For 1990-2009 cars

# SECOND GEAR STARTS DIAGNOSIS FOR GOVERNOR CIRCUIT

#### MODELS/YEARS: 1984-87 MODELS WITH THM 440-T4 TRANSAXLES

#### Bulletin Covers:

A 1984-87 vehicle equipped with a THM 440-T4 (Figure 1) may start out in 2nd gear instead of 1st gear. This condition could occur intermittently or all the time.

#### Service Action:

High line pressure could be a cause by holding too much governor pressure and not allowing the 1-2 shift valve to downshfft. Check line pressure and governor pressure. Governor pressure should be below 3.0 PSI at 0 mph.

If governor pressure is okay, the 1-2 shift valve (331) may be stuck in the upshifted position. Remove the control valve assembly and check for a sticking 1-2 shift valve (331),1-2 throttle valve (332), or the 1-2 throttle valve spring (333) caused by the 1-2 throttle valve bushing retainer (390) pushed in too far. The retainer should be installed flush with the machined surface of the valve body. (Figure 2)

Service Manual Reference:

Refer to the THM 440-T4 (ME9) automatic transaxle unit repair section in the appropriate service manual.

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.