Powertrain, generic · Computer and auxiliary outputs

P0619 Alternative Fuel Control Module RAM/ROM Error

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

CARB treats gas-fuelled vehicles (CNG, LPG, also the gas mode of bi-fuel cars) like petrol cars up to model year 2018 and under an approved manufacturer plan afterwards. P0619 means the separate alternative fuel module reports an error in its working memory (RAM, read/write test) or program memory (ROM/flash, checksum) – one code for both, while the engine module uses P0604 and P0605. No manufacturer was found that uses the code; Roush's Ford propane systems report gas module failures as U0108 and the engine module's own memory errors as P0604/P0605. A module whose memory cannot be trusted will typically shut down gas operation: bi-fuel cars run on petrol, dedicated gas engines may not start. The usual remedies are reprogramming the gas module with a stable supply, then replacement.

Likely causes

Interrupted or faulty programming of the gas module
Voltage dips, supply, ground or corrosion
Internal hardware defect (memory chip)
Manufacturer software fault

Symptoms

  • Check engine or gas system warning light
  • No gas operation, switch to petrol
  • Starting problems on dedicated gas engines
  • Possibly communication code U0108

Repair estimate

DifficultyHardWorkshop job
Parts and labour€100–1,200
Time0.5–2.5 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

alternative fuel control modulemodule power supply

Related codes

P0618P0604P0605P0601U0108

References: law.cornell.edu, roushcleantech.com.