Most 4L60E "no 3rd gear" or "harsh 2-3 shift" calls come down to a $30 solenoid, not a teardown. The trick is knowing which solenoid is failing before you commit to dropping the pan. Here are the five symptoms that point you straight to it.
Watch the scan tool: if commanded EPC current doesn't match actual line pressure (gauge on the tap), the EPC is gone. ~$30-50 part. 30-min replacement with the pan dropped.
View on ShopifyP0753 = SS1 (1-2) electrical. P0758 = SS2 (2-3) electrical. Replace both as a set if one is gone — they're the same part and they fail together. Sold as 2-piece kits.
View on ShopifyP0741 code in 90% of cases. Try Dexron VI fluid swap first — TCC valves are friction-sensitive. If shudder persists after fluid swap, replace the TCC PWM solenoid + apply valve.
View on ShopifyAt 100K+ miles, all 4L60E solenoids are equally worn. Replacing one and leaving the others is a warranty comeback waiting to happen. Master kit covers all 7 in one purchase.
View on ShopifyNot technically solenoids but in the same electrical-failure category. ISS + OSS sold as a matched pair (they fail in pairs). Replace both at the same time.
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