EDI DIAGNOSIS
SERVICE MANUAL NUMBER 22
Page 5E-10
90-860074--1 FEBRUARY 2002
Intermittent Problems and Malfunction Indicator Lamp
In the case of an intermittent problem, the Malfunction Indicator Lamp will light for ten
seconds and then will go out. However, the corresponding code will be stored in the memory
of the ECM. When unexpected codes appear during the code reading process, one can
assume that these codes were set by an intermittent malfunction and could be helpful in
diagnosing the system.
An intermittent code may or may not reset. IF IT IS AN INTERMITTENT FAILURE, A
DIAGNOSTIC CODE CHART IS NOT USED. Consult the Diagnostic Aids information on
the same topic as the diagnostic code discussion. Troubleshooting The EDI System also
covers the topic of Intermittents. A physical inspection of the applicable sub-system most
often will resolve the problem.
Reading Codes
The provision for communicating with the ECM is the Data Link Connector (DLC) connector.
It is part of the EDI engine wiring harness and is a 4-pin connector, of which only 3 pins are
currently being used. The connector is mounted on the Electrical Box and is electrically
connected to the ECM. It is used in the assembly plant to receive information that the engine
is operating properly before it leaves the plant.
The code(s) stored in the ECM’s memory can be read by counting the number of flashes
of the light on a Blink Code Tool when connected or by using a scan tool, a diagnostic
scanner that plugs into the DLC connector.
75395
a
b
DLC Connector
a -
Electrical Box
b -
DLC Connector
