Harsh or slipping shifts: Codes, Causes & Fixes

Harsh, delayed or slipping shifts in an automatic transmission often trace back to low or degraded fluid, a faulty shift or pressure control solenoid, a speed sensor problem or adaptive shift values that need relearning. Related codes sit mainly in the P07xx range, such as P0700 (transmission control system fault requested) and gear ratio codes P0730–P0736. Avoid heavy loads and long drives until the cause is known, because slipping quickly wears clutches and bands.

80Codes

3.1Average severity

23%High or critical

5%DIY-friendly

Severity distribution

Most viewed

P0700 Powertrain The transmission computer found a fault and asked for the check engine light – read the TCM… Moderate P0741 Powertrain The torque converter lockup clutch slips or won't engage when the computer commands it. Moderate U0073 Network A module saw so many errors on CAN bus A that it shut off its own transmitter. High U0100 Network Another module stopped hearing from the engine computer on the CAN network. High U0121 Network Other modules stopped receiving data from the ABS module, so ABS and stability control are off. Moderate P0105 Powertrain The PCM lost a usable signal from the manifold pressure sensor: dropouts, noise or values it… Moderate

All codes (70)

All Severity 3+ Severity 4+

C0055 Chassis The ABS module lost the combined rear-axle speed signal used on many GM trucks, vans and SUVs. Moderate P0105 Powertrain The PCM lost a usable signal from the manifold pressure sensor: dropouts, noise or values it… Moderate P0107 Powertrain The MAP signal has fallen to almost zero volts, usually from a lost 5-volt reference or an open… Moderate P0120 Powertrain The throttle position signal dropped out or glitched, so the PCM no longer trusts the throttle… Moderate P0123 Powertrain The throttle position signal is stuck near 5 volts, so the PCM sees wide open throttle even… Moderate P0218 Powertrain The transmission fluid got hotter than the computer allows, from heavy load, low fluid… High P0219 Powertrain The engine was spun faster than its maximum allowed rpm, usually by a missed shift or wheelspin. Moderate P0500 Powertrain The engine computer lost its vehicle speed signal – speedometer, shifting and cruise control… Moderate P0560 Powertrain The engine computer saw its supply voltage missing or out of range – check fuses and feeds… Moderate P0600 Powertrain The engine computer lost a dedicated data link to another module, most often the transmission… Moderate P0700 Powertrain The transmission computer found a fault and asked for the check engine light – read the TCM… Moderate P0705 Powertrain The computer can't make sense of the gear selector position signal – P, R, N, D may be misread. Moderate P0706 Powertrain The range sensor works electrically, but its reading doesn't match where the lever and gears… Moderate P0711 Powertrain The fluid temperature reading doesn't behave like real fluid – it warms too slowly, too fast… Moderate P0712 Powertrain The fluid temperature signal voltage is too low, so the computer thinks the fluid is extremely… Moderate P0715 Powertrain The transmission computer has lost a reliable input-shaft speed signal, so shifts get harsh… Moderate P0716 Powertrain The input speed signal is there but erratic or illogical – dropouts, spikes or values that… Moderate P0717 Powertrain The input speed sensor reports zero while the engine runs and the car moves – the signal… Moderate P0720 Powertrain Electrical fault in the output shaft speed signal – shift timing and sometimes the speedometer… Moderate P0722 Powertrain The output speed sensor sends nothing while the car moves – shifting and often the speedometer… Moderate P0730 Powertrain The transmission computer sees input and output shaft speeds that don't fit the gear it… High P0731 Powertrain While in first gear, the transmission's input and output speeds don't match the first-gear… Moderate P0732 Powertrain Second gear isn't holding: the input-to-output speed ratio in 2nd is outside the expected range. Moderate P0733 Powertrain Third gear slips: input shaft speed doesn't match output speed times the 3rd-gear ratio. Moderate P0734 Powertrain Fourth gear (overdrive on four-speed units) doesn't hold the expected input-to-output speed… Moderate P0735 Powertrain Fifth gear slips or isn't fully applied; the TCM measures a ratio that doesn't fit 5th. Moderate P0741 Powertrain The torque converter lockup clutch slips or won't engage when the computer commands it. Moderate P0742 Powertrain The converter lockup clutch stays applied when it should be released, which can stall… High P0744 Powertrain Lockup control drops in and out: an intermittent TCC circuit, or on some makes a lockup… Moderate P0746 Powertrain Solenoid A doesn't control pressure as commanded: harsh or soft shifts, or limp mode. Moderate

Symptoms

Check engine light on 558 Loss of power 214 Rough idle 184 Limp mode 165 Poor fuel economy 146 Engine stalling 133 Car won't start 123 ABS / traction light on 65 Fuel smell 34 Check engine light flashing 22