Pending code
Definition
A pending code is a fault the ECU detected once but has not yet confirmed; it is stored in Mode 07 memory and does not light the MIL. For two-trip codes the monitor must fail on a second consecutive drive cycle before the code becomes a stored (confirmed) code and the lamp comes on; if the second test passes, the pending code is dropped. Pending codes are valuable because they show faults that are developing or borderline, such as a lambda sensor getting slow, a catalyst just under threshold or an occasional misfire, and they appear immediately after a repair if the fix did not work. Most generic scan tools show them in a separate list; always read them after clearing codes and a short test drive to verify a repair. Any P-code can appear as pending; P0420, P0171, P030x and EVAP leak codes P0442/P0456 are the most common ones seen there.