Allison B 400 - Diagnostic Tree - WT Series Hydraulic System

Copyright © 1998 General Motors Corp. M–1
WTEC II ELECTRONIC CONTROLS TROUBLESHOOTING MANUAL
APPENDIX M — DIAGNOSTIC TREE — WT HYDRAULIC SYSTEM
Figure M–1. Diagnostic Tree — WT Series Hydraulic System With Gauges
C1 LATCH
VALVE
INOPERATIVE
SELECT THIRD
RANGE,
ENGINE @ IDLE
SELECT SECOND
RANGE,
ENGINE @ IDLE
SELECT FOURTH
RANGE,
ENGINE @ HIGH IDLE
C1
CLUTCH
OFF
C1
LATCH VALVE
INOPERATIVE
C3
CLUTCH
OFF
SELECT FIFTH
RANGE,
ENGINE @ IDLE
C5
SOLENOID
INOPERATIVE
C4
SOLENOID
INOPERATIVE
C5
SOLENOID
INOPERATIVE
C3
SOLENOID
INOPERATIVE
FORWARD
SOLENOID
INOPERATIVE
SELECT FIRST
RANGE,
ENGINE @ IDLE
C2
CLUTCH
OFF
C5
CLUTCH
OFF
C1
SOLENOID
INOPERATIVE
NO
CLUTCHES
APPLIED
FORWARD
SOLENOID
INOPERATIVE
C2 LATCH
VALVE
INOPERATIVE
NO
CLUTCHES
APPLIED
HOT
MAIN LESS
THAN 150
PSI
HOT MAIN
CIRCUIT
LEAK
C3
CLUTCH
APPLIED
C1
CLUTCH
APPLIED
C5
CLUTCH
APPLIED
C4
CLUTCH
APPLIED
LOW CONTROL
MAIN
CTL =
1
⁄3 CL PR
C1 & C2
PRESSURE
LOW
C2
PRESSURE
LOW
C2
SOLENOID
INOPERATIVE
C1
SOLENOID
INOPERATIVE
C1
PRESSURE
LOW
C4
CLUTCH
OFF
C4
SOLENOID
INOPERATIVE
C2
SOLENOID
INOPERATIVE
C2
CLUTCH
ON
C3
SOLENOID
INOPERATIVE
PARKING BRAKE ON,
START ENGINE
INSTALL PRO-LINK
®
AND SWITCH TO
CLUTCH TEST MODE
INSTRUMENT
MAIN & C1–C5
WITH 300 PSI
PRESSURE
GAUGES
SELECT
REVERSE
RANGE,
ENGINE @ IDLE
ALL OTHER CONDITIONS
ALL OTHER CONDITIONS
ALL OTHER CONDITIONS
ALL OTHER CONDITIONS
ALL OTHER CONDITIONS
HYDRAULIC
SYSTEMS
OK
V01102.02
DIAGNOSTIC TREE
WT SERIES HYDRAULIC SYSTEM
USING PRESSURE GAUGES AT MAIN & C1–C5
C3
CLUTCH
ON
C3
CLUTCH
OFF
C5
CLUTCH
ON
C5
CLUTCH
OFF
C2 LATCH VALVE
OR FWD SOLENOID
INOPERATIVE
NOTE: Fifth range not attainable if
ECU is programmed for ranges 1 – 4 only.
SELECT
NEUTRAL
RANGE,
ENGINE @ IDLE,
ENABLE CLUTCH
TEST MODE