I'm starting a list of all the C-HR operating modes. Please comment with any I missed.

OFF - everything is off except intermittent data communications with Toyota and/or the Toyota app will occur.

ACC - don't ever use; it drains the 12V and you will quickly get a warning on the multi-information display.

ON - don't use except briefly such as to open or close window(s); it drains the 12V and you will quickly get a warning on the multi-information display.

READY - puts the EV in drive ready status, and while in Park it will nicely charge the 12V battery. If you exit the vehicle while still in READY, the multi-information display will ask you if you want to have it turn off in one hour. If you do not reply to say NO, it will turn off in one hour. (It's not particularly wise to say no, as you may forget to come back and turn it off.) You cannot lock the car by touching the door handle or with the key fob, but you can lock it with the metal key and then re-open it with the metal key.

Remote ON - turns on Climate but is not "READY" and cannot be driven, even with key fob in the car.

Waiting to charge mode - plugged in to power but waiting to charge based on programmed schedule. You cannot go into READY mode and cannot drive the car. You can exit and lock the car normally.

Charging mode - same as OFF except if you open the door, the charging status displays very briefly on the multi-information display (not long enough to read) and alternates with the "Door Open" warning (left on screen for plenty of time). You cannot go into READY mode and cannot drive the car. You can exit and lock the car normally. If you plug in to charge with the vehicle is in READY mode, the EV immediately turns off.

My Room mode - same as charging mode, but if you press POWER once (ACC shows, or the screen may not respond at all - weird!⁠) then press again (displays ON) (all _without_ stepping on the brake pedal), the multimedia display will ask if you want to use Climate and audio system. If you use these, you will get warnings that will either say this slows your charging or that your Climate use is using as much power as the incoming charging power.

Initially experienced a dead 12V requiring a jump start within one week of purchase. Prior posts here (long post with data):

https://www.reddit.com/r/ToyotaCHR/s/t1LzT5wBnr

and here (TAS case created):

https://www.reddit.com/r/ToyotaCHR/s/japyvygf5l

Updates:

1. Battery testing.

I wanted to test the 12V battery itself with no dark energy uses, so I disabled Connected Services, signed us out of both Toyota app accounts, fully charged the battery with an external charger, and measured the battery for several days with no usage, only parked in the garage. Here is what I found:

Date || Time || Measured Voltage || Calculated State of Charge || Comments

7/18	10:30 a.m.	12.1	53%*	Overnight, apparently lost some charge from last night’s drive. Then 2 mi r/t.
	11:55 a.m.	12.24	63%**	Small gain from recent drive.
	12:00 p.m.			On external charger in bulk state
	2:15 p.m.			On external charger in 80%+ state
	2:40 p.m.			On charger, fully charged
	3:00 p.m.	13.1	100%**	Taken off charger, Connected Services disabled in Toyota app, both users logged out of app.
	4:00 p.m.	12.67	99%**	May reflect some surface charge
	9:45 p.m.	12.51	90%*	-9% SOC in 5.75 hrs.
7/19	11:00 a.m.	12.37	75%*	-15% SOC in last 12.25 hrs.
	11:30 a.m.			Turned on to READY briefly to verify WiFi was turned off (it was)
	5:00 p.m.	12.32	70%*	-5% SOC in last 6 hrs.
	10:00 p.m.	12.28	67%*	-3% SOC in last 5 hrs.
7/20	10:00 a.m.	12.23	63%*	-4% SOC in last 12 hrs. Net loss 0.44V or 36% of SOC since 7/18 4:00 p.m.
				Returned to “normal” use without monitoring

Observations: It lost charge faster than I would like to have seen, but it did hold itself well within decent, usable range after nearly two days at rest.

Having viewed this data and after talking with Toyota per our TAS case, the dealer offered to replace our battery as basically a good will gesture, since it passed their testing 3x. I said we wanted to run it in "normal" mode, stop testing, and see how it went, but would keep that option open.

2. NOW, here's what's interesting!

After doing this, I re-enabled Connected Services and logged both of us back into our Toyota app accounts. Our profiles on the car were still there but were messed up randomly here and there. It took about 3 days of fiddling to get them all reset, re-link the key, re-take face image for recognition, etc.

BUT: Since doing all this, the 12V has been doing fine.

A few times, I have used remote to check status and also to pre-cool the car before getting in (for maybe 3-5 minutes max).

A couple times, I have spot checked the 12V and found it to be 12.2 and 12.35. Still in the lower range, but still quite usable for starting.

It is possible that resetting everything actually helped? Or that Toyota has quietly rolled out an OTA update?

Anyway, I will keep an eye on this and report back if things change.

It's not on the lens surface or anything you can touch on the front of the car. It's actually quite visible whenever the beam hits anything including the road surface. This is a 2 mo. old car, and I don't think it was there originally but not sure. Just noticed it last night and it is distracting.

Images show both, then left, then right. L & R are similar shape, but L is much more pronounced. Nothing is visible looking at the lens and bulb to the extent you can see anything at all in there when the headlights are off. This is low beam only. They go away with high beam.

Does everyone have this?

https://preview.redd.it/tcj9tp21l7gh1.jpg?width=4032&format=pjpg&auto=webp&s=2caeba860daaff32e09e07ea225848ccadefb281

https://preview.redd.it/2xjdir21l7gh1.jpg?width=4032&format=pjpg&auto=webp&s=bfe6f58310c4a1efae41678004c6260ff868f7f4

https://preview.redd.it/7g8awp21l7gh1.jpg?width=4032&format=pjpg&auto=webp&s=e49320af859a33f935dc987af1086ccb095d5b55

NOTE 1: If you did not get hard copies of these with your car, look in the center console, under the removable tray at the bottom.

NOTE 2: Some owner's manuals are linked in the Toyota app if you are registered and signed in, under the dashboard page (color image of car) > INFO button > Glovebox > Manuals & Warranties, however I have not found these to be complete.

Owner's Manual - US:

https://www.manua.ls/toyota/c-hr-bev-2026/manual?p=1

also:

https://assets.sipb.toyota.com/publications/en/om-s/OM42K37U/pdf/OM42K37U.pdf

Owner's Manual - Canada:

https://www.toyota.ca/content/dam/toyota/documents/manuals/en/OM42K37U/OM42K37U.pdf

Owner's Manual Excerpt for Driving Support Systems - [US?]:

https://www.toyota.com/content/dam/toyotaowners/dom/add-driver-pdfs/2026/c-hr-bev/MY26_C-HR_OM_Excerpt_for_Driving_Support_Systems_D1_ML_1223.pdf

Owner's Manual Quick Reference Guide - [US]:

https://assets.sipb.toyota.com/publications/en/om-s/OM42K50U/pdf/OM42K50U.pdf

Owner's Manual Quick Guide - Canada:

https://www.toyota.ca/content/dam/toyota/documents/manuals/en/OM42K50U/OM42K50U.pdf

Charging Cable User Manual - Canada [may be same for US?]

https://www.toyota.ca/content/dam/toyota/documents/manuals/en/PT943-42010-NC-U/PT943-42010-NC_CAN_EN_Toyota_NACS_32A_DV_Manual.pdf

Multimedia Owner's Manual - US:

https://assets.sia.toyota.com/publications/en/omnav-s/OM42K44U/pdf/OM42K44U.pdf

Multimedia Owner's Manual - Canada:

https://www.toyota.ca/content/dam/toyota/documents/manuals/en/OM42K44U/OM42K44U.pdf

Warranty and Maintenance Guide - US:

https://assets.sipb.toyota.com/publications/en/omms-s/T-MMS-26CHRBEV/pdf/T-MMS-26CHRBEV.pdf

Owner's Manual Supplement [warranty, maintenance] - Canada

https://www.toyota.ca/content/dam/toyota/documents/manuals/en/OM26262U/OM26262U.pdf

Cross-post.

https://www.reddit.com/r/ToyotaCHR/comments/1v4jqyr/12vdcm_summary_of_some_available_toyota_subaru/

Cross-post.

https://www.reddit.com/r/ToyotaCHR/comments/1v4jqyr/12vdcm_summary_of_some_available_toyota_subaru/

Prepared by ChatGPT. I have reviewed some but not all of the original documents to the extent available, but don't have time to proof check everything, but the summary seems to be in good order.

NOTE: Some documents involve prior model years and are not up-to-date with current models, features, and/or technology.

Summary of publicly available information

Toyota public documents located:

• EL008-06 — General parasitic-current measurement procedure.
• T-SB-0089-21 — DCM reset and firmware update addressing several telematics issues, including "Depleted 12V vehicle battery when in IG-OFF."
• T-TT-0737-23 — Reference document directing technicians to the internal TDG-23 guide.
• TDG-23 itself was not located publicly.

Subaru public document located:

• 15-308-23R — Detailed diagnostic procedure specifically describing DCM standby-current testing, DCM communication pulses, graphing measurements, and DCM isolation during parasitic-draw diagnosis.

Toyota TSB EL008-06

Title: Parasitic Draw Measurement
Document ID: EL008-06
Date: June 19, 2006
Applies to: 2005–2006 Toyota Sequoia and Tundra equipped with Intelligent Power Outlet (IPO)

Available document:

• CHARM copy of EL008-06

Purpose

Provides a procedure for measuring parasitic (standby) current so that excessive electrical draw can be accurately diagnosed. 

Procedure highlights

• Keep continuous electrical contact to the battery during test setup.
• Turn ignition ON, then OFF.
• Lock all doors.
• Wait at least 120 minutes for ECUs and the Intelligent Power Outlet system to enter sleep mode.
• Use a multimeter capable of measuring in 1 mA increments.
• Connect the meter in series with the battery negative cable.
• Record the parasitic current.

 

Current measurement guidance

The bulletin includes a graph of acceptable standby current and states:

• The average parasitic draw should be calculated by averaging the minimum and maximum current levels.
• If the average exceeds the acceptable specification, the source of the excessive draw should be identified and isolated.

 

Toyota TSB T-SB-0089-21

Title: DCM Reset and Firmware Update
Document ID: T-SB-0089-21

Public copy (NHTSA):

• https://static.nhtsa.gov/odi/tsbs/2022/MC-10220179-9999.pdf

Purpose

Addresses certain telematics/Data Communication Module (DCM) conditions by resetting the DCM and updating its firmware.

Symptoms listed

Among the listed customer symptoms is:

• Depleted 12-volt vehicle battery when in IG-OFF

Other listed symptoms relate to telematics operation. (See bulletin for complete list.)

Procedure

The bulletin instructs technicians to:

• Perform a Health Check.
• Clear diagnostic trouble codes (DTCs).
• Disconnect battery power for the specified time.
• Reset the DCM.
• Verify current firmware.
• Update the DCM if required.
• Confirm proper operation after the update.

The bulletin does not describe standby-current waveforms, DCM current pulses, or oscilloscope/graphing procedures.

Toyota Tech Tip T-TT-0737-23

Title: Telematics Diagnostic Guide and References
Document ID: T-TT-0737-23

Available document:

• https://static.nhtsa.gov/odi/tsbs/2023/MC-10244111-9999.pdf

Purpose

Introduces Toyota's internal Telematics Diagnostic Guide (TDG-23) and explains where technicians can locate it within Toyota's Technical Information System (TIS).

Topics referenced

The guide references diagnostic information for:

• Safety Connect
• Service Connect
• Remote Connect
• Destination Assist
• Wi-Fi Hotspot
• Alexa
• Cloud Navigation
• Connected Technologies Platform (CTP)
• General telematics diagnostic flowcharts
• Customer interview worksheets

The Tech Tip itself contains references to the guide but does not include the full TDG-23 content.

Toyota Telematics Diagnostic Guide (TDG-23)

Availability

No public copy of TDG-23 was located.

Toyota indicates it is available within the Toyota Technical Information System (TIS) under Diagnostics → Telematics.

Based on the publicly available Tech Tip, TDG-23 appears to contain:

• Diagnostic flowcharts
• Customer interview worksheets
• Telematics feature diagnostics
• Reference material for Connected Services

No public copy describing DCM current waveforms or parasitic-current patterns was located.

Subaru Service Bulletin 15-308-23R

Title: Diagnostic Information – Testing Telematics Systems for Dark/Standby Current
Document ID: 15-308-23R
NHTSA ID: MC-11008263-0001 (2024 revision)

Available documents

• NHTSA PDF (2024 revision)
• OEMDTC summary

Purpose

Provides a detailed diagnostic procedure when the Data Communication Module (DCM) is suspected as the source of excessive dark (standby) current. 

Preparation

Technicians are instructed to:

• Use a DVOM capable of measuring 1 mA.
• Verify battery condition before testing.
• Disconnect aftermarket accessories.
• Turn ignition OFF.
• Close and lock all doors.
• Wait at least 55 minutes before measuring standby current.

 

Diagnostic requirements

The bulletin instructs technicians to:

• Clear telematics DTCs before diagnosis.
• Collect DCM data.
• Collect Central Gateway data.
• Perform battery testing.
• Photograph current measurements.
• Submit supporting information before DCM replacement in specified situations.

 

DCM current behavior

The bulletin states that:

• The DCM current draw occurs in pulses while communicating with the cellular network.
• These current pulses should not automatically be interpreted as a fault.
• A graphing DVOM is preferred because it allows evaluation of current over time.
• The DCM can exhibit multiple standby-current operating states.
• Poor cellular coverage can increase communication attempts during testing.
• Signal strength should be verified before concluding that the DCM is defective.

 

If DCM is confirmed as the source

The bulletin instructs technicians to:

• Isolate the DCM electrically.
• Confirm that the standby-current draw follows the DCM.
• Replace the DCM only after the specified diagnostic procedure confirms it as the source.

Infotainment screen seems too bright even when it switches to dark mode (manually or automatically). I have to go into settings and turn down the screen or turn it off (not an option if navigating).

Ambient lighting is reflected in the side windows and hits right where you need to look at the side mirrors. Again, I have to go into settings (driver Preferences) and turn illumination down or off.

Any other ideas or ways this can be automated.

Ours is the BVE model and XSE trim, if that matters.

1. Settings > Vehicle Customize (or Car Settings) > Door Lock Settings

"Lock Door When Opened" (a poor translation, apparently) means you can lock all the doors even when one is (and maybe more are) still open. It locks the closed doors and when the last door is shut it locks that and gives you one final beep to confirm all is locked.

Note: this is like the rear hatch when "close and lock" is pressed. Once it is closed and all locked, it gives you a final confirming beep.

I left this ON.

2. Settings > Vehicle Customize (or Car Settings) > Two Press Unlock

[I did know this from initial settings]

When this is "ON", one press will open the driver's door and a second press is needed to open all the others. When this is "OFF", one press opens all the doors.

This can be a security precaution for some people who prefer to only open their own door to get in. However, I left this one OFF.

3. Whose driver profile gets priority when there are two drivers with saved profiles, and two key fobs in the car, and also what if there are two saved face identifications?

a) When two key fobs enter the car, the one that enters the driver's side controls. If the door is locked and the driver with a key fob opens that door, the car automatically loads that driver's profile, seat and mirror positions (XSE) and infotainment preferences including preferred phone, Car Play or Android Auto, saved radio stations, etc. The passenger's key is registered as a secondary key for that trip. (NOTE: this assumes the key has been registered to the driver's saved profile, i.e. Preferences.)

b) As between key fob and face identification, the key fob wins the initial round when the car is opened and/or driver's side entered. The moment a driver sits down and faces the camera, if their face is recognized, the face recognition will override the key fob settings if they are not the same.

4. [Learned this the other day from a Reddit post.] If S-Flow (Smart Flow) is enabled, it will only direct climate air to the persons detected in the car when the car is started. That means if you pick up a passenger or someone else enters the car after it is started, they will not be detected, so for example, air may not be directed to the rear seats. The options are to select the Climate controls and turn off S-Flow, which then stays off unless reset later, or to restart the car for fresh detection.

Reportedly, there is a mechanism to detect which doors were opened before the car is started, so that if a rear door is open, but you get in and start the car without the passenger entering, that passenger will still be detected based on the door having been opened before the car was started. I have questions about this, because I do not know how the car distinguishes between opening the rear door for a passenger to enter vs. opening it to set down a coat or a package. However, people say the system is not based on detection of weight of a passenger in the seat, but rather on the door status. I do wonder, too, if it detects passenger presence by seatbelt connections, because it definitely monitors for that. That is shown on the dashboard (multi-information) display: it will show three rear passenger seat belt icons in red if none is connected.

Edit1: With S-flow ON, I turned the car off, locked it, unlocked it, opened and closed the rear door, then got in and started the car. There was no air flow to the rear seats. I then turned if off, locked it, unlocked it, opened the rear door, buckled one of the seat belts, closed the rear door, got in and started the car, and there as again no flow to the back seats. With S-flow OFF, there is air flow to the rear. So it is not using door opening nor seat belt closure to enable rear air flow. Must we weight detection, but I don't have a helper handy to test now.

Another Reddit user asked a really excellent question that I think we should discuss. (Lost the original thread, so can’t link it.)

Several users have posted that one should turn off the DCM by disabling Connected Services on the Toyota app. Another user asked, “If I disable the communications, can I re-enable them if I want to use them?” The answer was yes.

Another user then asked, “If communications are disabled, then how does the app communicate with the car to re-enable communications”? This is a great question.

Similarly, before the user first gives permission through the app to enable Connected Services, which also shares data with Toyota, the app must be able to communicate with the vehicle to enable them.

This means that even when Connected Services are disabled, the vehicle is able to communicate with Toyota and the app on a moment’s notice. There is not a day or hour delay, so it must be open continuously or available to ping and respond within moments. The DCM must be running continuously.

Let’s discuss how this is possible, and what it means for 12V battery draw when Connected Services are disabled. (I do not know the answers.)

Toyota App Inventory Index — 2026 Toyota C-HR EV

Vehicle Page (center icon from bottom row)

Top Center Drop-Down Arrow → Vehicles Page

Purpose:

• View vehicles associated with the Toyota account
• Add another vehicle
• Select which vehicle the app is currently controlling

Functions:

• Current vehicle selection
• Add vehicle

Top Right Person Icon → Account Area

The person icon opens:

Account Button

Contains:

Personal Info

• User account information

Manage Saved Profile

• Saved profile management

Notification Settings

• App notification preferences

Music Streaming

• Linked music service options

Security Settings

Includes:

• Password
• Face ID
• PIN
• Communication options

Drive Connect Settings

Includes on/off sliders for:

• Allow Notifications
• Cloud Navigation
• Maintenance & Fuel

Weather

• Weather feature on/off slider

Help and Feedback

• Support/contact options

Privacy Portal and Legal Info

Contains:

Vehicle Specific Settings

Includes:

• Vehicle Connectivity
• In-Vehicle Privacy Settings

Connected Services Legal Info

• Legal information relating to Connected Services

End User License Agreements

• Software/service agreements

Your Personal Information

• Privacy options relating to personal data

Person Icon (without opening Account)

Also contains:

• Inbox
  • Notifications
• Take a Tour
  • App orientation/help
• Appearance
  • App appearance settings

Three Main Tabs on Vehicle Page

• Remote
• Status
• Health

Persistent information shown with all three tabs

(Appears regardless of whether Remote, Status, or Health is selected)

EV Battery Information

• Traction Battery Status
  • Estimated remaining range (miles)

Charging / Navigation

• Find Station button

Remote Tab

Vehicle Image Control Panel

(The vehicle image appears only on this tab)

Vehicle Information / Controls

• Vehicle image
• Info button

Info Button Menu

• Glovebox
• Subscriptions
• Connected Services Support
  • Currently does not accept VIN
• Siri Shortcuts

Remote Action Controls

Buttons/icons include:

• Start
• Lock
• Unlock
• Other remote actions

Climate Controls

• Climate Settings button
  • Remote climate/preconditioning functions

Status Tab

Vehicle Status

Tire Pressure

• Vehicle graphic showing each tire
• Individual tire pressure information

Doors

• Door status

Windows

• Window status

Hatch

• Hatch status

Health Tab

Vehicle Health Information

Safety Recalls

• Recall information

Vehicle Alerts

• Vehicle warnings/notifications

Maintenance Schedule

• Service and maintenance information

Key Fob

• Key fob battery status

Info → Subscriptions

Trial Services

Active trials:

Service	Status
Safety Connect	Active trial
Service Connect	Active trial
Drive Connect	Active trial
Remote Connect	Active trial

(Toyota currently includes trials of 3 or 5 years depending on the specific service.)

Bottom Navigation Bar

Button	Function
Service	Service-related functions
Pay	Payment-related functions
Shop	Shopping/services
Vehicle icon	Opens vehicle page
Find	Search/location functions

Sent a lot of info/data/graphs to my service manager and they are creating a TAS case with Toyota. Hopefully this will help with diagnostics and company-wide awareness. They did say there are no open recalls or TSBs on this issue at this time.

| Date | Time | Value | State of Charge | Comment |

|------|------------|-------|-----------------|-----------------|

| 7/1 | 11:15 a.m. | 12.9 | | On arrival home |

| 7/2 | 11:15 a.m. | 12.9 | | On arrival home |

| 7/3 | 11:15 a.m. | 12.9 | | On arrival home |

| 7/4 | 11:15 a.m. | 12.9 | | On arrival home |

Cross-post because from the Toyota family and addressing a similar battery issue as here.

https://www.reddit.com/r/LexusRZ/s/T3BdKDNibo