ASE A2 cheat sheet

Fluid level is checked with the transmission at operating temperature, engine running, vehicle level, and the range selector cycled per OEM procedure; burned smell or clutch/metal debris points to internal distress.

A stall test holds the brakes at wide-open throttle in Drive and Reverse; engine speed above specification in one range suggests a slipping clutch or band or low apply pressure, while low stall speed can indicate engine or converter trouble.

Line pressure test: compare measured pressure at the OEM port and RPM to specification; low pressure can come from pump wear, regulator leakage, or filter restriction, and high pressure from a stuck regulator or solenoid.

Gear ratio from scan data = input shaft speed divided by output shaft speed; an actual ratio that differs from the commanded ratio indicates slip or a speed-sensor/wiring error.

TCC slip = engine speed minus input shaft speed while the torque converter clutch is commanded on; excessive positive slip indicates converter clutch or hydraulic control fault.

Retrieve TCM/PCM DTCs and freeze-frame data before circuit tests; diagnose electrical codes by checking power, ground, resistance, and short-to-voltage rather than replacing solenoids.

Manual range test: if a gear works in manual but not in Drive, suspect electronic or hydraulic shift control; if it slips in all ranges, suspect common pressure or mechanical fault.

A road test should verify garage shifts, upshifts and downshifts, TCC apply and release, and forced downshifts; compare speed, throttle, and temperature to the OEM shift schedule.

ATF check: engine running, operating temperature, level ground, Park or Neutral per OEM, cycle ranges, then check level within the specified time before fluid drains back.

Use only the fluid specification printed for that unit; incorrect ATF or CVTF changes friction coefficient and can cause shudder, flare, or converter clutch failure.

Pan magnet fine gray fuzz is normal wear; large metallic chunks, brass or bronze particles, or heavy clutch material indicate impending failure.

Band adjustment: tighten the adjusting screw to specified torque, then back it off the specified number of turns; over-tightening can prevent drum release and burn the band.

Shift linkage adjustment positions the manual valve and range sensor together; use the OEM alignment pin or neutral mark, then verify Park/Neutral start and reverse lamps.

After valve body, solenoid, or clutch repair, clear or adapt transmission learn values per OEM and perform a relearn drive cycle so shift quality adapts.

Transmission cooler flow should be checked in the OEM specified direction; low flow can be a clogged cooler, kinked line, or failed cooler check valve.

Pan bolts are tightened in a crosswise pattern to specified torque; over-torque distorts the pan flange and causes leaks.

Before in-vehicle valve body work, verify battery voltage and disconnect the negative cable per OEM; static electricity can damage the TCM or solenoids.

Solenoid circuit test: measure resistance across solenoid pins and voltage drop on the ground side; compare to OEM; an open or shorted coil requires replacement, not just relearn.

When removing the valve body in vehicle, keep it flat and tag bolt locations; trapped check balls, mismatched bolts, or omitted gaskets cause no-move or pressure faults.

Input and output speed sensors are tested for resistance, AC voltage while cranking or driving, and debris; metal shavings on the sensor can mimic an internal slip fault.

Transmission range sensor adjustment must match the manual lever detent; incorrect adjustment can cause no-start, wrong gear engagement, or reverse lamp errors.

Axle seal and cooler line repairs require supporting the transmission and avoiding load on the differential seal; verify fluid level and leak after repair.

TCM replacement usually requires programming and configuration; a used TCM may not communicate or may carry the wrong calibration.

In-vehicle servo or accumulator repair: inspect the bore and seal, lubricate seals with ATF, and verify apply and release with a pressure gauge or scan data.

Before disassembly, drain fluid, mount the unit on a bench stand, and tag valve body, servo, and clutch parts by location; mixing parts can change clearances and shift quality.

Clutch pack clearance is measured with a dial indicator or feeler gauge under specified apply pressure; excessive clearance causes flare, and too little causes drag or burn.

Air-check each clutch and band apply circuit with regulated air; listen for leak paths and confirm piston return; no apply suggests a torn seal, cracked piston, or blocked passage.

Torque converter replacement is required when hub runout exceeds specification, the converter balloons, or debris contaminates the converter; flushing may not remove clutch material.

Pump rotor or gear clearance and end clearance must be measured with a feeler gauge and straightedge; a worn pump causes low line pressure and delayed engagement.

Endplay is set with selective shims or thrust washers; too little endplay can seize, and too much causes noise and misalignment.

Valve body flatness is checked with a straightedge; a warped body causes cross leaks and harsh or no shifts; check valves and check balls must be in correct locations.

Reassembly: lubricate seals and bearings with ATF, use seal protectors, and verify all clutch clearances and endplay before installing.