Non-Monitored Circuits

The Powertrain Control Module (PCM) does not monitor the following circuits, systems, and conditions even though they could have malfunctions that result in driveability problems. A trouble code may not be displayed for the following conditions.

Fuel Pressure - The PCM cannot detect a clogged [1][2]fuel pump inlet filter, clogged in-line fuel filter, a pinched fuel supply or return line, or air in the fuel system.

Fuel Injectors - The PCM cannot detect if the fuel injector is clogged, restricted, or damaged.

Fuel Requirements - Poor quality fuel can cause problems such as hard starting, rough idle, and stumble.

PCM Grounds - The PCM cannot detect a poor system ground. However, a trouble code may be stored in memory as a result of this condition.

Air Flow - The PCM cannot detect a clogged or restricted air cleaner inlet or filter element.

Exhaust System - The PCM cannot detect a plugged, restricted, or leaking exhaust system.

Cylinder Compression - The PCM cannot detect uneven, low, or high engine cylinder compression.

Excessive Oil Consumption - The PCM cannot determine excessive oil consumption.