DTC P1626: Invalid Fuel Enable Password: Description

WARNING: This page is about a different car, the 2002 GMC Savana, 2002 Chevrolet Chevy Express, 2001 GMC Savana, and 2001 Chevrolet Chevy Express. However, it is still accessible from the selected car via links, so may be relevant.

The Powertrain Control Module (PCM) communicates with other modules using class 2 serial data circuit. Passlock(tm) module sends a fuel continue password to PCM, via Class 2 Serial Data circuit, after system has sensed proper operation of ignition switch and lock, and determined that switch and lock have not been tampered with. If this password matches password stored in PCM, fuel will be enabled. If the Passlock(tm) module does not send a password, or if the PCM does not receive matching password, vehicle will not start, or it may start and stall. This will set DTC P1626 in PCM memory. If communication is lost after receiving password, Passlock(tm) system will go into fail enable, set DTC U1192 in control module, and engine will continue to run. This will allow engine to restart on future ignition cycles but may set a DTC P1626 as engine is started. If battery is disconnected or codes are cleared, vehicle will lose its fail enable status and will not start until communication is reestablished.

DTC P1626 will set if PCM has not established communications with Passlock(tm) module and has not received a valid password before fuel disable decision point was reached. PCM stores the DTC in history after the first failure but will not illuminate Malfunction Indicator Light (MIL). PCM records operating conditions at the time the diagnostic fails. PCM stores failure information in scan tools freeze frame/failure records. A history DTC will clear if no fault conditions have been detected for 40 warm-up cycles. A warm-up cycle occurs when coolant temperature has risen 40°F (22°C) from start-up coolant temperature and engine coolant temperature exceeds 160°F (70°C) during same ignition cycle. Use scan tool CLEAR INFORMATION FUNCTION.