Nine-piece solenoid set with internal wiring harness for 1997-2003 GM 4L60E and 4L65E units, covering shift, TCC, EPC and 3-2 control in one drop.
If your 1997-2003 Silverado, Sierra, Tahoe, Suburban, Yukon, S10 or Escalade is stuck in one gear, banging into second, refusing to lock the converter on the highway, or setting P0751, P0753, P0758 or P1860, the parts living on top of the valve body are the usual suspects. This nine-piece kit replaces the whole electrical side of a 4L60E or 4L65E in those years in one pan drop: shift solenoid A, shift solenoid B, the TCC on/off solenoid, the TCC PWM solenoid, the EPC pressure control solenoid, the 3-2 downshift solenoid and the internal wiring harness that runs them all back to the case connector. Reference OE numbers on the listing are 24212327, 10478120, 24227747 and 12121299.
By 1997 GM had settled the 4L60E into the electrical layout it kept through 2005. The two on/off shift solenoids are switched in four combinations to pick a gear: both on for 1st, A off and B on for 2nd, both off for 3rd, and A on with B off for 4th. That is why one weak shift solenoid shows up as a wrong-gear complaint rather than a single bad shift. The EPC solenoid is the only one the computer varies continuously; it trims line pressure and decides whether each shift lands firm or soft. The converter clutch uses two parts: the on/off solenoid enables lockup and the PWM solenoid controls how fast the clutch applies, which matters on these years because GM moved trucks to a slip-controlled converter strategy in 1998. The 3-2 solenoid manages the downshift timing when you step into the throttle at speed. All of them are fed through the internal harness, so a cracked or chafed harness can mimic a failed solenoid.
Do the electrical checks at the case connector first. ATRA's resistance chart for this transmission lists both shift solenoids at roughly 20-40 ohms and the pressure control solenoid at 3.5-8.0 ohms; a reading far outside that, or one that changes when you flex the harness, tells you which circuit has failed. ATRA has also documented a poor crimp on a shared circuit terminal setting any combination of P0740, P0753, P0758, P0785 and P1860, so check terminals and the feed before you blame every solenoid. Our guide to shift solenoids A and B and codes P0753 and P0758 walks through the pin tests, and the TCC solenoid and P0740 guide covers the lockup side. If every circuit reads correct and the shift problem stays, the valve body bores are the next suspect, not the solenoids.
The listed fitment is GM 4L60E and 4L65E transmissions in 1997-2003 rear-wheel-drive and four-wheel-drive trucks, vans and SUVs. The solenoid lineup did not change across these years, but harness routing and connector details were revised around the 2003 model year, so treat 2003 as a year to double-check. Lay your old harness next to the new one before you bolt anything down and confirm the connector shape and the number of solenoid plugs match. If you are unsure, send us your year and VIN and we will confirm it before it ships. You can see every part we carry for this transmission on the 4L60E parts page.
This is a pan-down job with the transmission left in the vehicle. Drain the pan, pull the filter, release the case connector from inside, then remove each solenoid and the harness. Change one solenoid at a time so nothing ends up in the wrong bore, lube every O-ring with clean Dexron VI, and route the new harness exactly where the old one sat so it cannot rub on the pan or the manual valve linkage. Torque the valve body bolts in sequence and to spec rather than by feel. A new filter and pan gasket are not included with this set, so plan to buy them; if you would rather get everything in one box, the master solenoid kit with harness, filter and gasket covers the earlier range. Refill with Dexron VI, clear codes, reset adaptive values and let the computer relearn over a few drive cycles. If the fluid came out black and full of clutch material, the solenoids were not the whole story and a 1997-2003 overhaul rebuild kit is the honest next step. Before you order, our 4L60E shift solenoid symptoms guide is worth ten minutes.
| Fits | GM 4L60E / 4L65E / 4L70E, 1997-2003 |
| Pieces | 9 including internal wiring harness |
| Covers | Shift A and B, TCC, TCC PWM, EPC, 3-2 downshift |
| Reference OE | 24212327, 10478120, 24227747, 12121299 |
| Service | Pan-down, transmission stays in vehicle |
| Condition | New |
Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
The listing covers 1997-2003, but 2003 is a year where GM revised harness details. Compare the connector and plug count on your old harness to the photos, or send us your year and VIN and we will confirm fitment before it ships.
No. This set is the nine electrical pieces including the internal harness. Buy a filter and pan gasket for your year, since the pan has to come off to install it.
You can, and single shift solenoids are sold separately. The full set makes sense on a high-mileage truck because the other solenoids and the harness have seen the same heat, and a second failure means dropping the pan again.
Dexron VI automatic transmission fluid. Lube the solenoid O-rings with the same fluid during assembly.
Clear the codes and reset the transmission adaptive values with a scan tool if you have one, then drive it gently through all gears for several cycles so the computer can relearn shift timing.
Sometimes, but on the 4L60E valve body bore wear is a common cause of TCC slip and P0741. If the TCC solenoids test good, have the valve body vacuum tested before replacing parts.
