4L65E Internal Wiring Harness 2006-2008, new and ready to install. Fits the 4L65E. Ships fast from the USA.
A 2006, 2007 or 2008 GM truck or SUV with the 4L65E that sets an input speed sensor code next to a solenoid code is a strong candidate for a new internal harness. This listing is a new internal wiring harness for 2006-2008 4L65E transmissions in 6.0L and 5.3L Silverado, Sierra, Tahoe, Yukon, Suburban and Avalanche models, listed with reference number 24234121 and priced at $60.99. These model years have their own electrical layout inside the pan, which is why the year range on this page matters.
2006 was a major change year for the 4L60E family. An internal input speed sensor was added on the pump to read teeth on the input shaft, and the internal harness and pass-through connector were revised to carry its signal. The rest of the layout carried over from earlier years: shift solenoids A and B, the pressure control solenoid that sets line pressure, the on/off and PWM converter clutch solenoids, the on/off 3-2 control solenoid and the pressure switch manifold that reports manual valve position. The harness also returns the fluid temperature signal. Because the computer now compares input speed with output speed, a failing speed sensor circuit in this harness can upset shift quality and line pressure control, not just set a code.
Not every speed sensor code is wiring. Mismatched pump covers and input shafts, common after a partial rebuild, can also set P0716 or P0717, so ask what was replaced before you assume the harness.
Pull the case connector and inspect it for fluid and bent pins. Measure each solenoid circuit and the speed sensor circuit from the transmission side while flexing the harness at the case and at the pump. An open or jumping reading confirms a wiring fault. The 4L65E input and output speed sensor guide covers the sensor checks, and the Tahoe shift problems guide helps separate an electrical fault from valve body wear on the SUVs.
This harness is listed for 2006-2008 4L65E units. Two details deserve a close look. First, GM did not give every model the speed sensor in 2006, and some units have a plug in the sensor hole instead, so check whether your old harness has a speed sensor lead. Do not leave that plug out of the pump, because it causes a loss of converter charge pressure and a no-move condition. Second, the reference number 24234121 is also cross-referenced to the 2009-and-later harness used with the internal mode switch. A 2009 harness connects to a range sensor rather than a pressure switch manifold and has no 3-2 solenoid plug, so it is not a direct swap into a unit that still has the manifold. Compare the plugs on your old harness with this one, or send us your year and VIN and we will confirm it before it ships. Every other part for this unit is in the 4L65E collection.
| Fits | 4L65E 2006-2008 |
| Part type | Internal Wiring Harness |
| Condition | New |
| Brand | OEM |
| Reference | 24234121 |
| Ships | From the USA |
| Warranty | 1-year |
For 2006 GM added an internal input speed sensor on many 4L60E-family units, and the internal harness and pass-through connector were revised to carry it. The pressure switch manifold and 3-2 solenoid stayed until 2009.
Some 2006-2008 models did not get the sensor and use a plug instead. Compare your old harness with this one before installing, and never leave the plug out, because it causes lost converter charge pressure and a no-move condition.
2009 and later units dropped the 3-2 solenoid and the pressure switch manifold in favor of an internal mode switch, so the plug layout is different. Match the connectors on your old harness, or send us your year and VIN to confirm.
Yes, an open or intermittent speed sensor circuit in the harness can set P0717. So can a failed sensor or mismatched pump and input shaft parts after a rebuild, so test the circuit before replacing parts.
GM specifies Dexron VI for the 4L65-E. Check the level hot after the road test.
