DC21 - Check For Other Diagnostic Trouble Codes

- Was Diagnostic Trouble Code (DTC) 411 or 412 present with the DTC 159/129?

Yes -- For DTC 411, go to KE15. KE15 - Engine RPM Error During Self-Test

For DTC 412, go to KE1. KE1 - Check For RPM Drop

No -- Replace Powertrain Control Module (PCM), remove breakout box, rerun quick test. Quick Test Appendix (Detailed Testing Instructions)