On this page
- The one-line answer
- How the JF015E sets a code
- Function codes versus electrical codes
- P0776
- P0840 / P0841 / P0846
- P0965 on the Chevrolet Spark
- The judder family
- P2857 / P2858 and the auxiliary gearbox
- P0715 / P1715 / P0720 / P0730
- The full code table
- What to send us with the code list
- Sources and frequently asked questions
Fault codes on this platform are a map, not a diagnosis. The same P0776 can come from a worn bore, a tired solenoid, degraded fluid or a cracked connector — and the same judder complaint can be a valve body, a belt, or a calibration issue that a software update addresses. This page separates the codes by what the control unit actually measured, because that is the only sane basis for deciding which part to order.
What this page gives you
- The monitor condition behind each headline code — what the TCM had to see before it stored it.
- Function versus electrical: why P0776 and P0965 are not the same fault, and why the distinction changes the repair.
- The judder family P17F0 / P17F1 / P17F2 / P17F4, and which of the four points at a new unit rather than a valve body.
- The auxiliary gearbox codes P2857 / P2858 — the ones Nissan's own bulletins treat as a replacement.
- A full code table with the first part to check against every code we see weekly.
01The one-line answer
If you only read one line: read the code, then ask what the control unit could have measured. If it measured a pressure difference (P0776) or reported a sensor range problem (P0841), the hydraulic side is in play and the valve body is the first part. If it measured a ratio error (P0730) or flagged a judder inspection step (P17F0/P17F1/P17F2/P17F4), the belt and pulleys are in play — and on P17F2/P17F4/P2857/P2858 the trade treats the answer as a replacement unit.
Everything below expands those two sentences into something you can act on.
02How the JF015E sets a code
The CVT7 hydraulic chain is short, and every headline code attaches to one link of it. Understand the chain and the code list stops being a list.
| Stage | What it does | What watches it | Codes that live here |
|---|---|---|---|
| Off-axis oil pump | Makes the line pressure everything else runs on | Indirectly, through pressure readings | P0841 / P0965 (symptom rather than cause) |
| Line pressure control solenoid | Sets the base pressure for the whole system | TCM command versus pressure result | P0746 |
| Secondary pressure solenoid | Clamps the belt — the single most critical value on a CVT | Target versus actual secondary pressure | P0776 · P0965 · P0966 · P0967 |
| Fluid pressure sensors | Report what the hydraulic circuit actually achieved | Sensor electrical range and plausibility | P0840 · P0841 · P0846 |
| Pulleys and steel belt | Transfer torque by friction at the cone faces | Ratio calculation from input and output speeds | P0730 · P17F0 · P17F1 |
| Torque converter lock-up clutch | Eliminates slip at cruising speed | Slip speed against command | P0740 · P0741 · P0744 · P1740 |
| Speed sensors | Give the TCM the data every other calculation depends on | Signal presence and plausibility | P0715 · P1715 · P0720 |
| Auxiliary gearbox (2-speed) | CVT7-specific launch and high-range clutches | Clutch pressure and judder detection | P2857 · P2858 · P17F4 |
03Function codes versus electrical codes
This distinction is the most useful thing on the page, and it is routinely missed. On the secondary pressure solenoid circuit alone there are four codes, and they do not mean the same thing.
| Code | Category | What it means | What it usually costs |
|---|---|---|---|
| P0776 | Function | Electrically the solenoid is fine, but the pressure it produced did not match the command | Hydraulic — valve body, worn bore, solenoid performance, fluid |
| P0965 | Electrical — range/performance | Control circuit for the same solenoid is outside the permitted range | Electrical or hydraulic — check connector and harness before condemning the body |
| P0966 | Electrical — short / low input | Solenoid circuit shorted or drawing below specification | Wiring, TCM connector, then the solenoid itself |
| P0967 | Electrical — open / high input | Open circuit or excessive resistance | Connector, harness, then the solenoid |
Manufacturer diagnostic procedure for P0776 explicitly directs the technician to first check whether P0966 or P0967 is also stored, and to follow the electrical path if it is — then to oscilloscope the solenoid output pattern at the control unit terminal before condemning the assembly. Source: published P0776 diagnostic function and probable-cause section (JATCO CVT service data, Mitsubishi technical information).
If the car arrives with P0965 and nothing else, check the TCM connector and harness before quoting a valve body. A cracked or corroded connector reproduces an internal electrical fault almost perfectly, and we have seen units replaced for a fault that lived in the plug. If P0965 is stored together with P0776 or P0841, treat it as a hydraulic case with an electrical echo.
04P0776: what the control unit actually measured
P0776 is not "the solenoid is broken". It is a performance calculation:
| Element | Published criterion |
|---|---|
| Method | The control unit compares the target secondary pressure with the actual secondary pressure |
| Engine state | Engine running |
| Selector position | Any position other than P or N |
| Fluid temperature | Above approximately −20 °C |
| Threshold | A gap of 1.2 MPa or more between target and actual, sustained for 10 seconds |
| Probable causes | Valve body assembly — faulty secondary pressure solenoid valve; or the CVT assembly itself |
Figures as published in the manufacturer diagnostic function for P0776 on this CVT platform. The same page notes that if the code only appears occasionally after clearing, it should be treated as an intermittent fault rather than a replacement trigger.
Two practical consequences follow. First, a code that appears only under specific temperature or load conditions is a performance problem, and performance problems are what remanufactured valve bodies exist for. Second, when the gap is caused by the belt already slipping rather than by the hydraulics, replacing the valve body buys you weeks, not years — which is why the fluid sample matters as much as the code.
JF015E valve body — check availability →
05P0840 / P0841 / P0846: the pressure sensor family
These three describe the sensors that report hydraulic pressure back to the control unit, and they are the codes most often found sitting alongside P0776 — which is also what makes them easy to misread.
| Code | Scanner wording | What it is telling you |
|---|---|---|
| P0840 | Transmission fluid pressure sensor / switch A — circuit | An electrical problem with the sensor circuit itself |
| P0841 | Transmission fluid pressure sensor / switch A — range / performance | The sensor is working, but the pressure it reports is not plausible for the commanded state |
| P0846 | Transmission fluid pressure sensor / switch B — range / performance | The same plausibility failure on the second pressure circuit |
When P0841 accompanies P0776, the two are describing the same event from two directions: the TCM sees a pressure it cannot explain. That is a hydraulic inspection, not a sensor replacement.
06P0965 on the Chevrolet Spark: a documented case
The Spark is the clearest worked example of this code in the field, and it is worth knowing even if you never see one, because it shows how a code becomes a policy.
| Fact | Detail |
|---|---|
| Vehicle | 2013–2015 Chevrolet Spark (and GM Daewoo equivalents), 1.0L / 1.2L |
| Transmission | JATCO CVT7 — JF015E / RE0F11A |
| Code | P0965 — pressure control solenoid B control circuit range / performance |
| Most common outcome | Valve body or solenoid replacement; sometimes the whole transmission if debris has reached the pulleys |
| Manufacturer response | GM Special Coverage N192271110 extended coverage on the transmission for this failure |
| The trap | The TCM connector is known to crack during service on these cars and can mimic an internal fault |
Before quoting parts for a Spark with P0965, the owner may still be inside the manufacturer's special coverage window — check by VIN first. Source: GM special coverage programme N192271110 as reported in aftermarket service documentation for this platform.
07The judder family: P17F0, P17F1, P17F2, P17F4
These codes are not component faults. They are inspection instructions, and each one narrows where to look next.
| Code | Inspection it calls for | Practical reading |
|---|---|---|
| P17F0 | CVT judder — transmission inspection | The control unit detected slip behaviour. Valve body first; belt and pulleys if the fluid is contaminated |
| P17F1 | CVT judder — control valve inspection | Points at the hydraulic control path. Software level and valve body come before anything else |
| P17F2 | CVT judder — torque converter inspection | On the models where this applies, the trade literature treats the outcome as unit replacement |
| P17F4 | Auxiliary gearbox clutch judder | The CVT7-specific two-speed gearbox clutches. Commonly treated as unit replacement |
Judder detection thresholds were revised by manufacturer service bulletins (including NTB20-060A and its revisions, and the diagnostic-path bulletin NTB22-021 covering P0746, P0776, P0841, P0965, P17F0 and P17F1). A software update changes how early the unit reports judder; it does not restore a polished pulley face. Always verify the software level before condemning hardware, and never treat a reflash as a repair.
P17F0 or P17F1 with a clean fluid sample and no metal dust: the valve body is the first part to replace. The same codes with glitter in the fluid: plan on the pulley set and push belt as well, or a complete assembly — because the debris that produced the judder is still circulating through the new hydraulics.
08P2857 / P2858 and the auxiliary gearbox
The CVT7's two-speed auxiliary gearbox is what makes this unit different from every other CVT in the JATCO range — and it has its own codes. When they appear, the manufacturer's diagnostic path is short, and it does not end at a valve body.
| Code | Monitors | Where the path leads |
|---|---|---|
| P2857 | Clutch A pressure in the auxiliary gearbox | Clutch and planetary hardware inside the unit |
| P2858 | Clutch B pressure in the auxiliary gearbox | Same — and manufacturer bulletins for the affected models call for unit replacement |
If you are seeing these together with P17F4, the auxiliary gearbox is the story, not the valve body. A complete JF015E assembly is usually the honest answer; say so up front rather than selling a valve body into a clutch problem.
09P0715 / P1715 / P0720 / P0730: the speed and ratio codes
These four behave differently from everything above, and they are where rebuilders most often chase the wrong part.
| Code | Monitors | First thing to check |
|---|---|---|
| P0715 | Input / turbine speed sensor circuit | Sensor, connector and harness routing — especially immediately after a rebuild |
| P1715 | Input pulley speed sensor (Nissan terminology) | Often stored together with P0776 or P0841; treat as part of the same CVT diagnosis rather than a separate fault |
| P0720 | Output speed sensor circuit | Sensor and wiring; if the speedometer is also wrong, start at the sensor |
| P0730 | Incorrect transmission ratio detected | The belt and pulley faces. This is the code that says "mechanical", not "hydraulic" |
A ratio code on a freshly rebuilt unit is usually a speed-signal problem, not a mechanical one — check sensor installation depth, connector seating and harness routing before reopening the case. A ratio code on a high-mileage untouched unit, with metal dust in the pan, is the belt.
10The full code table
Everything we see weekly on this platform, with the first part worth checking on each path.
| Code | Scanner wording (short) | Group | First part to check |
|---|---|---|---|
| P0740 | Torque converter clutch circuit | Lock-up | Fluid and lock-up control in the valve body |
| P0741 | Torque converter clutch — stuck off | Lock-up | Valve body; converter if the complaint persists after repair |
| P0744 | Torque converter clutch — intermittent | Lock-up | Fluid condition, then valve body |
| P0746 | Pressure control solenoid A — performance | Hydraulic function | Valve body |
| P0776 | Pressure control solenoid B — performance | Hydraulic function | Valve body |
| P0840 | Fluid pressure sensor / switch A — circuit | Sensor | Harness and connector, then the unit |
| P0841 | Fluid pressure sensor / switch A — range | Sensor plausibility | Hydraulic inspection — usually paired with P0776 |
| P0846 | Fluid pressure sensor / switch B — range | Sensor plausibility | Hydraulic inspection |
| P0965 | Pressure control solenoid B — circuit range / performance | Electrical + hydraulic | Connector and harness first, then the solenoid kit |
| P0966 | Pressure control solenoid B — low input | Electrical | Wiring, TCM connector, solenoid |
| P0967 | Pressure control solenoid B — high input | Electrical | Wiring, TCM connector, solenoid |
| P0715 | Input / turbine speed sensor | Sensor | Speed sensor and harness |
| P1715 | Input pulley speed sensor | Sensor | Same as above; treat as part of the CVT diagnosis |
| P0720 | Output speed sensor | Sensor | Speed sensor and wiring |
| P0730 | Incorrect ratio detected | Mechanical | Pulley set and push belt |
| P17F0 | CVT judder — transmission inspection | Judder | Valve body, then belt and pulleys |
| P17F1 | CVT judder — control valve inspection | Judder | Software level, then valve body |
| P17F2 | CVT judder — torque converter inspection | Judder | Unit-level outcome on the affected models |
| P17F4 | Auxiliary gearbox clutch judder | Auxiliary gearbox | Assembly — not a valve body |
| P2857 | Auxiliary gearbox clutch A pressure | Auxiliary gearbox | Assembly |
| P2858 | Auxiliary gearbox clutch B pressure | Auxiliary gearbox | Assembly |
| P1740 | Lock-up select solenoid | Lock-up | Valve body and solenoid |
| P0705 | Park / neutral position switch | Electrical | Switch adjustment, then the switch |
| P0850 | Park / neutral position switch input | Electrical | Same as above |
Code wording follows generic OBD-II scan-tool text with manufacturer terminology where it differs (for example P1715, used for the input pulley speed sensor). Code sets vary by model year, market calibration and control unit software level; the full list for your unit is on the manufacturer's side, and the final diagnosis belongs to the workshop in front of the car. What we add is the parts half of the decision.
11What to send us with the code list
Five items turn a code list into a firm part confirmation, and they take ten minutes to gather.
| Item | Why we need it |
|---|---|
| Full stored code list — current and pending, not just the first one | P0965 alone is an electrical case; P0965 with P0776 is a hydraulic one |
| Transmission code from the housing | Confirms RE0F11A versus the wide-ratio RE0F11B variant |
| VIN | Market calibration, which changes the valve body part number |
| Photo of the original valve body, solenoid side | Solenoid count, cap type and the OE number on the body |
| Fluid condition and mileage | Decides whether a valve body is a repair or the first half of one |
12Sources and frequently asked questions
Monitor conditions and probable causes on this page follow published manufacturer diagnostic functions for this CVT platform (including the P0776 diagnostic function and its 1.2 MPa / 10-second criterion, and the P0966 / P0967 electrical branches). Judder-code behaviour follows manufacturer service bulletins NTB20-060A, NTB22-021 and the related judder detection revisions, and the Chevrolet Spark case follows GM Special Coverage N192271110. Platform specification data — ratios, torque capacity, valve body and pulley references — is the same set published in our JF015E / RE0F11A complete technical guide.
What does P0776 mean on a JF015E?
It is a performance code, not an electrical one. The control unit compared the target secondary pressure with the actual secondary pressure and found a gap of at least 1.2 MPa sustained for 10 seconds, with the engine running and the selector out of P or N. Published probable causes are the valve body assembly — a faulty secondary pressure solenoid valve — or the CVT assembly itself. Practically, it means hydraulic inspection: valve body, bores, solenoid performance and fluid condition.
Is P0965 the same fault as P0776?
No. They concern the same solenoid but describe different failures. P0776 says the pressure produced did not match the command — a hydraulic result. P0965 says the control circuit itself is outside its permitted range — an electrical condition. If only P0965 is stored, check the connector and harness first; a cracked connector on this platform can imitate an internal fault exactly.
Why do P0776 and P0841 appear together so often?
They are two views of one event. P0776 reports the pressure mismatch, P0841 reports that the pressure sensor's reading is not plausible for the commanded state. The pairing is a strong signal to inspect hydraulics rather than replace a sensor.
Can I keep driving with P17F0 or P17F1?
Short distances to a workshop, if the car still moves. Judder codes mean the belt is intermittently losing grip, and every occurrence polishes the pulley faces a little further. The difference between a valve body repair and a complete assembly is often how long the car was driven after the light came on — and the debris that a slipping belt leaves behind contaminate the new hydraulics if the pulleys are already scored.
Will a new valve body fix P0730?
Almost never on its own. P0730 reports an incorrect actual ratio, which is a mechanical outcome — belt and pulley faces. A valve body can restore clamping pressure, but it cannot restore a worn cone surface. Expect the pulley set and belt to be needed as well, or a complete assembly.
Do I need the TCM software update before replacing the valve body?
Yes, verify the software level first. The manufacturer revised judder detection thresholds through service bulletins, so an unupdated unit may report judder earlier than necessary. But understand what an update does: it changes how soon the unit reports a problem, not whether the hardware is worn. Reflash first, then re-test — never treat a reflash as a repair.
My codes cleared after a fluid change. Is it fixed?
No, and this is the most expensive misunderstanding in the trade. Fresh correct fluid restores pressure behaviour temporarily, which is enough to clear a marginal code. If the bore or the belt surface is worn, the code returns — usually within a few thousand kilometres, and often with more debris in the fluid. Use the cleared window to get a fluid sample analysed rather than as proof of repair.
What do you need from me to confirm the right part?
The full stored code list (current and pending), the transmission code from the housing, the VIN, a photograph of the original valve body showing the solenoid side, and the fluid condition with mileage. With those we confirm the variant and part number, stock and lead time in writing within four business hours. MOQ is one piece.
Send the code list and a photo of the original valve body. We will tell you which part the codes actually point at, and what it costs to ship — in writing, before you order.