With Scan Tool

Fig. 2 Tech 1 Scan Tool Key Functions:

Fig. 3 Diagnostic Process Using Tech 1 Scan Tool (Part 1 Of 3):

Fig. 3 Diagnostic Process Using Tech 1 Scan Tool (Part 2 Of 3):

Fig. 3 Diagnostic Process Using Tech 1 Scan Tool (Part 3 Of 3):

When using the following diagnostic procedure refer to Figs. 2 and 3 for ``Scan'' tool functions. For diagnostic circuit check, diagnostic charts and code identification refer to DIAGNOSTIC CHARTS.
1. Use a TECH 1 or equivalent scan tool to read all current and history diagnostic codes. There is no provision for flash code diagnosis, fault codes can only be read using a bidirectional ``Scan'' tool. Do not clear codes unless directed to do so.
2. Read all ``CODE HISTORY'' data. Note codes stored and their frequency of failure. Specifically note last failure that occurred and conditions present when this failure occurred.
3. Perform vehicle preliminary inspection as follows:
a. Check master cylinder for proper fluid level.
b. Check ABS hydraulic modulator for any fluid leaks or wiring damage.
c. Check brake components at all four wheels, ensure that no drag exists and that brake apply operation is satisfactory.
d. Check for any wheel bearing wear or damage.
e. Check wheel speed sensors for correct air gap, solid sensor attachment, damaged tooth ring, damaged wiring or connectors.
f. Check for proper outer CV joint alignment and operation.
g. Ensure tires meet legal tread depth requirements.
4. If no codes are present or if mechanical failure codes are present, perform AUTOMATED SELF-DIAGNOSING MODULATOR under COMPONENT TESTING using the ``Scan'' tool.
5. If failure is intermittent and not reproducible using procedures as described under INTERMITTENTS & POOR CONNECTIONS, proceed as follows:
a. Test drive vehicle using the automatic snapshot feature of the ``Scan'' tool.
b. Perform normal acceleration, stopping and turning maneuvers. If failure does not reproduce, proceed to step c.
c. Perform an ABS stop from approximately 30-50 mph while triggering on any ABS code. If failure still does not reproduce, proceed to step d.
d. Refer to ONBOARD DIAGNOSTIC INFORMATION for information on ``CODE HISTORY.''
6. After all system failures have been corrected, clear trouble codes as described under CLEARING CODES.