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.
Diagnostic Connector:
1. Connect the scan tool to the diagnostic connector located in the engine compartment near the left strut tower.
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 the ignition switch ON, OFF, ON, OFF, ON 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.
SWITCH TEST MODE
The switch inputs read by the Single Module Engine Controller (SMEC) have two recognized states (high and low). Therefore, the SMEC cannot determine the difference between a switch position and an open or shorted circuit, or a defective switch. By using the switch test mode, the present state of circuit at the SMEC is displayed. 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. To use the switch test mode, access "Read Input States" on the scan tool.
The digital display must change between 00 and 88 and the CHECK ENGINE LAMP will flash when the switch is turned ON and OFF.
The following circuits can be monitored in this mode:
- Air conditioning switch
- Brake switch
- PARK/NEUTRAL switch
CIRCUIT ACTUATION TEST MODE
The circuit actuation test mode checks for the proper operation of output circuits and devices that the Single Module Engine Controller (SMEC) cannot test. The SMEC 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:
1. Connect a scan tool to the engine diagnostic connector.
2. Access the "Diagnostic Test Mode" and wait for code 55 to display on the screen.
3. Press the Actuation Test Mode (ATM) button on the scan tool to activate the test display. If a specific test is desired, hold the button down until the desired test code appears. The computer will turn ON and OFF the circuit until the ATM button is pressed again or five minutes, whichever is less.
TEST DISPLAY CODES
01 Spark activation once every two seconds.
02 Injector activation once every two seconds.
03 Automatic idle speed control motor activation -- one pulse open, one pulse closed every four seconds.
04 Radiator fan activation -- one pulse every two seconds
05 Air conditioning cutout relay activation -- one pulse every 2 seconds.
06 Auto shutdown relay activation -- one toggle every two seconds.
07 Canister purge solenoid activation -- one toggle every two seconds.
08 Speed control vacuum and vent solenoid activation -- every two seconds.
NOTE:Speed control switch must be in the ON position for actuation to occur.
09 Wastegate solenoid activation -- one toggle every two seconds.
10 Barometric read solenoid activation -- one toggle every two seconds.
11 Alternator full field activation -- one toggle every two seconds.
SENSOR TEST MODE
The sensor test mode reads the values of seven sensors and the state of three switches. The data is then displayed on the scan tool. They are displayed either in terms of Single Module Engine Controller (SMEC) input voltage, or they are converted into engineering units. This mode provides a means by which the integrity of individual sensor circuits can be checked whether the engine is running or not.
To enter the sensor test mode:
1. Connect the scan tool to the diagnostic connector.
2. Enable the system diagnostic test mode and wait for code 55 to appear on the display.
3. Press the Actuator Test Mode (ATM) button on the scan tool to activate the sensor test mode display. If a specific sensor test is desired, hold the ATM button down until the desired test code appears.
4. Slide the Read/Hold switch to the HOLD position to display the corresponding sensor signal.
TEST DISPLAY CODES
01 Battery temperature sensor -- display number/10 equals sensor temperature.
02 Oxygen sensor voltage -- display number/10 equals sensor voltage.
03 Charge temperature sensor -- display number/10 equals sensor voltage.
04 Engine coolant temperature sensor -- display number X 10 equals temperature of sensor.
05 Throttle position sensor voltage -- display number/10 equals sensor voltage.
06 Peak knock sensor voltage -- display number equals sensor voltage.
07 Battery voltage -- display number is battery voltage.
08 Map sensor voltage -- display number/10 is sensor voltage.
09 Speed control switches:
Cruise OFF -- Display is blank
Cruise ON -- Display shows 00
Cruise SET -- Display shows 10
Cruise RESUME -- Display shows 01
10 Fault codes erase routine. Display will flash "0" for four seconds.
ENGINE PARAMETER TEST MODE
CAUTION: Be sure to apply parking brake and/or block tires prior to performing any engine running tests.
This system monitors the sensors on the vehicle that relate to operating conditions while the engine is RUNNING. The engine RUNNING test test mode may be performed while in NEUTRAL with the parking brake ENGAGED, or while driving the vehicle during a road test. When the diagnostic tool read/hold switch is in the READ position, the engine running test mode is initiated after the engine is STARTED.
To read a test code, the read/hold switch must be in the READ position and the actuator button depressed until the desired code appears. Release the actuator button and move the read/hold switch to the HOLD position. The Single Module Engine Controller (SMEC) will monitor that system and display the results to the screen.
CODE DESCRIPTION
61 Battery temperature sensor -- display number/10 equals voltage.
62 Oxygen sensor -- display number/10 equals voltage.
63 Intake charge temperature sensor -- display number/10 equals voltage.
64 Engine coolant temperature sensor -- display number X 10 equals degrees F.
65 Throttle position sensor -- display number/10 equals voltage.
67 Battery voltage sensor -- display is battery voltage.
68 Manifold vacuum/pressure sensor -- display is in Hg (PSIG).
69 Minimum throttle position sensor -- display number/10 equals voltage.
70 Minimum airflow speed -- display number X 10 equals rpm.
71 Vehicle speed sensor -- display is mph.
72 Engine speed sensor -- display number X 10 equals rpm.