Test Description

Number(s) below refer to the step number(s) on the Diagnostic Table.

1. The On-Board Diagnostic (OBD II) System Check prompts the technician to complete some basic checks and store the Freeze Frame and Failure Records data on the scan tool if applicable. This creates an electronic copy of the data taken when the malfunction occurred. The information is then stored on the scan tool for later reference.
2. This step determines if DTC P0140 is the result of a hard failure or an intermittent condition.
3. Disconnecting the HO2S2 and jumpering the sensor signal circuit and the sensor low circuit to ground will determine if the ECM or wiring or HO2S2 is malfunctioning.
4. Determines which circuit the malfunction is in. If the sensor signal circuit and the sensor low circuit are OK, then the ECM connection or ECM is malfunctioning.
5. The replacement ECM must be reprogrammed. Refer to the latest Techline procedure for ECM reprogramming.