P2A92 Alternative Fuel Tank Select Valve A Control Performance

P2A92 is the functional check for tank select valve A: the wiring tests pass, yet the fuel system does not behave as if the commanded vessel were connected. Software can judge this only through pressures. A patent by Cespira, the Westport and Volvo venture, outlines the logic for two compressed-gas supplies with their own pressure sensors: a supply-select valve assembly routes one supply to a compressor and the other to the regulator, and stages change whenever a supply falls under a set pressure. After such a command the newly chosen supply should start to lose pressure while the other holds steady. If nothing changes, or the wrong tank empties, valve A is probably sticking or leaking across its seat. No manufacturer publishes P2A92 or a threshold for it.

Likely causes

Symptoms

• Malfunction lamp on
• Tanks empty unevenly or in the wrong order
• Short gas supply although one vessel still holds fuel

Repair estimate

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

Parts involved

Related codes

References: law.cornell.edu, patents.google.com, patents.google.com.