P0605 - Internal Control Module ROM Error
The P0605 code indicates that the Engine Control Module (ECM) has detected an internal fault in its Read Only Memory (ROM). This memory stores critical programming data for engine operation. A ROM error typically means the ECM's firmware is corrupted or the chip has failed, leading to incorrect calculations and potential drivability issues. This is a serious problem because the ECM cannot properly control engine functions.
1. Most Common Causes
- Faulty Engine Control Module (ECM)
- Corrupted ECM software/firmware
- Electrical issues like voltage spikes or poor ground connections
- Water damage or corrosion inside the ECM
2. Symptoms You Will Notice
- Check Engine Light illuminated
- Engine stalling or misfiring
- Poor acceleration or reduced power
- Engine may not start or run erratically
3. Step-by-Step Diagnosis
Step 1: Use an OBD2 scanner to confirm the code and check for other related codes.
Step 2: Inspect the ECM for visible damage, corrosion, or water intrusion.
Step 3: Check all wiring and connectors to the ECM for loose or corroded terminals.
Step 4: Perform a battery and charging system test to ensure stable voltage.
Step 5: If no external issues found, the ECM likely needs reprogramming or replacement.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
No, it is not safe. The ECM controls critical engine functions, and a ROM error can cause unpredictable behavior like stalling or loss of power, increasing the risk of an accident.
How much does it cost to fix?▼
Repair costs vary widely. ECM reprogramming may cost $100-$300, while replacement can range from $500 to $1500 including labor and programming.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.