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P1604 Diagnostic Trouble Code Discussion for May 2025

PCM Internal Dual-Port Ram Read/Write Integrity Failure


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Trouble Ticket Help Requests for DTC P1604
Help Request Posted
2017 Toyota 86 2.0L No Start, Poor Idle Quality
P1604: Running instability. Engine was replaced for a rod knock. Engine ran fine but knocked. Engine was removed disassembled crank turned new bearings new rings and then reassembled. Engine cranks normal and sounds normal cranking, however when it tries to start it runs for about 2 ...
May 04, 2025