TI-84 error · TI-84 error codes
TI-84 Error Codes List — Every Common Message and Its Fix
A TI-84 error code is not a diagnosis of a broken calculator. Almost every message reports something the calculator was asked to do that has no defined answer — dividing by zero, combining lists of different lengths, searching an interval whose bounds are reversed — and the correct response is almost always a specific, small change.
This page is the reference: every common message in one table, with a one-line meaning and the fix, and a link to the detailed page where the full explanation lives.
Two things are worth knowing before you read any message: what the choice 1:Quit does compared with 2:Goto, and the fact that an error message never costs you stored work.
How to read an error menu on a TI-84
ERR: SYNTAX
1:Quit
2:Goto
After pressing ENTER
1:Quit clears the message and returns you to the home screen with your entry still on the line, ready to edit. 2:Goto moves the cursor to the character or argument the calculator could not use. For a typing fault, Goto is the faster of the two because it turns the whole screen into a single highlighted character. For a setup fault — a reversed bound, an empty list, a window that cannot be drawn — there is no character to point at, and Quit is the sensible choice.
Some messages display only 1:Quit. That happens when the fault is found while the calculator is working rather than while you are typing: a memory shortage, an archived variable that cannot be touched, or an execution stopped with the ON key. With nothing to jump to, the single option simply clears the message so you can deal with the cause.
Inside a program, 2:Goto behaves slightly differently. It jumps to the program line that raised the error rather than to a character on the home screen, which is the standard way to find the instruction that is misbehaving.
The TI-84 error codes list
| Message | What it means | The fix |
|---|---|---|
ERR: SYNTAX | The calculator could not turn the line into a valid expression. | Find the unclosed bracket, stray comma or unused key. Full ERR: SYNTAX fix |
ERR: DOMAIN | A value you supplied lies outside the range the function accepts. | Check the input against the function’s domain; use a+bi mode if a complex answer is wanted. Full ERR: DOMAIN fix |
ERR: INVALID DIM | A plot, list or matrix dimension cannot be used at all. | Switch the stat plots off, clear stray entries, check the window. Full ERR: INVALID DIM fix |
ERR: DIM MISMATCH | One operation combined lists or matrices of different shapes. | Make the element counts or matrix dimensions agree. Full ERR: DIM MISMATCH fix |
ERR: BOUND | A numeric search was given bounds or limits in the wrong order. | Mark the left bound lower than the right, or swap the limits. Full ERR: BOUND fix |
ERR: OVERFLOW | A number is beyond the calculator’s range, which ends just below 1×10^100. | Scale the calculation, or work with logarithms of the values. |
ERR: UNDERFLOW | A number is too small for the calculator to represent distinctly from zero. | Rare on current models — TI’s TI-84 Plus CE reference guide does not list this message, so you are unlikely to meet it. |
ERR: UNDEFINED | You referenced a variable that is not currently defined. | Re-run the calculation that creates it. A stat variable is undefined after its list has been edited. |
ERR: ARGUMENT | A function or instruction was given the wrong number of arguments. | Compare the line with the syntax shown for that command, and separate arguments with commas. |
ERR: DATA TYPE | The wrong kind of value was supplied, such as a matrix where a list belongs or a complex number where a real one is required. | Store the value in the type the command expects; check the editor you are typing into. |
ERR: MODE | An instruction was used in the wrong graphing mode, or a window variable was stored in another mode. | Press MODE and choose the mode the instruction requires, then try again. |
ERR: STAT | A statistical calculation was given lists it cannot use, such as fewer than two data points or a negative frequency. | Check the list lengths and any frequency list, and confirm the histogram bin count is sensible for the window. |
ERR: SINGULAR MAT | The matrix has a determinant of zero, so it cannot be inverted. The CE reference labels the type SINGULAR MATRIX. | Rebuild the matrix with correct entries, or solve the system another way. |
ERR: NO SIGN CHNG | solve( or the equation solver found no sign change across the interval. | Widen or move the interval so the expression changes sign inside it, or supply a better guess. |
ERR: TOL NOT MET | The accuracy you asked for cannot be achieved for that expression. | Accept a looser tolerance, or rewrite the equation in a form the algorithm handles. |
ERR: ERROR IN XMIT | A link transmission failed, usually because of the cable or the receiving unit’s state. | Reconnect the cable, put the receiving unit in receive mode first, then send. Related link messages include MEMORYFULL, BAD ADDRESS and VERSION. |
ERR: ARCHIVED | A variable that is archived was used, edited or deleted. | Unarchive it in the memory menu, or choose a variable that is held in RAM. |
ERR: MEMORY | There is not enough free memory for the operation. Recursive definitions such as Y1=Y1, and a Goto that leaves a loop before its End, also raise it. | Delete unwanted items, unarchive variables, or restructure the program. A matrix over 400 cells is refused on the same grounds. |
ERR: ILLEGAL NEST | A function was placed where it cannot be nested, as in a seq( inside another seq(. | Rewrite the expression as two steps, storing the inner result first. |
ERR: BREAK | The ON key was pressed to stop a program, a DRAW instruction or a long evaluation. | Nothing is broken; decide whether to run the work again. Note that a program stopped partway may leave its own variables at intermediate values. |
ERR: WINDOW RANGE | The window variables cannot be drawn, for example Xmax at or below Xmin. | Press WINDOW and make Xmin smaller than Xmax and Ymin smaller than Ymax. |
ERR: BAD GUESS | The guess supplied is outside the bounds, or the points around it are undefined. | Place the guess inside the bounds and close to the expected answer. |
ERR: DIVIDE BY 0 | A division by zero was evaluated. This message is not raised while graphing, because undefined values are allowed on a graph. | Find the value that makes the denominator zero and exclude it, or use a complex mode if that is the intent. |
ERR: STAT PLOT | A graph was requested while a stat plot was switched on with an undefined list. | Open 2nd STAT PLOT and choose 4:PlotsOff, or define usable lists for the plot. |
What an error never does to your data
An error message is a refusal, not a write. When the calculator stops with ERR: DOMAIN or ERR: DIM MISMATCH it has declined to evaluate an expression and changed nothing in memory: your lists, matrices, programs, window settings and MODE choices are exactly as they were a second earlier.
That distinction matters because it tells you what not to do. The instinct after a stubborn message is to reset, and resetting is the one action that does destroy data — TI’s own guidance suggests a RAM reset as a last resort for INVALID DIM, warning that it erases programs, notes and data. So back up anything you need first. Our guide to resetting a TI-84 to factory defaults explains which reset level clears what.
Two genuine exceptions are worth stating honestly. First, ERR: BREAK stops a program mid-run, so the program’s own variables can be left holding half-finished values; the lists you entered by hand are untouched, but the program is best restarted from the beginning. Second, code that writes over a list will do so whether or not an error follows, which is a fault in the program rather than in the error system. See TI-BASIC programming if you need to trace that kind of overwrite.
The messages worth knowing properly
Five messages account for the great majority of what students actually see, and each has a dedicated page because the fix is longer than a table cell allows:
- ERR: SYNTAX — the parser could not read the line.
- ERR: DOMAIN — a value is outside the range the function accepts.
- ERR: INVALID DIM — the plot, list or matrix cannot be used as configured.
- ERR: DIM MISMATCH — two shapes disagree inside one operation.
- ERR: BOUND — a numeric search was given an impossible interval.
Reading those five properly is worth more than memorising the rest. Every other entry on the list either describes a rare situation, a programming fault, or a transmission problem, and all of them name themselves clearly enough that the table above is sufficient.
Fixing errors in a sensible order
- Read the title line and match it in the table above.
- Decide whether the fault is in what you typed or in the setup. Typing faults take
2:Goto; setup faults take1:Quitand a change to the configuration. - Change the specific value or setting the message points at, then re-run the operation rather than retyping the whole expression.
- If the message persists after a correct fix, check the window and the lists before considering a reset.
- If the message changes to a different code after your edit, treat that as progress: each message names a narrower fault than the one before.
Errors are part of using the calculator rather than a sign that it is failing, and the habits that avoid them — reading the line before pressing ENTER, checking the lists before a regression, framing the window before a search — are the habits that save time in an exam too. The calculator rules for the SAT, ACT, AP and IB papers are revised occasionally, so confirm the current wording with the official board and your teacher; our SAT calculator policy page sets out what is certain. To build the habits rather than repair the faults, start with graphing a function.
Frequently asked questions
What is the most common TI-84 error message?
ERR: SYNTAX, by a distance. It appears whenever the calculator cannot read the line you typed, and the usual cause is an unclosed bracket or a command used in the wrong place. ERR: INVALID DIM is the next most common, because a stat plot left switched on blocks the graph screen even when the function itself is correct.
Does an error message mean my calculator is broken?
Almost never. Most messages describe something the calculator was asked to do that has no answer, such as dividing by zero or combining lists of different lengths. The calculator is working exactly as designed when it refuses, and the exception is a hardware or battery fault that produces no message at all.
What is the difference between 1:Quit and 2:Goto on the error screen?
1:Quit clears the message and returns to the home screen with your entry still on the line so you can edit it. 2:Goto moves the cursor to the character or argument the calculator objected to. Goto is faster for a typing fault, but some system and memory messages offer only Quit because there is no line to jump to.
Can I lose my lists or programs because of an error?
No. An error message refuses an operation and writes nothing to memory. Deleting data is always something you do deliberately, through the reset menu or by clearing a list, so an error message on its own never costs you work.
Which error message should I learn first?
ERR: SYNTAX, because it is the one you will meet most often and the fix is a habit rather than a repair. Reading the whole line before pressing ENTER removes nearly all of them, and the same habit transfers to the on-screen calculator in the digital SAT's Bluebook app.
Official references
Statements on this page are checked against the manufacturer or exam authority documentation below. Where an official source and this page disagree, the official source wins.