1998 Other Chevrolet Models P1631 theft system password inco

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Password learn procedure must be performed if Instrument Panel Cluster (IPC) is replaced. A password is communicated between IPC and Powertrain Control Module (PCM) to provide engine operation. If IPC is replaced, the PCM must learn the password from the IPC.
NOTE:If PCM is replaced, the Electronically Erasable Programmable Read Only Memory (EEPROM) should be programmed. When EEPROM is programmed, the PCM will learn the password when ignition is initially turned on. Password learn procedure is not required when replacing the PCM and EEPROM is programmed.

Attempt to start engine and then leave ignition on. DO NOT turn ignition off. The THEFT SYSTEM indicator light will flash for 10 minutes.
On Achieva, THEFT SYSTEM indicator light is located on IPC, just to the right of the coolant temperature gauge and may also be displayed as SECURITY indicator light. On Grand Am, THEFT SYSTEM indicator light is located on IPC, just to the right of the fuel gauge. On Skylark, THEFT SYSTEM indicator light is located on IPC, just above fuel gauge.
On all models, once THEFT SYSTEM indicator light stops flashing, attempt to start the engine. If engine starts, the password learn procedure is complete. If engine does not start, ensure procedure was properly followed. If procedure was properly followed, check for any DTCs.