System Diagnosis

Chrysler Corp. multi-point fuel injection system is equipped with "On-Board Diagnosis", which is self-diagnostic capability that checks several circuits. Self-diagnostic capabilities of system can simplify testing if properly utilized.

If abnormal signals occur often enough to indicate valid problem, logic module will store appropriate fault code for later display. If problem is either repaired or disappears by itself, logic module will remove fault code after 30 engine starts have occurred.

When fault code for coolant or charge temperature sensors, wastegate solenoid, MAP sensor, TPS, O2 sensor, O2 feedback system full rich or full lean, distributor sync pick-up, high battery voltage or loss of battery voltage is set, power loss lamp comes on. Power loss lamp, located on dashboard, informs operator that malfunction in system has occurred and that immediate service is required.

Lamp also indicates that logic module has entered "Limp-In Mode" to keep system operating. Logic module attempts to compensate for failure of any particular component by using input from remaining sensors. This capability may allow vehicle to reach repair facility under its own power.

If either power loss lamp comes on or certain driveability and engine performance problems exist, probable source of these difficulties may be determined by displaying and recording fault codes. Check FAULT CODES to determine questionable circuit.

Using CHRYSLER CORP. MULTI-POINT FUEL INJECTION SYSTEM WIRING DIAGRAM and COMPONENT CONNECTOR IDENTIFICATION CHARTS, locate test points for each circuit. Repair or replace components as necessary.