Without Scan Tool

If a problem is sensed by the logic module or SMEC, often enough to be considered a malfunction, a fault code is stored in the module memory. If the problem is repaired, or ceases to occur, the module will cancel the fault code after 20-40 vehicle key On/Off cycles on 1986-87 models or 50-100 vehicle key On/Off cycles on 1988-89 models. The memory can also be cleared by disconnecting the battery (+) terminal (using the quick disconnect), however this may temporarily affect driveability until the logic module re-calibrates its adaptive memory. Fault codes that remain in the module memory can be called up and displayed either by using diagnostic tool C-4805 or by observing flashes or the power loss lamp.