SECTION 5 -- DIAGNOSTIC CODES

WTEC III ELECTRONIC CONTROLS TROUBLESHOOTING MANUAL

SECTION 5 -- DIAGNOSTIC CODES

DIAGNOSTIC CODE MEMORY

Diagnostic codes are logged in a list in memory (sometimes referred to as the queue), listing the most recently

occurring code first and logging up to five codes. The codes contained in the list have information recorded as

shown in the table below (codes are examples). Access to the code list position, main code, subcode and active

indicator is through either the shift selector display or the Pro-Link diagnostic tool. Access to ignition cycle

counter and event counter information is through the diagnostic tool only. Further detail on the use of Pro-Link

9000 DDR is presented in Appendix G of this manual.

Table 51. Code List

Code List

Ignition Cycle

Position

Counter

Main Code

Subcode

Active Indicator

Event Counter

YES

Displayed on shift selector and diagnostic tool

YES = LED indicator

Not available on shift selector display

d = "diagnostic"

illuminated

The following paragraphs define the different parts of the code list.

Code List Position. The position which a code occupies in the code list. Positions are displayed as

"d1" through "d5" (Code List Position #1 through Code List Position #5).

Main Code. The general condition or area of fault detected by the ECU.

Subcode. The specific area or condition related to the main code in which a fault is detected.

Active Indicator. Indicates when a diagnostic code is active. The MODE indicator LED on the shift

selector is illuminated or the diagnostic tool displays YES.

Ignition Cycle Counter. Determines when inactive diagnostic codes are automatically cleared from

the code list. The counter is increased by one each time a normal ECU power down occurs (ignition

turned off). Inactive codes are cleared from the code list after the counter exceeds 25.

Event Counter. Counts the number of occurrences of a diagnostic code. If a code is already in the

code list and the code is again detected, that code is moved to position d1, the active indicator is

turned on, the Ignition Cycle Counter is cleared, and 1 is added to the Event Counter.

52.

CODE READING AND CODE CLEARING

Diagnostic codes can be read and cleared by two methods: by using the Pro-Link 9000 diagnostic tool or by

entering the diagnostic display mode and using the shift selector display. The use of the Pro-Link 9000 diagnostic

tool is described in the instruction manual furnished with each tool and briefly in Appendix G of this manual. The

method of reading and clearing codes described in this section refers to entering the diagnostic display mode by the

proper button movements on the shift selector.