HELP bike is throwing codes

atomsplitter said:
Looked up in the shop manual:
P1640- Roll Over detection disabled due to Inertial Measurement Unit (IMU) malfunction

P1695 - CAN fault - lost communication with instrument panel

P16A2 - Engine ECM detects IMU present but with signal error

It points to the IMU having a problem. If the fault is cleared after 40 start cycles the MIL light will clear or just use TuneECU and clear them and see if they come back.

Shop Manual Instructions:
Make sure ABS modulator connector is secure. Check for associated DTC C1713, perform tests for this DTC. Reset DTCs, if problem persists contact Triumph service.

Description of system:
IMU (if fitted) The Inertial Measurement Unit measures the following:
• Longitudinal acceleration
• Vertical acceleration
• Lateral acceleration
• Pitch rate
• Yaw rate
• Roll rate

From these measurements the IMU calculates the motorcycle's lean angle. The IMU outputs are used for multiple systems, for example, optimised cornering ABS (OCABS) and fall detection. If the IMU is fitted, the fall detection switch will not be fitted.

Here Comes the Bad News:
On the Rocket 3, the IMU is mounted on the frame (typically under the tank or near the ABS modulator). Replacement involves:

1. Remove bodywork to access the IMU​

Usually:

  • Seat off
  • Tank lifted or removed
  • Side panels off
The IMU is a small rectangular sensor with a single multi‑pin connector.

2. Disconnect the IMU harness​

Triumph uses locking connectors — depress the tab and slide the connector out.The manual specifically tells you to verify the ABS modulator connector is secure when diagnosing IMU faults , because the IMU shares CAN communication paths.

3. Unbolt the IMU​

It’s mounted with 2–3 small bolts.Important: The IMU must be mounted perfectly level. Triumph uses fixed mounting points so alignment is automatic.

4. Install the new IMU​

Bolt it in, reconnect the harness.

5. Clear DTCs and verify communication​

The manual says:

  • Clear DTCs
  • If the problem persists, contact Triumph service
This is because the IMU is part of the CAN network, and the ECM must detect it and validate its signals.

6. Perform IMU calibration (dealer tool only)​

Triumph’s diagnostic system (Triumph OBD/DealerTool) performs:

  • IMU initialization
  • Zero‑angle calibration
  • CAN handshake
TuneECU cannot perform IMU calibration — it can only clear codes.

Your current tab shows the IMU‑related fault codes:

  • P1640 – Roll‑over detection disabled due to IMU malfunction
  • P1695 – CAN fault, lost communication with instrument panel
  • P16A2 – ECM detects IMU present but with signal error
These codes strongly suggest:

  • Either the IMU is unplugged, water‑damaged, or internally failed
  • Or the CAN line between IMU → ABS modulator → ECM is compromised
Because the IMU is part of the safety system (cornering ABS), Triumph requires calibration after replacement.

Here's The Good News:

Before replacing the IMU, check these first​

These are directly from the manual:

  • Check ABS modulator connector (IMU shares CAN path)
  • Check for DTC C1713 (ABS/IMU communication fault)
  • Clear DTCs and see if they return
A loose ABS connector is far more common than a failed IMU.
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Hey! Just a small request—would you mind not replying with just "AI" to technical help posts? People are usually looking for actual solutions, so if you have any advice or experience to share, I'm sure it'd be really appreciated. 🙂

Sure, AI can be helpful on a surface level, but what's next? Has it actually read the entire 1,500-page factory service manual for that specific model? Has it understood the procedures, service bulletins, and model-specific quirks? AI is a tool, not a substitute for technical knowledge or experience.
 
imcool said:
Hey! Just a small request—would you mind not replying with just "AI" to technical help posts? People are usually looking for actual solutions, so if you have any advice or experience to share, I'm sure it'd be really appreciated. 🙂

Sure, AI can be helpful on a surface level, but what's next? Has it actually read the entire 1,500-page factory service manual for that specific model? Has it understood the procedures, service bulletins, and model-specific quirks? AI is a tool, not a substitute for technical knowledge or experience.
Click to expand...
Correct, it's a place to start. And probably should be consulted before posting here. What I don't want to see is a post go unanswered like no one cares or is too trivial. I am also happy to share what I've learned over the decades of Triumph ownership, but that doesn't mean I know everything there is to know about every model. If it gets the community talking and working together for a problem solution, I'm thinking I did my part to help a brother (sister). And I have posted a few times some very technical answers (which are usually very long and very detailed (including the math and formulas)). But I get your point, I'll try not to post just an AI in future.
 
I took apart the rear blinker as I saw my left blinker was bent and the wires were pulled on. took it apart and put it back together. Took the seat off and reconnected the battery after having it off for about 36hrs (due to the bike making a weird whining noise). hit the power switch, cleared the fault codes, turned the bike off and back on, and started the engine. Codes were gone! Must have been a short somewhere possibly near the rear blinker? Very strange.
 
NicholasRocket92 said:
I took apart the rear blinker as I saw my left blinker was bent and the wires were pulled on. took it apart and put it back together. Took the seat off and reconnected the battery after having it off for about 36hrs (due to the bike making a weird whining noise). hit the power switch, cleared the fault codes, turned the bike off and back on, and started the engine. Codes were gone! Must have been a short somewhere possibly near the rear blinker? Very strange.
Click to expand...
you are lucky it didnt fry your instrument dash,
there is no relay running blinkers on rocket 2.5, blinkers are being turned on/off from instrument cluster by chip inside instrument, so any short in blinkers will fry instrument

I have been there and done that, replacement was 1500USD

I have installed fuses in on rear blinker power rail to make sure instrument never burns again
 
imcool said:
you are lucky it didnt fry your instrument dash,
there is no relay running blinkers on rocket 2.5, blinkers are being turned on/off from instrument cluster by chip inside instrument, so any short in blinkers will fry instrument

I have been there and done that, replacement was 1500USD

I have installed fuses in on rear blinker power rail to make sure instrument never burns again
Click to expand...
That's a good idea. Might end up doing that.
 
NicholasRocket92 said:
That's a good idea. Might end up doing that.
Click to expand...

I did electronics measurement and battery drain calculation for rocket3R 2022 - Battery, Turn signals

Hello All, Hope it helps someone - Stock blinkers are 2watts 12V LED Array in each blinker/turn signal so they are consuming 167Milliamps per blinker. - When bike is completely OFF and Key Fob is ON and in range then motorcycle drains battery at 80Milliamps. - When bike is completely OFF and...
www.r3owners.net www.r3owners.net


use/refer to measurement here I did, so you can use correct value of fuses , putting bigger value fuse is same as putting no fuse.
 
atomsplitter said:
Correct, it's a place to start. And probably should be consulted before posting here. What I don't want to see is a post go unanswered like no one cares or is too trivial. I am also happy to share what I've learned over the decades of Triumph ownership, but that doesn't mean I know everything there is to know about every model. If it gets the community talking and working together for a problem solution, I'm thinking I did my part to help a brother (sister). And I have posted a few times some very technical answers (which are usually very long and very detailed (including the math and formulas)). But I get your point, I'll try not to post just an AI in future.
Click to expand...
I enjoy your responses and replies, and with any reply everyone needs to think, follow up.
 
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