This court is once again called upon to address the sanctions to be imposed on a party who fails to timely supplement responses to discovery requests. Anita Clark and Linda Ramirez (collectively referred to as “Clark”) are the survivors of Eulalia P. Mayorga and Emma Aurora Salazar Trejo, respectively, who were killed in a bus accident in Mexico. Clark brought this wrongful death and survival action against Trans-portes Del Norte (“TDN”) and Trailways, Inc. and eventually received judgment at the trial court level. Upon finding that the trial court abused its discretion in permitting Clark’s liability witness to testify, the court of appeals reversed the judgment of the trial court and remanded for a new trial. 756 S.W.2d 786 (Tex.App. — Corpus Christi 1988). We reverse the judgment of the court of appeals and remand the cause to that court for further proceedings.
In October 1979 Mayorga and Trejo purchased round trip tickets to Mexico City from a Trailways bus station in Corpus Christi, Texas. The decedents departed Corpus Christi in a Trailways bus, but were later transferred to a TDN bus at Brownsville, Texas, for the remainder of the trip. Prior to reaching their destination, Mayor-ga and Trejo were killed when the TDN bus veered off a roadway in Mexico and overturned. The jury found that TDN, through the driver of its bus, was negligent in maintaining a proper lookout and rate of speed. Based on these jury findings, the trial court rendered judgment against TDN and Trailways.
The primary dispute on appeal arises from Clark’s failure to supplement a pretrial discovery request made by TDN. In 1981 TDN served Clark with interrogatories that included a request for the names and addresses of any persons who investigated the accident, as well as the details of any oral reports received from such persons. Clark initially responded that the identities and other requested information about such persons were unknown. However, Clark supplemented this response on August 27,1986, by directly referencing an exhibit to the deposition of a TDN employee, which had previously been filed with the court. The relevant document in this exhibit had originally been produced by TDN. After receiving the supplemental response, TDN filed a motion for sanctions and requested the trial court not to permit the testimony of any liability witness whose name and address should have been revealed in Clark’s answers to the interrogatories. The trial court overruled the motion at a pretrial hearing and began trial on September 2, 1986.
TDN contends that the trial court abused its discretion by allowing the testimony of Hector Lira Morales, who investigated the accident for the federal police in Mexico. At the time of the trial in 1986, the text of Tex.R.Civ.P. 215(5) (Vernon Supp.1987) read as follows:
5. Failure to make supplementation of discovery response in compliance with Rule 166b. A party who fails to supplement seasonably his response to a request for discovery in accordance with paragraph 5 of Rule 166b shall not be entitled to present evidence which the party was under a duly to provide in a supplemental response or to offer the testimony of an expert witness or of any other person having knowledge of discoverable matter when the information re*646quired by Rule 166b concerning the witness has not been disclosed, unless the trial court finds that good cause sufficient to require admission exists.1
The record does not indicate that Clark supplied TDN with Lira’s address as requested in its interrogatories. Thus, the trial court should not have allowed Lira’s testimony absent a finding of good cause to require its admission. Morrow v. H.E.B., Inc., 714 S.W.2d 297, 297-98 (Tex.1986) (per curiam).
The good cause exception to rule 215(5) must be viewed in perspective with the underlying principles of the discovery process. By excluding the testimony of witnesses whose identities or locations are not revealed in response to discovery requests, rule 215(5) promotes full discovery and deters litigants from violating discovery rules. However, this sanction was neither designed nor intended to punish a litigant who cannot, in the exercise of good faith and due diligence, respond to a discovery request in a timely manner. The good cause exception thus provides trial courts with the latitude to permit testimony in those situations and excuse the party’s failure to timely supplement the discovery request. Nevertheless, parties should not be permitted to rely on the good cause exception as a means to evade their duty to engage in full discovery. Thus, a showing of good cause pursuant to rule 215(5) must encompass a showing of good cause for the offering party’s failure to respond to proper discovery requests. See Galvin v. Gulf Oil Corp., 759 S.W.2d 167, 171-72 (Tex.App.—Dallas 1988, writ denied).
Upon overruling TDN’s motion for sanctions, the trial court stated that “if [Lira] was the original DPS [sic] officer, the investigator of this particular accident, I think that he sure would be a witness in this particular proceedings.” This statement suggests that the trial court predicated its implicit finding of good cause on the fact that Lira, as the original investigating officer at the accident, possessed peculiar knowledge of the underlying facts of the accident. However, this fact cannot constitute good cause sufficient to require the testimony of Lira. A contrary rule would permit a party opposing discovery to deliberately withhold the name and other discoverable information concerning a key liability witness, and then emphasize the peculiar knowledge held by that witness as being a factor of good cause to excuse the party’s failure to disclose. Such a result would only frustrate the underlying purpose of rules regarding discovery, which were designed to prevent “trial by ambush” and to ensure fairness. Gutierrez v. Dallas Indep. School Dist. 729 S.W.2d 691, 693 (Tex.1987).
As the party offering the testimony of Lira, Clark bore the burden to show good cause to the trial court. Yeldell v. Holiday Hills Retirement & Nursing Center, Inc., 701 S.W.2d 243, 246-47 (Tex.1985). Clark did not make any such showing at the pretrial hearing on TDN’s motion for sanctions. Despite this failure to show good cause at the hearing, Clark points out that the deposition of Lira had been filed with the trial court at the time of the hearing. For this reason, Clark contends that the trial court was permitted to consider the deposition testimony of Lira in determining the existence of good cause. Furthermore, Clark relies upon Downer v. Aquamarine Operators, Inc., 701 S.W.2d 238, 241 (Tex.1985), cert. denied, 476 U.S. 1159, 106 S.Ct. 2279, 90 L.Ed.2d 721 (1986), for the proposition that the trial testimony of Lira provides an additional basis for affirming the good cause finding. According to Clark, the trial court retained plenary jurisdiction to review its pretrial order on TDN’s motion for new trial; thus, in reconsidering its order allowing Lira’s testimony, the trial court was permitted to review all evidence that had been subsequently placed in the record, including Lira’s testimony at trial. See Downer, 701 S.W.2d at 241.
*647Nevertheless, Lira’s testimony at deposition and trial does not provide any facts to support the trial court’s finding of good cause. According to his deposition testimony, Lira was not contacted about becoming a witness in the case until approximately ten days prior to the eventual date of trial. Lira also denied having given any reports regarding the accident up to that date, apart from his original investigation report prepared immediately following the accident. At trial, Lira further claimed to have moved frequently to various locations in Mexico following the accident.
These facts, however, do not permit a reasonable inference that Clark was unable to comply with the discovery request by TDN or seasonably supplement its answers to those requests. Lira’s testimony falls short of indicating Clark’s good faith efforts to locate Lira or her inability to anticipate the use of his testimony at trial, which could otherwise support a finding of good cause to permit the testimony of an unidentified witness. See, e.g., Johnson v. Gulf Coast Contracting Servs., Inc., 746 S.W.2d 327, 329 (Tex.App.—Beaumont 1988, writ denied); Ellsworth v. Bishop Jewelry & Loan Co., 742 S.W.2d 533, 534 (Tex.App.—Dallas 1987, writ denied). The trial court thus abused its discretion in finding good cause to allow the testimony of Lira.
We do not reach the issue of whether the admission of Lira’s testimony constitutes reversible error, because TDN and Trailways failed to properly preserve their complaint as to the admission of his testimony. Generally, parties must present a timely objection, motion, or request to the trial court in order to preserve a complaint for appellate review. Tex.R.App.P. 52(a). By failing to object when an undisclosed witness is offered at trial, a party waives any complaint under rule 215(5) as to the admission of testimony from that witness. Security Ins. Co. v. Nasser, 755 S.W.2d 186, 194 (Tex.App.—Houston [14th Dist.] 1988, no writ); Greenstein, Logan & Co. v. Burgess Mktg., Inc., 744 S.W.2d 170, 178 (Tex.App.—Waco 1987, writ denied).
Neither TDN nor Trailways raised an objection under rule 215(5) when Lira testified at trial. Nevertheless, they contend that TDN’s pretrial motion for sanctions properly preserved their complaint as to the admission of Lira’s testimony. We disagree. The rules requiring timely objections or motions are designed to allow trial courts to correct any errors made during the course of the proceedings. E.g., Lewis v. Texas Employers’ Ins. Ass’n, 151 Tex. 95, 99, 246 S.W.2d 599, 601 (1952). By failing to object when an undisclosed witness or evidence is offered at trial, parties such as TDN and Trailways effectively deny a trial court the opportunity to review and correct a prior finding of good cause. Parties in any instance should not assume that the trial court is incapable of recognizing an error in a previous finding of good cause.
Moreover, an erroneous finding of good cause under rule 215(5) does not provide a basis for reversal on appeal unless the undisclosed witness or evidence is actually offered and admitted at trial. An objection or motion at that point in the proceedings provides the trial court with a final opportunity to prevent the erroneous admission of the testimony or evidence, thereby avoiding the possibility of a complete new trial to correct any reversible error resulting from its admission. The efficient administration of justice thus requires that trial courts have the opportunity to review any previous finding of good cause, regardless of whether the finding occurred several months or one day prior to the actual offering of the testimony or evidence at issue.
For these reasons, we believe that the better-reasoned approach is to require a party opposing the admission of testimony or evidence under rule 215(5) to object when the testimony or evidence is offered at trial.2 This rule serves the dual purpose *648of ensuring trial courts the opportunity to review any previous finding of good cause, while providing litigants and courts alike with a uniform and consistent rule regarding the preservation of error under rule 215(5). By failing to object when Clark offered Lira’s testimony at trial, TDN and Trailways waived their complaint as to the admission of his testimony.3
In holding that the trial court committed reversible error by allowing the testimony of Lira, the court of appeals did not reach the other points of error raised by TDN and Trailways on appeal. We thus remand this cause to the court of appeals to address the remaining points of error. McConnell Constr. Co. v. Insurance Co. of St. Louis, 428 S.W.2d 659, 661 (Tex.1968).
We reverse the judgment of the court of appeals and remand the cause to that court for further proceedings.
GONZALEZ, J., dissents.. This rule was amended effective January 1, 1988, to place the burden of establishing good cause on the party offering the evidence and to require good cause to be shown in the record. Tex.R.Civ.P. 215(5).
. In finding that TDN and Trailways properly preserved error, the dissent places great reliance on the fact that the trial court ruled on the pretrial motion for sanctions on the day preceding Lira’s testimony at trial. The dissent unfortunately fails to provide practitioners and appellate courts with a workable rule regarding the preservation of error under rule 215(5). Liti*648gants in Texas courts should instead be provided with uniform and consistent rules regarding the proper preservation of error.
The dissent's reliance on Tex.R.App.P. 52(b) is misplaced. When a court hears objections to offered evidence outside the presence of the jury and admits the evidence, rule 52(b) relieves a party from having to reurge its objection before the jury. A pretrial objection occurs prior to the actual offering of the testimony and is thus not addressed by rule 52(b). Under the dissent’s reading of the rule, however, a party could theoretically preserve error by merely raising an objection at any point prior to trial.
. This court in Gee v. Liberty Mut. Fire Ins. Co., 765 S.W.2d 394, 396 (Tex.1989), suggested in dicta that the overruling of a pretrial motion to exclude undisclosed witnesses under rule 215(5) would be sufficient to preserve error. In Gee, we did not directly address the issue presented in this case, Le., the proper time for objecting under rule 215(5), since neither party contested the court of appeals' holding that error had not been preserved with respect to two undisclosed witnesses. Gee, 765 S.W.2d at 396. Thus, the dicta in Gee is not controlling on this issue.