P1955 on Chevrolet
Transmission Fluid Pressure Relief Valve Performance
P1955 on Chevrolet vehicles indicates transmission fluid pressure relief valve performance. Au7o has documented this code across 1 Chevrolet model — most commonly on Corvette. Set in the Transmission Control Module when the commanded state of the transmission fluid pressure relief valve does not produce the expected hydraulic pressure response. On the C8 Corvette E-Ray's dual-clutch transmission, GM attributes this to auxiliary pump cavitation caused by a restricted transmission pan fluid filter: the starved pump cannot maintain pressure, so the TCM sees the relief valve circuit as underperforming. It typically sets alongside P0867 (Transmission Fluid Pressure Performance). GM explicitly directs technicians to replace the transmission pan fluid filter and to attempt no other repair for these codes. Typical repair costs on Chevrolet range from $350 to $900, depending on the specific model and root cause.
Common Causes of P1955
- •Restricted or clogged transmission pan fluid filter causing auxiliary pump cavitation (GM's stated cause on 2024-2026 Corvette E-Ray)
- •Low transmission fluid level or aerated fluid
- •Auxiliary/electric transmission fluid pump performance degradation
- •Pressure relief valve or valve body solenoid sticking
- •Debris circulating in the transmission hydraulic circuit
P1955 on Chevrolet by Model
Chevrolet Corvette(1 issue)
- E-Ray DCT Auxiliary Pump Cavitation - Service Transmission Message and DTCs P1955/P08672024-2026
On the E-Ray only, the 8-speed dual-clutch transmission carries an auxiliary fluid pump so the gearbox stays pressurized while the car is moving on electric power alone in Stealth or Shuttle mode. GM published Bulletin #25-NA-278 for 2024-2026 Corvette E-Ray models that display a Service Transmission message in the Driver Information Center along with an illuminated Check Engine MIL, with DTC P1955 (Transmission Fluid Pressure Relief Valve Performance) and/or P0867 (Transmission Fluid Pressure Performance) stored in the TCM. GM identifies the cause as auxiliary pump cavitation traced to the transmission pan fluid filter. This condition is specific to the hybrid E-Ray driveline and does not apply to the Stingray, Z06 or ZR1, which have no electric-only drive mode and no auxiliary pump duty cycle of this kind.
Looking for P1955 on a different make?
View P1955 across all makes →Frequently Asked Questions
What does P1955 mean on Chevrolet?▼
P1955 stands for "Transmission Fluid Pressure Relief Valve Performance." Set in the Transmission Control Module when the commanded state of the transmission fluid pressure relief valve does not produce the expected hydraulic pressure response. On the C8 Corvette E-Ray's dual-clutch transmission, GM attributes this to auxiliary pump cavitation caused by a restricted transmission pan fluid filter: the starved pump cannot maintain pressure, so the TCM sees the relief valve circuit as underperforming. It typically sets alongside P0867 (Transmission Fluid Pressure Performance). GM explicitly directs technicians to replace the transmission pan fluid filter and to attempt no other repair for these codes. On Chevrolet specifically, this code is documented across 1 model.
What causes P1955 on Chevrolet vehicles?▼
Common causes on Chevrolet: Restricted or clogged transmission pan fluid filter causing auxiliary pump cavitation (GM's stated cause on 2024-2026 Corvette E-Ray), Low transmission fluid level or aerated fluid, Auxiliary/electric transmission fluid pump performance degradation, Pressure relief valve or valve body solenoid sticking, Debris circulating in the transmission hydraulic circuit. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P1955 on a Chevrolet?▼
Repair costs on Chevrolet range from $350 to $900, depending on the specific model and root cause.
Which Chevrolet models have P1955 documented?▼
Au7o has documented P1955 on 1 Chevrolet model: Corvette.