Circuit/System Verification
WARNING: This page is about a different car, the 2018 GMC Yukon XL, 2018 GMC Yukon, 2018 Chevrolet Tahoe, 2018 Chevrolet Suburban 3500 HD, and 2018 Chevrolet Suburban. However, it is still accessible from the selected car via links, so may be relevant.
- Ignition ON.
- Verify the scan tool ISS/OSS Supply Voltage parameter displays OK.
- If OK is not displayed
Refer to Circuit/System Testing.
- Go to next step: If OK is displayed
- If OK is not displayed
- Engine idling in park position.
- Verify the scan tool Transmission ISS parameter varies with engine RPM and does not drop out.
- If the Transmission ISS does not vary with engine speed or drops out
Refer to Circuit/System Testing.
- Go to next step: If the Transmission ISS does vary with engine speed and does not drop out
- If the Transmission ISS does not vary with engine speed or drops out
- Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observe from the Freeze Frame/Failure Records data.
- Verify the DTC does not set.
- If the DTC sets
Refer to Circuit/System Testing.
- Go to next step: If the DTC does not set
- If the DTC sets
- All OK.