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STATE DISPLAY TEST MODE

The switch inputs used by the engine controller have only two recognized states, HIGH and LOW. For this reason, the engine controller cannot recognize the difference between a selected switch position versus an open circuit, a short circuit, or a defective switch. If the change is displayed, it can be assumed that the entire switch circuit to the engine controller is functional. From the state display screen access either State Display Inputs and Outputs or State Display Sensors.

STATE DISPLAY INPUTS AND OUTPUTS

Connect the DRB II tester to the vehicle. Access the State Display screen. Then access Inputs and Outputs. The following is a list of the engine control system functions accessible through the Inputs and Outputs screen.

Park/Neutral Switch

Speed Control Resume Brake Switch

Speed Control On/Off Speed Control Set A/C Switch Sense

Z2 Voltage Sense

S/C Vent Solenoid S/C Vacuum Solenoid A/C Clutch Relay EGR Solenoid

Auto Shutdown Relay

Radiator Fan Relay Purge Solenoid PTU Solenoid Check Engine Lamp

STATE DISPLAY SENSORS

Connect the DRB II tester to the vehicle and access the State Display screen. Then access Sensor Display. The following is a list of the engine control system functions accessible through the Sensor Display screen.

Battery Temp Sensor

Oxygen Sensor Signal

Coolant Temperature

Coolant Temp Sensor Throttle Position Minimum Throttle Battery Voltage MAP Sensor Reading AIS Motor Position Adaptive Fuel Factor Barometric Pressure

Min Airflow Idle Speed Engine Speed

Fault #1 Key-On Info

Module Spark Advance

Speed Control Target

Fault #2 Key-on Info

FUEL SYSTEMS 14 - 125

Fault #3 Key-on Info

Speed Control Status

Speed Control Switch Voltage

Charging System Goal

Theft Alarm Status

Map Sensor Voltage

Vehicle Speed

Oxygen Sensor State

MAP Gauge Reading

Throttle Opening

Total Spark Advance

CIRCUIT ACTUATION TEST MODE

The circuit actuation test mode checks for proper operation of output circuits or devices which the engine controller cannot internally recognize. The engine controller can attempt to activate these outputs and allow an observer to verify proper operation. Most of the tests provide an audible or visual indication of device operation (click of relay contacts, spray fuel, etc.). Except for intermittent conditions, if a device functions properly during testing, assume the device, its associated wiring, and driver circuit working correctly.

OBTAINING CIRCUIT ACTUATION TEST

Connect the DRB II tester to the vehicle and access the Actuators screen. The following is a list of the engine control system functions accessible through Actuators screens.

Stop All Tests

Ignition Coil #1

Fuel Injector #1

Fuel Injector #2

Fuel Injector #3

Fuel Injector #4

Fuel Injector #5

Fuel Injector #6

AIS Motor Open/Close Radiator Fan Relay A/C Clutch Relay Auto Shutdown Relay Fuel Pump Relay Purge Solenoid

S/C Serv Solenoids Alternator Field All Solenoids/Relays

ASD Fuel System Test

THROTTLE BODY MINIMUM AIR FLOW CHECK PROCEDURE

(1)Warm engine in Park or Neutral until the cooling fan has cycled on and off at least once.

(2)Ensure that all accessories are off.

(3)Hook-up the timing check device and tachom-

eter.

Fig. 23 3.0L PCV Valve

(8) Disconnect the idle purge hose from the engine vacuum harness tee (Fig. 24).

Fig. 24 3.0L Idle Purge Hose

(9)Install Air Metering Fitting #6457 (0.125 inch orifice) in the intake manifold mounted idle purge hose (Fig. 25).

(10)Connect Diagnostic Readout Box II (DRB II).

(11)Restart the engine, allow engine to idle for at least one minute.

(12)Using the DRBII, access Min. Airflow Idle

Speed.

(13)The following will then occur:

²AIS motor will fully close.

²Idle spark advance will become fixed.

²Engine RPM will be displayed on Diagnostic Readout Box II (DRB II)

Fig. 25 Air Metering Fitting, Special Tool 6457

(14) Check idle RPM with tachometer, if idle RPM is within the below specification then the throttle body min. air flow is set correctly.

IDLE SPECIFICATIONS

(15) If idle RPM is not within specifications, shut off the engine and clean the throttle body as follows:

(a) Remove the throttle body from engine.

WARNING: CLEAN THROTTLE BODY IN A WELL VENTILATED AREA. WEAR RUBBER OF BUTYL GLOVES, DO NOT LET MOPAR PARTS CLEANER COME IN CONTACT WITH EYES OR SKIN. AVOID INGESTING THE CLEANER. WASH THOROUGHLY AFTER USING CLEANER.

(b)While holding the throttle open, spray the entire throttle body bore and the manifold side of the throttle plate with Mopar Parts Cleaner. Only use Mopar Parts Cleaner to clean the throttle body.

(c)Using a soft scuff pad, clean the top and bottom of throttle body bore and the edges and manifold side of the throttle blade. The edges of the throttle blade and portions of the throttle bore that are closest to the throttle blade when is closed, must be free of deposits.

(d)Use compressed air to dry the throttle body.

(e)Inspect throttle body for foreign material.

(f)Install throttle body on manifold.

(g)Repeat steps 1 through 14. If the minimum air flow is still not within specifications, the problem is not caused by the throttle body.

(16)Shut off engine.

(17)Remove Air Metering Fitting #6457 from the intake manifold idle purge hose. Reconnect the hose to the engine vacuum harness tee.

(18)Remove the plug from the PCV valve. Reconnect the PCV valve hose to the PCV valve.

(19)Disconnect the DRB II.

IGNITION TIMING PROCEDURE

Refer to Group 8D Ignition System.

60-WAY ENGINE CONTROLLER WIRING CONNECTOR

Refer to the engine controller wiring connector description (Fig. 26) for information regarding wire colors and cavity numbers.