BEGINNING THE TROUBLESHOOTING PROCESS

WTEC III ELECTRONIC CONTROLS TROUBLESHOOTING MANUAL

BASIC KNOWLEDGE

Inspect all connector terminals for damage. Terminals may have bent or lost the necessary tension to

maintain firm contact.

Clean dirty terminals or connectors with isopropyl alcohol and a cotton swab, or a good quality, non-

residue, non-lubricating, cleaning solvent such as LPS Electro Contact Cleaner or LPS NoFlash

Electro Contact Cleaner.

The cleaning solvent must not be chlorine based, contain petroleum distillates, or conduct

electricity. The cleaning solvent should evaporate quickly to prevent the possibility of

condensation within the connectors. Always blow or shake any excess cleaner from the

CAUTION:

connector before assembling it to its mating connector or hardware. Cleaner trapped in the

connector can affect the connector seal. (Refer to SIL 17-TR-94 for detailed information

on the recommended cleaners.)

Care should be taken when welding on a vehicle equipped with electronic controls. Refer

CAUTION:

to Appendix E, Paragraph 11.

Diagnostic codes displayed after system power is turned on with a harness connector disconnected, can

be ignored and cleared from memory. Refer to Section 5, Diagnostic Codes, for the code clearing

procedure.

35.

BEGINNING THE TROUBLESHOOTING PROCESS

NOTE:

Whenever a transmission is overhauled, exchanged, or has undergone internal repairs, the Electronic

Control Unit (ECU) must be "RESET TO UNADAPTED SHIFTS." See Service Information Letter

16-WT-96, Revision A availability from Freightliner dealer for further details.

Begin troubleshooting by checking the transmission fluid level and ECU input voltage. Remember

that some problems may be temperature related. Do troubleshooting at the temperature level where

the problem occurs. Check diagnostic codes by:

Using the shift selector display. (See Paragraph 52 for code reading.)

Using the Pro-Link 9000 diagnostic tool.

When a problem exists but a diagnostic code is not indicated, refer to Transmission and Driveline Trou-

bleshooting WP 0011 00 for a listing of various problems, their causes, and remedies.

If a diagnostic code is found in the ECU memory, record all available code information and clear the

active indicator (refer to Section 5).

Test drive the vehicle to confirm a diagnostic code or performance complaint.

If the code reappears, refer to the Diagnostic Code section (Section 5) and the appropriate code

chart. The Diagnostic Code section lists diagnostic codes and their description. Locate the

appropriate troubleshooting chart and follow the instructions.