Conditions for Clearing the DTC

WARNING: This page is about a different car, the 2002 Buick Regal and 2002 Buick Century. However, it is still accessible from the selected car via links, so may be relevant.

The DTC becomes history when then conditions for setting the DTC are no longer present.
The history DTC clears after 40 malfunction free warm-up cycles.
The PCM receives the clear code command from the scan tool.

Fig 1: Identifying DTC P1189 Diagnostic Table

Courtesy of GENERAL MOTORS CORP.