Diagnostic Aids

DTC P0601 will set if, at ECM power up, checksum error exists. DTC P0604 will set if, at ECM power up, RAM error exists. Monitor runs once per drive cycle. Two trip fault.

Check for:

• Open ECM B+ fuse (10-amp) in passenger compartment fuse box.
• Open BTN fuse (30-amp) in engine compartment fuse/relay box.
• ECM malfunction.