P0748 on Toyota
Pressure Control Solenoid "A" Electrical
P0748 on Toyota vehicles indicates pressure control solenoid "a" electrical. Au7o has documented this code across 1 Toyota model — most commonly on 4Runner. P0748 is a generic powertrain code meaning the transmission control module has detected an electrical fault — voltage or resistance out of the expected range — in the circuit for pressure control solenoid "A". This solenoid regulates hydraulic line pressure inside an automatic transmission, adjusting how firmly the clutches and bands apply based on speed, load, and throttle position. When the computer can't control the solenoid electrically, the transmission often defaults to maximum line pressure or limp mode, so you may feel harsh or erratic shifts, slipping, delayed engagement when shifting into Drive, or being locked into a single gear. Because it is an electrical-circuit code, the fault is usually in the solenoid itself or its wiring rather than a purely hydraulic problem, though contaminated fluid can damage the solenoid. Continuing to drive with slipping and overpressure shifts can overheat the transmission and lead to expensive internal damage, so this should be repaired promptly. Typical repair costs on Toyota range from $150 to $1,500, depending on the specific model and root cause.
Common Causes of P0748
- •Failed pressure control solenoid A (open or shorted solenoid windings)
- •Damaged, frayed, or shorted wiring in the solenoid circuit, including the transmission case connector
- •Corroded or loose electrical connectors at the transmission harness
- •Low, dirty, or contaminated transmission fluid degrading or sticking the solenoid
- •Clogged transmission filter or debris in the valve body hydraulic passages
- •Faulty transmission control module or PCM driver circuit (rare)
P0748 on Toyota by Model
Toyota 4Runner(1 issue)
- High-Mileage Harsh / Jerky Automatic Shifting from Valve-Body Pressure Issues2003-2024
On higher-mileage 4Runner automatics owners report harsh/abrupt shifts, jerky 3-2 downshifts, unstable RPM blips while coasting near 40 mph, and delayed engagement. The most common mechanical cause is valve-body pressure control wear - a sticking pressure-regulator or throttle valve, or a worn shift solenoid - which raises line pressure and slams the shifts, separate from the torque-converter shudder issue. RepairPal logs hundreds of reports of these trucks not shifting correctly at high mileage. Long-neglected, dark/burnt ATF accelerates it.
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View P0748 across all makes →Frequently Asked Questions
What does P0748 mean on Toyota?▼
P0748 stands for "Pressure Control Solenoid "A" Electrical." P0748 is a generic powertrain code meaning the transmission control module has detected an electrical fault — voltage or resistance out of the expected range — in the circuit for pressure control solenoid "A". This solenoid regulates hydraulic line pressure inside an automatic transmission, adjusting how firmly the clutches and bands apply based on speed, load, and throttle position. When the computer can't control the solenoid electrically, the transmission often defaults to maximum line pressure or limp mode, so you may feel harsh or erratic shifts, slipping, delayed engagement when shifting into Drive, or being locked into a single gear. Because it is an electrical-circuit code, the fault is usually in the solenoid itself or its wiring rather than a purely hydraulic problem, though contaminated fluid can damage the solenoid. Continuing to drive with slipping and overpressure shifts can overheat the transmission and lead to expensive internal damage, so this should be repaired promptly. On Toyota specifically, this code is documented across 1 model.
What causes P0748 on Toyota vehicles?▼
Common causes on Toyota: Failed pressure control solenoid A (open or shorted solenoid windings), Damaged, frayed, or shorted wiring in the solenoid circuit, including the transmission case connector, Corroded or loose electrical connectors at the transmission harness, Low, dirty, or contaminated transmission fluid degrading or sticking the solenoid, Clogged transmission filter or debris in the valve body hydraulic passages. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P0748 on a Toyota?▼
Repair costs on Toyota range from $150 to $1,500, depending on the specific model and root cause.
Which Toyota models have P0748 documented?▼
Au7o has documented P0748 on 1 Toyota model: 4Runner.