G3400 Engines (EIS) Caterpillar

Diagnostic codes alert the operator that a problem in the electronic system has been detected. Diagnostic codes also indicate the nature of the problem to the service technician. Diagnostic codes can be generated by the control module for the Electronic Ignition System (EIS) and by the Electronic Control Module (ECM) for the air/fuel ratio control. Diagnostic codes may be viewed on these electronic service tools:

Digital Diagnostic Tool (DDT) - The DDT is a compact device that includes a keypad and a screen.

Caterpillar Electronic Technician (ET) - Cat ET is a software program that is designed to run on a personal computer.

The Diagnostic codes consist of the module identifier (MID), the component identifier (CID), and the failure mode identifier (FMI).

Module Identifier (MID) - The MID is a code with two or three digits that indicates the electronic module which generated the diagnostic code. The MID for the EIS control module is 14.

Component Identifier (CID) - The CID is a number with three or four digits. The CID indicates the component that generated the code. For example, the CID number 0317 identifies the manifold air pressure sensor.

Failure Mode Identifier (FMI) - The FMI is a two digit code that indicates the type of failure. Table 1 is a list of the failure mode identifiers that are adapted from the "SAE J1587" standard.

Table 1

Failure Mode Identifiers
FMI	Description of Failure
00	"Data valid but above normal operating range"
01	"Data valid but below normal operating range"
02	"Data erratic, intermittent or incorrect"
03	"Voltage above normal or shorted high"
04	"Voltage below normal or shorted low"
05	"Current below normal or open circuit"
06	"Current above normal or grounded circuit"
07	"Mechanical system not responding properly"
08	"Abnormal frequency, pulse, or period"
09	"Abnormal update"
10	"Abnormal rate of change"
11	"Failure mode not identifiable"
12	"Bad device or component"
13	"Out of calibration"
14	"Not used"
15	"Not used"

When a diagnostic code is generated, an indicator on the engine is activated in order to alert the operator. If the condition that generated the code is momentary, the code may be cleared with the "Diagnostic Reset Switch". If the code remains on the display, the code is active. An active diagnostic code represents a problem with the electronic control system. Correct the problem as soon as possible.