Maryland Code, Commercial Law § 14-405

(a) The duties prescribed in § 14-404 of this subtitle may not be imposed on a guarantor if the guarantor shows that while the consumer product was in the possession of any person other than the guarantor, damage or unreasonable use, including failure to provide any reasonable and necessary maintenance disclosed under § 14-403 of this subtitle, caused the product to malfunction.

(b) The duties prescribed in § 14-404 of this subtitle may not be imposed on a provider if the provider shows that while the product was in the possession of any person other than the provider, damage or unreasonable use, including failure to provide any reasonable and necessary maintenance disclosed under § 14-403 of this subtitle, caused the product to malfunction or caused the inability of the provider to provide any service under the service contract.