300TE (124.090) L6-3.0L (103.983) (1989)
Data Link Connector: Description and Operation
On-Board Diagnostic Connector
The CIS-E control unit monitors emission control components that either provide input signals to or receive output signals from the control unit.
Malfunctions resulting from interruptions or failure of any of these components are indicated by the "Check Engine" light in the instrument cluster and
are simultaneously stored in the fault memory of the CIS-E control unit.
Fig. 61 Diagnostic Connector
The on-board diagnostic connector with push-button and light emitting diode (LED) is located on the engine compartment firewall. When the
push-button is depressed for 2 to 4 seconds (ignition ON), the LED will begin a blink impulse readout and the cause(s) of the malfunction will be
indicated by the number of blink impulses. Upon completion of the blink impulse readout, the LED remains on (does not blink). By pressing the
push-button again for 2 to 4 seconds, an additional malfunction blink impulse will begin (if present). If no further malfunctions are stored in the fault
memory the CIS-E control unit will be switched over to the on-off ratio readout.