Generally speaking, you are not required to turn over your cell phone records to your insurance company or the other driver's insurance company unless a lawsuit has been filed in connection with the crash.
If you or another party has filed a lawsuit as a result of a motor vehicle accident, then you may be required to turn over your cell phone records at some point as part of the pre-trial discovery process.
As soon as a lawsuit has been filed in court, all parties involved will have an opportunity to collect and present evidence to support their side of the case. Civil discovery can involve any material(s) which may be reasonably expected to lead to admissible evidence in a lawsuit. In some instances the opposing side may argue that your cell phone records are admissible evidence to support their case, and you may be ordered to turn over your cell phone records.
If a lawsuit has not yet been filed, then you are not required to turn over your cell phone records. Insurance adjusters may try to convince you that they need your records before the claim can be processed, but it is important to avoid giving them sensitive information that they may attempt to use against you.
Ultimately, it may be in your best interests to consult with an experienced personal injury lawyer about your unique case. The more complex a personal injury case becomes, the more likely that a qualified attorney will be able to add value to the case.