Reading and Clearing Diagnostic Trouble Codes
The technician can display a DTC in three different ways:- a two-digit number flashed on the Malfunction Indicator (Check Engine) Lamp
- a two-digit number displayed on the vehicle odometer
- a description of the DTC can be read using the DRB scan tool
Refer to the following Charging System Diagnostic Trouble Code Descriptions chart for DTC's which apply to the charging system. Refer to the Powertrain Management/Computers and Control Systems/Testing and Inspection/Diagnostic Charts Procedures and DRB scan tool to diagnose an on-board diagnostic system trouble code.
Using DRB Scan Tool
WARNING: APPLY PARKING BRAKE AND/OR BLOCK WHEELS BEFORE PERFORMING ANY TEST ON AN OPERATING ENGINE.
1. Connect the DRB scan tool to the 16-way data link (diagnostic) connector. This connector is located in the passenger compartment, below and to the left of steering column.
2. Turn the ignition switch on, access Read Fault Screen. Record all the DTC's shown on the DRB scan tool. Observe the malfunction indicator (check engine) lamp on the instrument panel. The lamp should light for 2 seconds then go out (bulb check).
3. To erase DTC's, use the Erase Trouble Code data screen on the DRB scan tool.
Using The Malfunction Indicator Lamp (MIL)
1. Cycle the ignition key On-Off-On-Off-On within 5 seconds.
2. Count the number of times the MIL (check engine lamp) on the instrument panel flashes on and off. The number of flashes represents the trouble code. There is a slight pause between the flashes representing the first and second digits of the code. Longer pauses separate individual two digit trouble codes.
An example of a flashed DTC is as follows:
3. Lamp flashes 4 times, pauses, and then flashes 6 more times. This indicates a DTC number 46.
4. Lamp flashes 5 times, pauses, and flashes 5 more times. This indicates a DTC number 55. A DTC number 55 will always be the last code to be displayed. This indicates the end of all stored codes.
5. To erase DTC's, use the Erase Trouble Code data screen on the DRB scan tool.