Run a buzz test using a capable scan tool.
The P1316 does not mean that your IDM is bad, you just need to look into it a bit further. A buzz test will reveal a code that will help you pinpoint the location of the failure.
Typical causes of this code:
- Under Valve Cover Harness (UVCH)
- UVCH connector
- Valve Cover Gasket
- Injector (not likely)