W T E C I I I E L E C T R O N I C C O N T R O L S T R O U B L E S H O O T I N G M A N U A L
CHECK TRANS LIGHT
When the ECU detects a serious fault, the CHECK TRANS light (usually located on the vehicle instrument panel)
illuminates and action is automatically taken to protect operator, vehicle, and the transmission. A diagnostic code will
nearly always be registered when the CHECK TRANS light is on; however, not all diagnostic codes will turn on the
CHECK TRANS light. Codes related to the CHECK TRANS light are detailed in the code chart (refer to Section 6).
Illumination of the CHECK TRANS light indicates that a condition was detected that requires service attention.
Operation may or may not be restricted but even when restricted will allow the vehicle to reach a service assistance
location. Depending upon the cause for the CHECK TRANS light illumination, the ECU may or may not respond
to shift selector requests. The transmission may be locked in a range. That range will be shown on the shift selector
display. Both upshifts and downshifts may be restricted when the CHECK TRANS light is illuminated. Seek
service assistance as soon as possible.
Each time the engine is started, the CHECK TRANS light illuminates briefly and then goes off. This momentary
lighting shows the light circuit is working properly. If the light does not come on during engine start, request
DIAGNOSTIC DATA READER (Figure 21)
The current Diagnostic Data Reader (DDR) is the Pro-Link® 9000 diagnostic tool which is available through
Kent-Moore Heavy-Duty Division. A portable microcomputer-based receiver/transmitter/display unit, the
Pro-Link® transmits and receives data to and from the ECU, processes the data, and displays appropriate
information. Use the Pro-Link® during installation checkout and troubleshooting. There is a new Pro-Link®
cartridge needed for use with WTEC III controls. The new Multi-Protocol Cartridge (MPC) contains a
programmed PCMCIA card which allows for reprogramming of GPI/GPO packages. Reprogramming includes
selection of a GPI/GPO package, enabling/disabling of wires and modification of certain data parameters.
Operating instructions are supplied with each Pro-Link® and further information is also included in Appendix N of
this manual. Connect the Pro-Link® 9000 to the diagnostic connector provided in the selector wiring harness.
Tool part numbers for the Pro-Link® are as follows:
Diagnostic Kit J 38538D + J 38500313 (PROM Update) = J 38538E
Diagnostic Cartridge J 38500-302 + J 38500313 = J 38500303
MPC J 385001500C
PCMCIA (Diagnostic And Reprogramming) J 385001700B
PCMCIA (Diagnostic Only) J 385001800A
The new MPC is usable with WTEC II controls but the old WTEC II reprogramming cartridge will
not display the WTEC III new information. The new MPC must be used to reprogram WTEC III
Figure 21. Pro-Link
9000 Diagnostic Tool
SECTION 2 DEFINITIONS AND ABBREVIATIONS