LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Jeep >> 1999 >> Cherokee Limited, 2.5 P >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Tests W/Codes >> Self-Diagnostic Tests >> DTC P0601: Internal Controller Failure
April 5, 2026: LEMON Manuals is launched! Read the announcement.

DTC P0601: Internal Controller Failure

NOTE: For connector terminal identification, see CONNECTOR IDENTIFICATION . For circuit identification and wiring diagram, see CHEROKEE wiring diagram in WIRING DIAGRAMS article.
NOTE: DTC P0601: INTERNAL CONTROLLER FAILURE is monitored with ignition on. DTC may be stored in Powertrain Control Module (PCM) if PCM senses internal checksum for software failed, does not match calculated value. Possible cause is: defective PCM.

Turn ignition on, with engine off. Using scan tool, read DTCs. If DTC P0601: INTERNAL CONTROLLER FAILURE is present, replace PCM. Perform TEST VER-2A. If DTC P0601: INTERNAL CONTROLLER FAILURE is not present, test is complete.