P2797 — Auxiliary Transmission Fluid Pump Performance

P2797 — Auxiliary Transmission Fluid Pump Performance. A fault in the automatic transmission control. Short, gentle driving to a shop is usually possible. Typical causes: faulty transmission speed sensor, wiring or connector faults in the valve body harness, failed shift or pressure control solenoid.

powertrain (engine/transmission)

Is it safe to drive?

Drive with caution Drive only if the transmission still shifts predictably, and avoid highway speeds. Driving with slipping or limp mode accelerates internal wear — every kilometre can add to the final repair bill.

How to diagnose with an OBD scanner

  1. Read the code and freeze frame Connect an OBD2 scanner, confirm P2797 is stored, and save the freeze frame data — it shows engine conditions when the fault was detected.
  2. Check for companion codes and TSBs Related codes often reveal the real root cause. Also check manufacturer technical service bulletins (TSB) for your make and model — many P0xxx issues have factory fixes or software updates. Search by VIN on the manufacturer site or nhtsa.gov.
  3. Inspect wiring and connectors Visually inspect the wiring harness and connectors related to the automatic transmission control for damage, corrosion, chafing or poor contact.
  4. Subsystem check Check transmission fluid level and condition — dark, burnt fluid points to internal wear.
  5. Subsystem check Read transmission-specific codes and live data (solenoid states, input/output speed) with a capable scanner.
  6. Verify the repair Clear the code, complete a full drive cycle including the conditions from the freeze frame, and confirm P2797 does not return.

Approximate repair cost

Repair cost depends on which component actually failed. Typical scenarios for P2797 (parts and labor, USD, independent shop rates): Replace a shift solenoid: $300–$800; Valve body repair or replacement: $700–$1,500; Transmission rebuild or replacement: $2,500–$5,500; Transmission fluid service: $150–$350. Overall, fixing P2797 usually costs between $150 and $5,500. An accurate diagnosis before buying parts saves money — the most expensive scenario is rarely the first one to check.

Common questions

What does OBD2 code P2797 mean?

P2797 — Auxiliary Transmission Fluid Pump Performance. A fault in the automatic transmission control. Short, gentle driving to a shop is usually possible. Typical causes: faulty transmission speed sensor, wiring or connector faults in the valve body harness, failed shift or pressure control solenoid.

How much does it cost to fix P2797?

Replace a shift solenoid — $300–$800; Valve body repair or replacement — $700–$1,500; Transmission rebuild or replacement — $2,500–$5,500; Transmission fluid service — $150–$350. Exact cost depends on the root cause, your vehicle and local labor rates — a proper diagnosis is the cheapest first step.

Will P2797 clear itself?

Sometimes P2797 clears after a few drive cycles if the fault was intermittent — for example a loose connector or a tank of bad fuel. The underlying cause usually remains, so the code tends to return. Clear it once; if it comes back, diagnose rather than erase it repeatedly.

How do I diagnose P2797 myself?

Start with a scan: confirm P2797, save the freeze frame and note any companion codes. Then inspect the wiring and connectors related to the automatic transmission control, and verify the suspect component against live data before buying parts.

What is the most common cause of P2797?

The most common causes are: faulty transmission speed sensor, wiring or connector faults in the valve body harness, failed shift or pressure control solenoid.

What does P2797 mean?

Seeing P2797 on your scanner? The control unit has caught the automatic transmission control operating outside its calibrated window. The formal description is “Auxiliary Transmission Fluid Pump Performance”, and the code is grouped under powertrain (engine/transmission) faults.

This code does not appear from a single bad reading: the module must see the fault condition repeat under defined operating conditions before it turns on the warning light. The freeze frame captured with P2797 — engine load, rpm, temperature, speed — tells you exactly when the problem occurs, so reproduce those conditions when testing.

Common symptoms of P2797

  • slipping between gears
  • no movement in severe cases
  • shuddering at highway speed
  • transmission stuck in one gear (limp mode)
  • harsh or delayed shifting

What causes P2797?

  • valve body wear
  • wiring or connector faults in the valve body harness
  • failed shift or pressure control solenoid
  • low or degraded transmission fluid

How to diagnose P2797

  1. Connect an OBD2 scanner, confirm P2797 is stored, and save the freeze frame data — it shows engine conditions when the fault was detected.
  2. Related codes often reveal the real root cause. Also check manufacturer technical service bulletins (TSB) for your make and model — many P0xxx issues have factory fixes or software updates. Search by VIN on the manufacturer site or nhtsa.gov.
  3. Visually inspect the wiring harness and connectors related to the automatic transmission control for damage, corrosion, chafing or poor contact.
  4. Check transmission fluid level and condition — dark, burnt fluid points to internal wear.
  5. Read transmission-specific codes and live data (solenoid states, input/output speed) with a capable scanner.
  6. Clear the code, complete a full drive cycle including the conditions from the freeze frame, and confirm P2797 does not return.

How to fix P2797

Start with the cheapest and most common causes before replacing expensive parts:

  • Replace a shift solenoid — $300–$800
  • Valve body repair or replacement — $700–$1,500
  • Transmission rebuild or replacement — $2,500–$5,500
  • Transmission fluid service — $150–$350

How much does it cost to fix P2797?

Repair cost depends on which component actually failed. Typical scenarios for P2797 (parts and labor, USD, independent shop rates):

  • Replace a shift solenoid: $300–$800
  • Valve body repair or replacement: $700–$1,500
  • Transmission rebuild or replacement: $2,500–$5,500
  • Transmission fluid service: $150–$350

Overall, fixing P2797 usually costs between $150 and $5,500. An accurate diagnosis before buying parts saves money — the most expensive scenario is rarely the first one to check.

Can you drive with P2797?

Drive only if the transmission still shifts predictably, and avoid highway speeds. Driving with slipping or limp mode accelerates internal wear — every kilometre can add to the final repair bill.

Related OBD2 codes