Powertrain, generic (extended)

P2A96 Alternative Fuel Tank Select Valve B Control Circuit Performance

Check engine lightOn

EmissionsRelevant

Drive cycleRequired

Limp modePossible

P2A96 is about tank select valve B working electrically but not doing what it is told. In an LNG layout like the one in Westport's US8726785B2, where one pump draws from either of two vessels through an insulated select valve, the module can verify the switch from the pump's behaviour: right after selecting a full vessel, the drive work per stroke should be normal, whereas a reading that stays low suggests the pump still sits on the empty side. The same patent warns that low work can also come from a mechanical defect, so a plausible check compares readings before and after the command. Cold-stiffened seals, ice and debris can hold the valve back. No manufacturer publishes P2A96 or its test window.

Likely causes

Valve B held by ice or cold-hardened seals

Debris preventing valve B from shifting fully

Pump defect interpreted as a select valve problem

Symptoms

Malfunction lamp on
Gas supply drops right after a tank change
One vessel stays full while the other runs dry

Repair estimate

DifficultyShop_onlyWorkshop job

Parts and labour€200–1,800

Time1.5–5 h

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

Parts involved

alt fuel tank select valve bwiring harnessafcm

Related codes

P2A95 P2A97 P2A98 P2A92 P2A9A P2A42

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