What Does P0619 Mean?
The Alternative Fuel Control Module has a RAM (Random Access Memory) or ROM (Read-Only Memory) error, indicating an internal hardware failure within the module's memory chips. This is more serious than a KAM error because it affects the module's ability to run its operating program. The driver may experience inability to run on alternative fuel, rough running, stalling, or a no-start condition on the alternative fuel system.
Common Causes
45%
Internal failure of the alternative fuel control module RAM/ROM chips
20%
Voltage spikes or electrical surges damaging module memory
15%
Corrupted module software requiring reflash
12%
Poor ground connections causing erratic module operation
8%
Water intrusion or physical damage to the control module
Diagnostic Steps
1
Verify charging system output is between 13.5–14.7V at idle and does not spike above 16V under load. Excessive voltage can damage module memory.
2
Inspect the alternative fuel control module for physical damage, water intrusion, or corrosion. Check the housing seal and connector weatherpack.
3
Attempt a module reflash with the latest manufacturer calibration file. Clear codes and drive the vehicle through a complete drive cycle to see if the code returns.
4
Check all power and ground circuits to the alternative fuel module using a DVOM — verify voltage within 0.1V of battery voltage on power pins and less than 0.1V drop on ground circuits.
5
If the code persists after reflash and all wiring checks pass, replace the alternative fuel control module and program with the correct calibration.
Estimated Repair Cost
$300 - $1,200
Parts + labor, varies by vehicle and location
The Alternative Fuel Control Module has a RAM (Random Access Memory) or ROM (Read-Only Memory) error, indicating an internal hardware failure within the module's memory chips. This is more serious than a KAM error because it affects the module's ability to run its operating program. The driver may e...
The most common cause of P0619 (Alternative Fuel Control Module RAM/ROM Error) is: Internal failure of the alternative fuel control module RAM/ROM chips
Typical repair costs for P0619 range from $300 to $1,200, depending on the vehicle, location, and whether you do it yourself or go to a shop.
The vehicle should still operate on conventional fuel, but alternative fuel operation may be disabled or severely compromised. Safe to drive to a repair facility on gasoline, but do not rely on alternative fuel operation until the issue is resolved.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P0619 to identify the root cause.
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Quick Info
Category
Powertrain
System
Alternative Fuel System
Difficulty
Type
Generic (SAE)
Recommended Tools
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