prompt, transparent and fact based. Specific of weakness in controls/ processes should be documented rather than a generic conclusion so that external auditors can also suggest remediation steps. Impact of weakness, mitigation action plan with timelines and leveraging alternative controls/ processess should be clearly communicated along with a message that core leadership is made aware of wekness and aligned to mitigate it soonest

Just be transparent with them, their recommendations might help your business given their experiences, exposure and expertise. After all its your responsibility to give them sufficient and appropriate information.