Scan Tool Testing and Procedures

SCAN TOOL HOOK-UP

- Connect the scan tool to the diagnostic connector located in the engine compartment. The separate red clip is connected to the positive post of the battery.
- With the scan tool properly connected, all character positions on the display should briefly illuminate, and the copyright message should appear.
NOTE: At any time after the copyright screen, the user may press the F3 key for help.
- A commonly reported problem is that the scan tool screen is blank. If the screen is blank after the scanner is attached to the vehicle, do the following:
Make sure all cable connections are properly seated and fit snugly.
Make sure the cables are in good condition (no broken or shorted wires).
Make sure the cartridge is installed properly into the scan tool.
Try the scan tool on another vehicle. If the scan tool screen is still blank, have the unit repaired. If it now performs properly, continue with next step.

Data Link Connector Identification:

Make sure all cable connectors are in good condition (no flared or pushed out terminals). If the connector is good, continue with next step.

On-Board Diagnostic Connector Identification (Wire Color May Vary By Model):

Check the BK/WT wire in the diagnostic connector for continuity to ground.

ACCESSING AND DELETING FAULT CODES

CAUTION: Be sure to apply parking brake and/or block wheels before performing idle check or adjustment, or any engine running tests.

Single Board Engine Controller (SBEC):

1. Connect the scan tool to the diagnostic connector located in the engine compartment near the engine controller.
2. If possible, START the engine, turn ON the air conditioning, and shift the transmission selector through all of the gears, returning to PARK (A/T) or NEUTRAL (M/T). Turn OFF the air conditioning and shut OFF the engine.
3. Turn ON the ignition switch and observe the CHECK ENGINE LAMP. It should light for approx. 2 seconds then go out. Access "Read Fault Data" on the scan tool and record any fault codes received.
NOTE: Refer to FAULT CODE IDENTIFICATION AND DIAGNOSTIC CHART REFERRAL for a listing of fault codes and related diagnostic routines.
4. Access "Erase Fault Data" and erase the fault code memory.

STATE DISPLAY TEST MODE

Inputs and Outputs

The switch inputs read by the engine controller have two recognized states (high and low). Therefore, the engine controller cannot determine the difference between a switch position and an open or shorted circuit, or a defective switch. If the displayed state changes as the switch is toggled and the state corresponds to the operation of the switch, it can be assumed that the circuit is good.

Connect the scan tool to the vehicle and access the "State Display" screen. From the "State Display" screen, access the "State Display Inputs And Outputs" screen.

The following components can be monitored in this mode:

- Air conditioning clutch relay
- Air conditioning switch sense
- Auto shutdown relay
- B1 voltage sense
- Brake switch
- CHECK ENGINE LAMP
- EGR solenoid
- PARK/NEUTRAL switch
- PTU solenoid
- Purge solenoid
- Radiator fan relay
- Speed Control ON/OFF
- Speed control RESUME
- Speed control SET
- Speed control vacuum solenoid
- Speed control vent solenoid

Sensors

The switch inputs read by the engine controller have two recognized states (high and low). Therefore, the engine controller cannot determine the difference between a switch position and an open or shorted circuit, or a defective switch. If the displayed state changes as the switch is toggled and the state corresponds to the operation of the switch, it can be assumed that the circuit is good.

Connect the scan tool to the vehicle and access the "State Display" screen. From the "State Display" screen, access the "State Display Sensors" screen.

The following can be monitored in this mode:

- Adaptive fuel factor
- Added adaptive fuel
- Automatic Idle Speed (AIS) motor position
- Barometric pressure
- Battery temperature sensor
- Battery voltage
- Charging system goal
- Coolant temperature
- Coolant temperature sensor
- Engine speed
- Fault #1 Key ON Info
- Fault #2 key ON info
- Fault #3 key ON info
- Manifold Absolute Pressure (MAP) gauge reading
- MAP sensor reading
- MAP sensor voltage
- Minimum air flow speed
- Minimum throttle
- Module spark advance
- Oxygen sensor signal
- Oxygen sensor state
- Speed control status
- Speed control target
- Theft alarm status
- Throttle opening
- Throttle position
- Total spark advance
- Vehicle speed

CIRCUIT ACTUATION TEST MODE

The circuit actuation test mode checks for the proper operation of output circuits and devices that the engine controller cannot test. The engine controller attempts to actuate these outputs and allows an observer to verify the operation of the component. Most of the checks in this mode provide an audible or visual indication of component operation. Unless an intermittent condition exists, if a device functions properly during its test, it can be assumed that the component and its related circuit are functioning properly. To enter circuit actuation mode, access the "Actuate Solenoid/Rly" or "Actuate Outputs" on the scan tool.

The following can be tested in this mode:

- AIS motor
- ASD fuel systems test
- Air conditioning clutch relay
- All solenoids/relays
- Alternator field
- Auto shutdown relay
- EGR solenoid
- Fuel injector #1
- Ignition coil #1
- PTU solenoid (A/T only)
- Purge solenoid
- Radiator fan relay
- Speed control servo solenoids
- Tachometer output