Copyright © 1998 General Motors Corp.
1–1
W T E C I I E L E C T RO N I C C O N T RO L S T RO U B L E S H O OT I N G M A N UA L
1–1.
TRANSMISSION
The World Transmission Electronic Controls WTEC II system features closed-loop clutch control to provide
superior shift quality over a wide range of operating conditions. MD 3000 (except 3070), HD 4000, and B Series
configurations can be programmed to have up to six forward ranges, neutral, and one reverse range. The MD 3070
has seven forward ranges and one reverse range. Figures 1–1 and 1–2 show electronic control unit components.
WTEC II Electronic Controls consist of the following components:
•
Basic or Max Feature Electronic Control Unit (ECU)
•
Pushbutton or Lever Shift Selectors (remote or integral to the ECU)
•
Optional Secondary Shift Selector
•
Engine, Turbine and Output Speed Sensors
•
Throttle Position Sensor (TPS) (or electronic engine throttle signal or PWM signal)
•
Control Module (Electro-Hydraulic Valve Body)
•
Wiring Harnesses
•
Vehicle Interface Module (VIM)
•
Optional Retarder Controls
•
TransID Feature
NOTE:
Model Year ’94 and earlier WT Series Electronic Controls operate on 12VDC. Vehicles with a 24VDC
system require a voltage equalizer or converter to supply 12V to the electronic control system. Model
Year ’95 and later transmissions operating on 24VDC require a 24V VIM and a 24V wiring harness
which includes shielding for the turbine and output speed sensors.
Figure 1–1. WTEC II Electronic Control Components (Units Produced Before 9/94)
7
8
9
4
5
6
1
2
3
0
EN
TE
R
=
x
–
+
–
OPTIONAL
DEUTSCH DDR
CONNECTOR
INTEGRAL ECU/
SHIFT SELECTORS
REMOTE
ECU
RETARDER
MODULATION
REQUEST (RMR)
SENSOR CONNECTOR
ELECTRONIC
CONTROL
UNIT
(ECU)
CONNECTORS
DIAGNOSTIC
DATA READER (DDR)
CONNECTOR
PRO-LINK
®
DIAGNOSTIC TOOL
J 38538-A
THROTTLE
POSITION
SENSOR
VEHICLE
INTERFACE
MODULE
(VIM)
MD/B 300/B 400
RETARDER CONNECTOR
(INCLUDES OUTPUT
SPEED SENSOR)
MD 3070
TRANSFER CASE
CONNECTOR
OUTPUT SPEED
SENSOR
*CONNECTOR
TRANSMISSION
CONNECTOR
ENGINE
SPEED
SENSOR
CONNECTOR
V01634
TPS
CONNECTOR
TURBINE
SPEED
SENSOR
CONNECTOR
(HD/B 500)
HD/B 500
RETARDER
TEMPERATURE
SENSOR
CONNECTOR
REMOTE SERIAL
INTERFACE
CONNECTOR
REMOTE
PUSHBUTTON SHIFT
SELECTOR
STRIP PUSHBUTTON
SHIFT SELECTOR
REMOTE
LEVER SHIFT
SELECTOR
RETARDER “K”
CONNECTOR
(HD/B 500)
HD/MD/B RETARDER
ACCUMULATOR “H”
SOLENOID
CONNECTOR
OPTIONAL
BULKHEAD
CONNECTOR
WIRING
HARNESS
NOTE: Illustration is not to scale.
*All HD/B 500 models
All Non-Retarder MD/B 300/B 400 models
12
D
N
R
D
N
R
VEHICLE
INTERFACE
WIRING
(VIW)
CONNECTOR
S
ECTION
1 — GENERAL DESCRIPTION