DTC 17

DTC 17 High Resolution Circuit Fault:

High Resolution Circuit Fault:

Circuit Description
The optical sensor provides a high resolution signal to the Powertrain Control Module (PCM) by counting pulses on the sensor disk located in the injection pump. The high resolution is one of the most important inputs by the PCM for fuel control and timing.

DIAGNOSTIC TROUBLE CODE (DTC) 17 WILL SET WHEN
8 cam reference pulses without and increase in high resolution counts (internal to PCM).

ACTION TAKEN (PCM will default to)
Backup fuel.

DTC 17 WILL CLEAR WHEN
The fault condition(s) no longer exist, and the ignition switch is cycled "OFF" then "ON."

DTC CHART TEST DESCRIPTION
Number(s) below refer to circled number(s) on the diagnostic chart.
1. This step will determine if there is a 5 volt reference.
2. This step checks the ground circuit.
3. This step will check to see if the sensor is sending a signal back to the PCM.

DIAGNOSTIC AIDS
When PCM is in backup fuel. fast idle and poor performance problems will exist. If DTC 18 is also stored, there is a possible problem with CKTs 474 or 987. It is possible DTC 17 may set if there is air in the fuel system.