Tongsheng Controller & Display Settings: A User’s Guide

If you own a Tongsheng mid-drive kit—most commonly the TSDZ2—you already know the motor delivers torque-sensing power that feels natural under pedal. But the display and controller settings are where you actually shape that ride. The good news: you don’t need a laptop or a dealer to adjust the basics. Most of what matters lives in the P-settings menu on the display itself.

This guide covers the settings that affect your daily ride: P-menu meanings, display unit changes, PAS level tuning, and error code readouts. We’ll also flag where the TSDZ2’s firmware differs from the older VLCD5 and VLCD6 displays, so you’re not hunting for a menu that doesn’t exist on your model.

What You Need Before Changing Settings

Before you start pressing buttons, gather two things:

1. Your battery’s nominal voltage. Check the label on the battery or the charger. This must match P3 on the display, or your battery gauge will lie to you.

2. Your true wheel diameter. Measure from the ground to the center of the wheel hub, then double it. For a 700x32c tire, that’s about 27.5 inches—not the 28 inches printed on the sidewall. This matters for P4.

You’ll also want to know your kit’s rated controller current. This is usually printed on the controller casing or listed in the product manual. Do not exceed it when adjusting P9.

One safety note: Make sure the bike is on a stand or the rear wheel is off the ground before testing throttle or PAS changes. The motor can deliver strong torque at standstill, and an unexpected surge can push the bike out from under you.

P-Settings Menu: What Each Number Actually Does

The P-settings menu is the display’s configuration layer. It controls how the motor responds to your pedaling, not just what the screen shows. To enter it, turn the display on, then hold UP and DOWN together for about 2 seconds until the P-number appears.

Here’s the breakdown of the settings that matter most for daily riding:

Setting	What It Controls	Typical Range	Notes
P1	LCD brightness	1–5	Higher = brighter; drains the display’s backup battery slightly faster
P2	Metric/Imperial units	0 = km/h, 1 = mph	Switch to 1 if you’re in the US and want miles
P3	Voltage class	24V / 36V / 48V / 52V	Must match your battery; a mismatch causes inaccurate battery bar readings
P4	Wheel size	Inches (e.g., 26, 27.5, 700c)	Critical for speed accuracy; a wrong value throws off odometer and speed readout
P5	Speed limit	15–40 km/h or mph	The controller cuts motor assist above this speed; check local class laws
P6	PAS level at startup	0–5	0 forces you to choose a level each ride; 1–5 restores the last-used level
P7	Throttle enable	0 = off, 1 = on	Only appears if your kit includes a throttle; not all Tongsheng kits ship with one
P8	Throttle mode	0 = pedal first, 1 = throttle direct	0 requires pedaling before throttle engages; 1 allows throttle from standstill
P9	Controller current limit	5–15A (varies by kit)	Higher = more torque, but more battery draw and heat
P10	Motor phase current	10–25A	Advanced setting; raising it increases low-speed torque but risks overheating the motor
P11	Pedal sensor type	0 = torque sensor, 1 = cadence	Leave at 0 for TSDZ2; the torque sensor is the whole point of this motor

Concrete example: If your speedometer reads 28 mph when you’re actually going 25 mph, the fix is almost always P4. Set it to your true wheel diameter—including tire width—not the nominal rim size. A 700x32c tire measures roughly 27.5 inches, not 28.

One warning: P9 and P10 are the settings that can damage hardware. Raising P9 above the kit’s rated controller current (check your specific model) can overheat the MOSFETs on long climbs. If you’re climbing steep grades regularly, a lower P9 with a higher P10 keeps torque available without cooking the controller. A good starting point for a 48V kit on hilly terrain is P9 at 12A and P10 at 18A—then adjust based on how warm the controller gets after a 10-minute climb.

Display Units and Basic Readouts: Making the Screen Work for You

The display does more than show speed. It’s your battery gauge, trip computer, and error-code readout. Here’s how to get the basics right.

Switching to Miles Per Hour

On the VLCD5 and VLCD6 displays:

1. Enter P-settings (hold UP + DOWN for 2 seconds).

2. Scroll to P2.

3. Set it to 1 for mph.

4. Exit the menu (hold UP + DOWN again).

The display will now show speed in mph, and the odometer will accumulate in miles. Note that P5 (speed limit) also switches to mph, so a setting of 20 means 20 mph, not 20 km/h.

Verification step: After exiting the menu, ride at a steady pace alongside a GPS app on your phone. If the display reads within 1–2 mph of the GPS at 20 mph, your P2 and P4 settings are correct. If the discrepancy is larger, re-check P4 first—it’s the more common source of error.

Understanding the Battery Bar

The battery gauge on Tongsheng displays reads voltage, not remaining capacity. This is an important distinction: a 48V battery at 50% state of charge reads about 48.0V under load, but the display’s bar may show 3 of 5 segments. The bar is a rough estimate, not a fuel gauge.

Practical rule: If the bar drops to 1 segment under load but recovers to 3 when you stop pedaling, your battery is nearing empty or is suffering from voltage sag. A healthy battery holds voltage better under load. If you see this pattern with a battery that’s less than a year old, check the connection between the battery and the controller—loose Anderson connectors are a common cause of intermittent voltage drops.

Failure mode to watch for: If the battery bar shows full for the first 10 miles, then drops from 5 to 1 segment in under 2 miles, your P3 setting is likely wrong. A 48V battery set to 36V in P3 will appear full until the voltage drops below the 36V threshold, then suddenly plummet. This is one of the most common setup mistakes on used kits.

Trip and Odometer Functions

The VLCD6 has a trip distance (TRIP) and total odometer (ODO) readout. To reset the trip, press and hold the DOWN button for 3 seconds while on the TRIP screen. This is useful for tracking per-ride distance, especially if you’re comparing range across different PAS levels.

PAS Levels and Torque Sensing: Tuning Assist to Your Legs

The TSDZ2’s torque sensor measures how hard you push the pedals, then the controller multiplies that force by the PAS level. This is fundamentally different from cadence-sensing motors, which just detect that the pedals are turning.

What Each PAS Level Means

• PAS 0: No motor assist. You’re riding the full weight of the motor and battery.
• PAS 1: ~30% assist. Good for flat terrain or when you want a workout with a light tailwind.
• PAS 2: ~50% assist. The default for most commuting; balances range and effort.
• PAS 3: ~75% assist. Noticeable push on hills; drains battery faster.
• PAS 4: ~100% assist. The motor roughly matches your input force.
• PAS 5: ~150% assist (overdrive). Strong pull, but battery consumption rises sharply.

The torque-sensing nuance: Because the motor responds to force, not just pedal rotation, you control assist with your legs. Push harder, get more power. Ease off, and the motor backs down. This makes the TSDZ2 feel like a very strong pair of legs rather than a switch you flip on and off.

Adjusting PAS Behavior

If PAS 1 feels too weak and PAS 2 feels too strong, you have two options:

1. Adjust P9 (controller current limit) downward. This reduces the maximum assist across all levels, effectively compressing the range. A 48V kit set to 10A instead of 15A will feel gentler at every PAS level.

2. Change your riding style. Because the torque sensor responds to input, you can ride in PAS 3 but pedal lightly—the motor will only deliver what your legs ask for.

Evidence from the field: Many TSDZ2 owners report that PAS 1 on a 48V kit is nearly useless for anything but flat ground, while PAS 2 handles gentle hills. If you live in a hilly area, you’ll likely live in PAS 3–4 and accept the range hit. A 52V battery helps here: the higher voltage gives the motor more headroom before hitting the controller’s current limit, which translates to better hill-climbing at lower PAS levels.

Failure mode to watch for: If the motor surges hard when you start pedaling, even at PAS 1, the torque sensor may be mis-calibrated or the bottom bracket may be loose. A loose bottom bracket causes the torque sensor to read erratic input. Check for play in the crank arms before adjusting settings—tightening the bottom bracket may fix the surging completely.

Error Codes: What They Mean and How to Respond

Tongsheng displays show error codes as E0x (VLCD5) or 0x (VLCD6). These are diagnostic readouts, not just warnings. Here’s the list you’re most likely to see:

Code	Meaning	Likely Cause	Response
E01	Motor phase error	Loose or broken phase wire between controller and motor	Check the 3 thick wires (blue, yellow, green) at both ends; reseat connectors
E02	Throttle error	Throttle stuck or wiring short	Disconnect throttle; if error clears, replace throttle
E03	Motor hall sensor error	Hall sensor wire damaged or sensor failed	Check the 5-pin hall connector; if wires are intact, the motor needs service
E04	Controller overcurrent	Current draw exceeded controller limit	Usually transient; check P9 setting if it recurs on hills
E05	Controller overvoltage	Battery voltage exceeds controller rating	Check battery voltage; a 48V controller on a 52V battery can trigger this at full charge
E06	Controller undervoltage	Battery voltage too low	Charge the battery; this is the low-voltage cutoff
E07	Controller overheating	Motor or controller exceeded temperature limit	Stop and let it cool; reduce P9/P10 for sustained climbs
E08	Display communication error	Wiring between display and controller damaged	Check the display cable; this is often a loose connection at the display end

Concrete example: If you get E03 after hitting a pothole, the hall sensor wire inside the motor cable is likely pinched or partially pulled from its connector. The fix is usually reseating the 5-pin connector, not replacing the motor. If the error persists, the hall sensor board inside the motor housing may need replacement—a job that requires opening the motor casing.

Important note: The VLCD6 displays errors as numbers without the “E” prefix. A “03” on a VLCD6 is the same as E03 on a VLCD5. Don’t panic if you see a bare number; it’s the same diagnostic.

Verification step after fixing an error: Clear the error by powering the display off and on. Then ride for 5 minutes under normal load. If the error doesn’t return, the fix held. If it returns at the same point in your ride (e.g., always on the same hill), the issue is load-related—check P9/P10 rather than chasing wiring.

Model-Specific Differences: VLCD5 vs. VLCD6 vs. Aftermarket Displays

Not all Tongsheng displays are the same. The two most common factory options are:

• VLCD5: The older, simpler display. It has a smaller screen, fewer readouts, and a more basic button layout. P-settings are accessed the same way (hold UP + DOWN), but some advanced settings (like P8 throttle mode) may not appear if the firmware is older.

• VLCD6: The newer display with a larger screen and more data fields (speed, trip, odometer, battery, PAS level, and error codes). It also supports a walk-assist mode (hold DOWN for 2 seconds at standstill) that the VLCD5 lacks.

Aftermarket displays: Tongsheng motors use a proprietary communication protocol, but some third-party displays—like the GEERYZHE Bike Display LCD 5 Pin M5 Control Panel—are designed to work with No. 2 protocol controllers, which includes many Tongsheng kits. These displays often have a larger screen and additional readouts, but they require that your controller matches the No. 2 protocol. Check your controller’s label before buying; a mismatch means the display won’t communicate with the motor.

Firmware caveat: The TSDZ2 has an open-source firmware community (the “TSDZ2 Smart” firmware) that unlocks advanced settings like regen braking and custom torque curves. That firmware requires a programming cable and a Windows PC. It’s a significant upgrade path, but it’s beyond the scope of the stock P-settings menu. If you’re considering it, know that it voids the factory warranty and requires careful flashing to avoid bricking the controller.

Quick Troubleshooting: When Settings Don’t Stick

If you change a P-setting and it reverts after power-off, the display’s internal backup battery (a small coin cell) may be dead. The display needs this battery to retain settings when the main battery is disconnected. Symptoms include:

• Settings reset to defaults every ride.
• The clock (on VLCD6) resets to 00:00.
• The display occasionally fails to power on.

Fix: Open the display case and replace the coin cell (usually a CR2032). This is a 10-minute job with a small Phillips screwdriver. If the display is sealed, you may need to pry the case apart carefully—use a plastic spudger to avoid cracking the housing.

Another common issue: If P3 (voltage class) is set incorrectly, the battery bar will read wrong even with a fully charged battery. A 48V battery set to 36V in P3 will show full bars until it’s nearly dead, then drop suddenly. Set P3 to match your battery’s nominal voltage exactly.

Verification step for settings retention: After changing P2, P3, and P4, power the display off completely (not just standby) and wait 30 seconds. Power it back on and check that the settings held. If they reverted, the backup battery is the first thing to replace.

Frequently Asked Questions

Why does my Tongsheng display show km/h even after I set P2 to 1?

The P2 setting only affects the speed readout. If you’re looking at the odometer, it may still show kilometers until you reset it. Also, some early VLCD5 firmware versions ignore P2 entirely—check your firmware version against the Tongsheng support page.

Can I set the speed limit above 25 km/h for off-road use?

Yes, P5 can be set up to 40 km/h on most kits. However, if you ride on public roads, check your local e-bike class laws. In the US, Class 1 and Class 2 e-bikes are limited to 20 mph, and Class 3 to 28 mph. Exceeding these limits on public roads can affect your legal status.

My display shows E04 on every hill. Is my controller broken?

Not necessarily. E04 is overcurrent, which happens when the motor draws more current than the controller allows. This is common on steep climbs with a high PAS level. Lower the PAS level on climbs, or reduce P9 to keep current within limits. If it happens on flat ground, check for a dragging brake or a seized bearing.

Does changing P9 affect battery range?

Yes, directly. A higher current limit means the motor can draw more power, which drains the battery faster. If you’re chasing range, lower P9 and use a lower PAS level. The trade-off is reduced hill-climbing torque.

Will an aftermarket display void my warranty?

It depends on the seller. Some Tongsheng distributors honor the warranty if the display is swapped, others don’t. Check with your vendor before swapping. The motor and controller are the expensive parts; the display is a wear item.