By iCarsoft Official Store Technical Team, Automotive Diagnostics Editors · Updated September 10, 2026 · Technical sources checked
Quick Answer
The P0790 code means normal/performance switch circuit. It does not prove a pressure solenoid has failed, a clutch is slipping, or the complete transmission requires replacement. Save the scan, identify the exact architecture, and test the physical and electrical paths before selecting a repair.
What Does the P0790 Code Mean?
The P0790 code means Normal/Performance Switch Circuit. It names a monitored result, not a guaranteed failed part. The reporting module, suffix and companion faults determine the relevant test branch.
The normal/performance switch communicates a driver mode request in an OEM-defined arrangement. Its location, naming, wiring and receiving module vary. Do not assume that every Sport button is this input or that the switch directly carries a transmission solenoid's power. Trace the exact request path before choosing electrical test points.
Read selected mode and actual operating strategy as different data points. If an enhanced PID exposes the request, record whether it changes consistently with the driver's action. If the PID is unavailable, that is a coverage limitation rather than proof of a circuit fault. Use the OEM diagnostic path rather than guessing from the dashboard alone.
Autel and Snap-on manufacturer-published DTC lists identify P0790 as Normal/Performance Switch Circuit. Those lists establish the generic fault identity; they do not document a specific vehicle's switch locations, signal levels, communication architecture or fallback strategy. This article does not claim a verified model-specific P0790 repair case.
A mode button, its indicator and the mode received by the transmission controller are separate observations. A working lamp does not prove the controller received a valid request, and an unchanged shift feel does not prove a dead switch. The operating conditions may not call for a noticeable difference even when a mode request is accepted.
Separate P0790 from adjacent fault families
| Code | General description | Key distinction |
|---|---|---|
| P0790 | Normal/performance switch circuit | Driver-mode input circuit; not a pressure-control solenoid code. |
| P0705 | Transmission range sensor circuit | Selected range input, distinct from normal/performance mode. |
| P078F | Transmission mode switch C circuit | Different mode-switch classification; identify the OEM assignment. |
| P0791 | Intermediate shaft speed sensor A circuit | Speed input, not a normal/performance selector fault. |
Record the complete P0790 description. The suffix, reporting module and companion faults can change the diagnostic path. Use the manufacturer's full wording and test procedure for the exact vehicle.
P0790 Symptoms and Likely Causes
P0790 symptoms depend on fault status and the fallback strategy. Record what the driver and modules reported. A symptom list is not a parts list.
Record which button or selector was used and what the display showed. Confirm that it is the input associated with P0790.
An inconsistent indication needs comparison with module data. A lamp, switch and received request may fail in different ways.
Preserve all TCM records. A mode-circuit fault does not by itself establish a particular fallback gear or hydraulic pressure.
Driving conditions can mask the effect of a valid mode request. Do not diagnose a circuit solely from how a short drive feels.
Practical cause-checking order
- Input identification: The wrong switch or signal may be inspected if the generic label is interpreted as any Sport or drive-mode control. Use the wiring diagram and exact OEM wording.
- Switch assembly: A switch contact or integrated selector assembly may fail to provide the specified request. Test its prescribed states instead of assuming that illumination proves the contacts work.
- Connector and harness: Loose terminals, spills, corrosion or trim-related pinching can interrupt the path. Inspect safely and preserve evidence before cleaning or moving connectors.
- Supply or signal path: A supply, ground or signal defect may prevent a valid input from reaching the module. The permitted tests depend on whether the circuit is discrete or integrated with other electronics.
- Receiving module or configuration: Configuration or an internal input fault can remain after external checks. Confirm applicable service information before replacing a module or resetting transmission adaptations.
Did P0790 appear after recent console, selector, switch-panel, wiring or battery service? Recheck the documented connections, parts and setup steps affected by that work. Record battery and software history; a post-repair code does not prove the new part is defective.
How Serious Is P0790, and Can You Drive?
Follow the owner's manual and arrange diagnosis. Stop for unpredictable engagement, loss of drive, severe shifting, overheating or unintended movement. A mode-switch code alone does not establish those symptoms, but it also cannot guarantee that continued driving is safe when they occur.
Record temperature, load, speed, start state and recent service. Do not reproduce a severe symptom on public roads; another warning can make the situation more urgent.
Stop and arrange a tow if engagement becomes unpredictable, drive is lost, shifting becomes severe, a temperature warning appears or the vehicle moves unexpectedly.
Secure the vehicle before operating selectors or switches. Do not bypass a range interlock or jumper a mode input to force a particular state. Console and steering-area access may involve other safety equipment; follow the OEM isolation and trim-removal procedure rather than probing unidentified connectors.
How to Diagnose P0790 in the Right Order
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Save the mode-selection complaint and full scan
Read the transmission and related modules where supported and save P0790 status, full wording and available freeze frame. Record what the driver selected, what the indicator showed and whether the vehicle behaved abnormally. Preserve companion range, supply and communication records before clearing anything; they may describe a separate fault rather than a consequence of the mode switch.
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Identify the exact switch and receiving module
Use VIN-specific information to identify the normal/performance input, its physical control and receiving module. Determine how the request travels through the installed system and locate the correct circuit diagram. Do not assume that a generic Sport button, manual-shift gate or transmission range sensor is the same component just because it changes vehicle behavior.
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Compare selection, indication and received request
With the vehicle safely secured and the prescribed operating conditions met, compare driver action with indicator behavior and any supported request PID. Record whether each selection registers consistently. An unchanged shift feel is not sufficient evidence of an electrical fault. If the PID is unavailable, continue with the OEM test method rather than interpreting missing data as failure.
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Inspect the affected switch and harness safely
Follow the specified shutdown and access procedure to inspect the switch, connectors and reachable harness. Look for liquid contamination, loose terminals, pinched wiring and disturbance from console or selector work. Avoid probing unidentified safety-system connectors. Photograph the original condition and preserve the sequence of findings instead of disconnecting every nearby assembly.
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Test the documented input states without bypassing
Use the manufacturer's state table and suitable instruments to test the relevant contacts, supply, ground or signal path. Isolate electronics as required and use approved access adapters. Do not add a jumper, apply battery voltage to an input or force a networked mode request. A resistance or voltage value from another switch design is not a valid specification.
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Verify the repaired request and related functions
Repair the confirmed switch, terminal, harness or receiving-input fault and perform any required configuration for replaced parts. Restore trim without trapping wiring. Verify that each intended mode request is received under the correct conditions and check related functions. Clear only erasable faults after repair, then rescan; do not reset unrelated transmission adaptations as a substitute for verification.
Specifications are vehicle-specific. Use the exact VIN specifications, approved test points and required operating state. No generic value or drive cycle can replace the applicable procedure. Manufacturer examples here do not establish specifications for other applications.
P0790 Repairs and Typical Costs
The correct P0790 repair follows the failed test. Wiring, a physical repair, a proven component, software and controller work are different outcomes. Do not replace an assembly from the generic code alone.
Recheck installation and required setup after repair. After repairing a switch or harness, restore trim and connector retention without trapping wiring. Confirm any required configuration for a replaced assembly before purchase or installation. A replacement selector or switch panel may include several functions; verify all affected functions without changing unrelated driver preferences or adaptations.
| Possible path | Current US estimate |
|---|---|
| Repair a verified switch-panel connector or harness defect | VIN-specific quote |
| Replace a switch or selector assembly that fails its state test | VIN-specific quote |
| Restore a demonstrated supply, ground or signal-path fault | VIN-specific quote |
| Correct a confirmed receiving-module or configuration problem | VIN-specific quote |
These are alternative repair paths, not prices to add together. Request a VIN-specific quote separating diagnosis, parts, labor, fluids, taxes, required setup and verification. Ask which failed test supports the proposed repair and whether warranty coverage applies.
Using iCarsoft CR MAX BT for P0790
On a supported vehicle, iCarsoft CR MAX BT can retrieve accessible module faults, save available freeze frame, display ECU-provided live data and create a diagnostic report. For P0790, preserve the original evidence and compare related modules before clearing an erasable record.
Preserve the normal/performance mode-switch circuit evidence
iCarsoft CR MAX BT
Review supported codes and relevant live data together. Confirm the exact VIN, controller access, PIDs and any requested active test with iCarsoft before purchase; generic product capabilities do not guarantee a P0790-specific function.
Check current CR MAX BT price and availabilityCheck CR MAX BT compatibility by VINThe official product page describes wireless all-system diagnostics and supported bidirectional controls; available live data, test coverage and coding functions vary with the vehicle, ECU and software. Confirm the requested function by VIN before purchase. Follow OEM prerequisites and stop for abnormal operation.
Know the measurement boundary. Scan data describes ECU-provided information; it does not directly prove the physical condition of the normal/performance mode-switch circuit. Use approved electrical test tools and the OEM switch-state or signal documentation where required, and compare reported values with the relevant measured evidence.
Verify the P0790 Repair
After repair, verify connectors, harness clearance, setup and controller supply. Save post-repair findings, then clear only erasable records through the approved procedure. Battery disconnection is not a repair.
Run the manufacturer's applicable verification conditions in a safe workshop or route. Compare the original operating state with current data for the normal/performance mode-switch circuit, and check current and pending faults in related modules. One clean start or idle period does not prove that every conditional monitor has completed.
If P0790 returns, compare its suffix, status, failure order and operating conditions with the saved baseline before replacing another part. Revisit the failed branch and inspect anything disturbed. Keep mechanical repair, monitor completion, readiness and local inspection eligibility as separate outcomes.
A permanent P0790 can remain immediately after a successful repair. If stored as a permanent DTC, it cannot be erased by a scan tool or battery disconnect. The vehicle must complete the applicable successful monitor verification.
Related Normal/Performance Mode-Switch Circuit Code Guides
P0790 Frequently Asked Questions
Does the P0790 code mean the named component is bad?
No. P0790 describes normal/performance switch circuit, not a confirmed part. It also does not prove a pressure solenoid has failed, a clutch is slipping, or the complete transmission requires replacement. Use the OEM test sequence to distinguish the circuit, load and controller before replacing parts.
What should I check first for P0790?
Save every module's codes and freeze frame before clearing. Confirm the full definition, suffix and VIN architecture. Then inspect recent console, selector, switch-panel, wiring or battery service, connectors and shared supplies. Those facts determine whether the next test needs approved electrical test tools and the OEM switch-state or signal documentation or a manufacturer-specific functional procedure.
Can I drive with the P0790 code?
Follow the owner's manual and arrange diagnosis. Stop for unpredictable engagement, loss of drive, severe shifting, overheating or unintended movement. A mode-switch code alone does not establish those symptoms, but it also cannot guarantee that continued driving is safe when they occur.
Why did P0790 return after a part was replaced?
The replacement may not have repaired the input wire, connector, supply or receiving-module fault. The tested button may also have been unrelated to the OEM-defined normal/performance input. Compare the actual mode request with the original event, verify part identity and setup, and avoid substituting transmission mechanical work for an unresolved selector-circuit problem.
What should a P0790 repair estimate include?
Ask for the failed-test evidence and a VIN-specific breakdown of diagnosis, parts, labor, taxes, required setup and verification. A code alone cannot establish the repair price.
Can CR MAX BT diagnose and clear P0790?
On a supported vehicle, CR MAX BT can organize available faults, freeze frame, live data and reports, and can clear erasable records after repair. Confirm exact ECU coverage. It cannot force-clear a permanent DTC or replace physical measurements for the normal/performance mode-switch circuit.
The iCarsoft Official Store Technical Team maintains the store's fault-code library. This guide organizes published manufacturer evidence and verified product information; it does not document a hands-on test of a particular vehicle or claim an individual engineer's review.
Technical and cost references
- Autel Manufacturer DTC Reference List. P0790 normal/performance switch identity and adjacent mode/speed classifications; no vehicle-specific electrical limits.
- Snap-on Diagnostic Trouble Codes List. Independent manufacturer reference for the generic P0790 description only.
- California Bureau of Automotive Repair — On-Board Diagnostic Test Reference. Permanent DTCs are removed by the vehicle after applicable verification, not by a scan-tool erase command.
Product information: Official iCarsoft CR MAX BT page.
Editorial note: General diagnostic education, not a substitute for the owner's manual, current VIN-specific service information or professional inspection. Test limits, procedures, coverage and costs vary. Related articles provide context; apply only the specifications and repair procedures that match the vehicle. No universal failure rate, repair price or outcome is implied.
