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 (80)

All Severity 3+ Severity 4+

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 P0740 Powertrain The computer found an open or faulty circuit to the torque converter clutch solenoid, so lockup… Low 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 P0743 Powertrain The TCC solenoid circuit shows an electrical fault such as a short, overcurrent or out-of-range… Low 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 P0748 Powertrain The TCM detected an electrical fault (open, short or wrong current) in pressure control… Moderate P0750 Powertrain The transmission computer sees a fault in shift solenoid A or its circuit and can't use it… Moderate P0751 Powertrain Solenoid A is wired fine but its valve isn't doing its job, so gears are missing – often stuck… High P0753 Powertrain The control circuit for shift solenoid A reads open, shorted or out of range – an electrical… Moderate P0755 Powertrain The TCM detects an electrical problem with shift solenoid B, the second on/off shift valve. Moderate P0756 Powertrain Solenoid B isn't moving fluid the way the TCM expects – the car may pull away in 3rd or 4th. High P0760 Powertrain A fault in shift solenoid C's circuit – usually means lost overdrive or upper gears, or limp… Moderate P0770 Powertrain Solenoid E in a five- or six-speed automatic isn't working as commanded: electrical fault… Moderate P0773 Powertrain The transmission computer found an open, short or wrong current in the solenoid E circuit… Moderate P0776 Powertrain Pressure control solenoid B isn't delivering the pressure the TCM asks for – harsh or slipping… Moderate P0780 Powertrain A gear change didn't complete the way the TCM expected, but it can't pin the fault to one part. Moderate P0781 Powertrain The upshift from 1st to 2nd is too slow, slips or never completes properly. Moderate P07A3 Ford · Powertrain The PowerShift's odd-gear clutch isn't letting go when the TCM commands it open, so the car… High P0841 Powertrain Pressure sensor or switch A reports a value that doesn't fit the gear or pressure the TCM… Moderate P0851 Powertrain The engine computer sees the park/neutral input stuck at low voltage, often from a short… Low P0868 Powertrain Measured transmission line pressure is below what the TCM commanded – clutches can slip… High P0884 Powertrain The transmission computer's power supply dropped out briefly – usually a battery, ground… Moderate P0887 Powertrain The circuit that switches the transmission power relay reads high voltage when it shouldn't. Moderate P0894 Powertrain The transmission computer measured slip inside the gearbox that shouldn't be there. Clutches… High P090C Ford · Powertrain The PowerShift TCM sees a low signal on the motor that works clutch B, the even-gear… Moderate P1529 Kia · Powertrain Your Kia's transmission computer found a fault and asked the engine computer to light the check… Moderate P1633 Ford · Powertrain Ford's PCM lost its constant battery feed, so the memory holding learned fuel, idle and shift… Low

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