A/T - 4L60E Harsh 1 - 2 Upshift
Information IB04-05-S007Diagnostic Information on Harsh 1-2
Upshift
Light Duty ASCENDER 2003 Information Transmission 09/01/04
Diagnostic Information on Harsh 1-2 Upshift
ISSUE DATE: SEPTEMBER 2004
Affected Vehicles
2003-2004 Isuzu Ascender (US/UT) models equipped with 4L60-E Automatic Transmissions.
Service Information
The following four (4) conditions have been found to cause the majority of consistent, harsh 1-2 shift comments.
1. Chips/Sediment/Debris/Contamination found in the valve body, 1-2 accumulator valve (see figure 1) bore, may cause the 1-2 accumulator valve to stick or hang-up.
2. Chips/Sediment/Debris/Contamination found in the valve body, 4-3 sequence valve (see figure 2) bore, may cause the 4-3 sequence valve to stick or hang-up.
3. A cracked 1-2 accumulator piston (see figure 3) that is allowing fluid to leak by.
4. Mislocated/Missing valve body-to-spacer plate check balls.
When attempting to correct a consistent harsh 1-2 shift, the four conditions listed above should be inspected as possible causes. It is important to also refer to the appropriate Service Manual for further possible causes of this condition.
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