14 - 64 FUEL SYSTEMS

Engine Timing - The engine controller cannot detect an incorrectly indexed timing chain, camshaft sprocket and crankshaft sprocket. The engine controller also cannot detect an incorrectly indexed distributor. However, these could result in a rich or lean condition causing an oxygen sensor fault to be stored in the engine controller.

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

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

Fuel Injector Malfunctions - The engine controller cannot determine if the fuel injector is clogged, the pintle is sticking or the wrong injector is installed. However, these could result in a rich or lean condition causing an oxygen sensor fault to be stored in the engine controller.

Excessive Oil Consumption - Although the engine controller monitors exhaust stream oxygen content when the system is in closed loop, it cannot determine excessive oil consumption.

Throttle Body Air Flow - The engine controller cannot detect a clogged or restricted air cleaner inlet or filter element.

Evaporative System - The engine controller will not detect a restricted, plugged or loaded evaporative purge canister.

Vacuum Assist - Leaks or restrictions in the vacuum circuits of vacuum assisted engine control sys-

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tem devices are not monitored by the engine controller. However, these could result in a MAP sensor fault being stored in the engine controller.

Engine Controller System Ground - The engine controller cannot determine a poor system ground. However, a fault code may be generated as a result of this condition.

Engine Controller Connector Engagement - The engine controller cannot determine spread or damaged connector pins. However, a fault code may be generated as a result of this condition.

HIGH AND LOW LIMITS

The engine controller compares input signal voltages from each input device with established high and low limits. If the input voltage is not within the limits and other fault code criteria are met, a fault code will be stored in memory. Other fault code criteria might include engine RPM limits or input voltages from other sensors or switches that must be present before a fault condition can be verified.

FAULT CODE DESCRIPTION

When a fault code appears, it indicates that the Engine Controller has recognized an abnormal condition in the system. Fault codes can be obtained from the Check Engine lamp on the Instrument Panel or from the Diagnostic Readout Box II (DRBII). Fault codes indicate the results of a failure but do not identify the failed component directly.