Copyright © 1998 General Motors Corp. 8–7
GENERAL TROUBLESHOOTING OF PERFORMANCE COMPLAINTS
WTEC II ELECTRONIC CONTROLS TROUBLESHOOTING MANUAL
B
. Reduced Retarder Effect
Retarder accumulator solenoid not
being energized
Correct cause for setting these
codes: 42 26, 44 26, 45 26, or
69 26.
ECU sensing false overheat
condition
Use DDR or VOM to check retarder
temperature sensor. Replace sensor
as required.
Normal response to overheating See Table 6–7 in Section 6
(Code 61)
C
. Less Retarder Effect Than
Expected
Transmission fluid aerated due to
incorrect level
Check transmission fluid level and
correct as required.
Wrong retarder control regulator
valve spring
Check retarder charging pressure.
Change retarder control valve
regulator spring, if necessary.
See PO2454EN WT Series
Principles of Operation.
D.
Retarder Stays On
Autoflow valve not returning to
“off” position
— Autoflow valve spring weak
or broken
— Autoflow valve stuck “on”
— “K” solenoid stuck “on”
ABNORMAL ACTIVITIES OR
RESPONSES
A
. Excessive Creep in First and
Reverse Gears
Engine idle speed too high Adjust to correct idle speed —
between 500–800 rpm (refer to
Vehicle Service Manual)
B
. No Response to Shift Selector
Shift selector not properly
connected
Check shift selector response
with diagnostic tool. If no
response, check remote
connection and replace if
necessary
Using wrong selector on dual
station equipment
Use other selector
Faulty shift selector Replace shift selector
Incorrect fluid level Correct fluid level (refer to
transmission Mechanic’s Tips for
proper dipstick calibration)
Main pressure low Refer to Low Pressure section
Control spool valves sticking
(C1, C3, or C5 clutch pressure
low)
Overhaul valve body assembly
(refer to transmission Service
Manual)
Table 8–1. Troubleshooting Performance Complaints
(cont’d)
Problem
Probable Cause Suggested Remedy
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