Reading and Clearing Diagnostic Trouble Codes

Connect the test lamp before cycling the ignition switch from RUN to OFF. When performing the tests, observe the time when the ignition switch is cycled to ensure that the module vent solenoid timer and compressor timer are operating properly. Tests must be performed without disconnecting the harness connector at the module, unless stated to do so within the individual testing procedures (diagnostic charts). Review monitor lamp service function. The compressor relay, vent solenoid and height sensor have internal diodes for electrical noise suppression, and therefore are polarity sensitive. Care must be taken when servicing these components not to switch battery feed (positive) and ground (negative) circuits or component damage will result. Specific component pinpoint diagnostic resistance checks require using an analog volt-ohmmeter only. Other type volt-ohmmeters will indicate false voltage/resistance checks.