Hummer H1 Service Manual page 242

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®
NOTE: Some corrections indicated in the table below may not be allowed on vehicles covered under the provisions of the war-
ranty policy. The proper correction may be transmission replacement. Contact the AMG warranty department for direction in such
cases.
Problem
Fluid Leaking 1. Transmission overfilled.
Out of Vent
and/or Foaming
2. Wrong or contaminated fluid.
3. Air entering fluid due to cross leakage at
4.
Transmission 1. Low fluid level.
Overheat
2. Oil cooler problem:
3.
4.
5.
6.
7.
Line Pressure 1. Oil pump problem:
Too High or
Too Low
2.
3.
05745159
TRANSMISSION DIAGNOSIS GUIDE
Potential Cause
improperly seated pump cover or filter.
Transmission overheat. Caused by:
• low fluid level
• blocked oil cooler
• full load hot climate temperature operation
• converter clutch valve or spring failure
• converter stator locked (seized) and will not
free wheel at coupling speed
• Fins blocked with dirt, debris
• cooler partially plugged
• cooler (or lines) leaking
Converter clutch stuck in applied position.
Converter clutch valve, limit valve, or enable
valve or spring failure.
Oil pump or body seal not seated causing
cross leakage. May be accompanied by fluid
foaming and leakage out vent.
Pressure regulator valve stuck in high demand
position.
Converter stator clutch seized (locked).
Engine overheat may also occur.
• loose PCM connection
• seals failed
• gears damaged
• bushing worn, scored
• pressure regulator valve or spring fault
• reverse/boost valve fault
• pressure relief spring collapsed, broken
• loose pump bolts
Pressure control solenoid failed OFF or ON.
TCM/PCM fault.
Transmission/Transfer Case
Correction
1. Drain Excess Fluid off through fill tube. Use
suction gun and small diameter plastic or
teflon tubing.
2. Drain and change fluid and filter. May also be
necessary to remove and drain converter.
3. Reseat filter. Remove transmission and reseat
pump if necessary.
4. Correct low fluid level and check for leaks.
Reduce engine/transmission load. Replace
transmission if clutch valve or spring
condition exists. Replace plugged, damaged
cooler.
1. Add fluid and check for leaks.
2. Clean dirt/debris with water spray. Replace
leaking or plugged cooler. Replace leaking
cooler lines or fittings.
3. Replace converter.
4. Replace transmission.
5. Remove pump and replace seal. Be sure pump
body is properly seated.
6. Remove oil pump and free up valve.
7. Replace converter.
1. Repair loose connection. Replace transmission
if pump is damaged.
2. Replace solenoid
3. Replace TCM/PCM.
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