Diagnostic Strategies

1987-89

Refer to ``Pre-Test Conditions'' before performing procedure.

When battery voltage is low, no detection of failure is possible. Ensure battery is fully charged prior to testing. Ensure not to disconnect battery ground cable prior to testing as the malfunction code will be erased. To diagnose the oxygen sensor, operate vehicle until engine coolant is at normal operating temperatures. Do not turn ignition switch Off after vehicle operation as the memory may be erased. After testing, disconnect battery ground cable for approximately 15 seconds or more to erase failure code.