Pending Codes

Pending codes appear when a problem is detected in a monitored system. The Malfunction Indicator Light (MIL) is illuminated when a problem is detected during 2 consecutive drive cycles. A drive cycle is when the engine is started and turning off. A pending code is stored in Powertrain Control Module (PCM) during the first drive cycle when a failed system is detected. If the system does not fail during the second drive cycle, PCM concludes that the system has returned to normal or problem was mistakenly detected, and deletes pending code. If system failure is detected during a second drive cycle, PCM concludes that suspect system has failed, deletes pending code, illuminates MIL and stores Diagnostic Trouble Codes (DTC). If during 3 drive cycles after MIL was illuminated, system failure is not detected, PCM will turn off MIL but DTC will be stored in memory.