Fixed - Battery upgrade to H8 - now brake light stays on, can't reset BMS

[R8er]

Hi, just replaced the oem battery with an everstart H8 AGM. I went to reset the BMS, but there is no battery light on the dash. I went ahead and tried the five/3 reset procedure, but it doesn't do anything.
Also get, check brake system warning when turning on ignition along with battery state of charge low message. Then the BRAKE light stays on even after making sure parking brake is not set.
Checked brake fuses under hood, 28 and 29, both look good. Are there any other fuses?
Battery voltage shows 12.3 in forscan. I made sure battery was charged all the way before installing.

current DTC:
Code: U3003 - Battery Voltage

Additional Fault Symptom 16):
- Circuit Voltage Below Threshold

Status (-AB):
- DTC Present at Time of Request
- Malfunction Indicator Lamp is On for this DTC

Module: Antilock braking system

Freeze Frame #1:
-EVENT_TIME: 104889815 s (Sun Feb 02 16:19:26 2025) - Event time
-TOTAL_DISTANCE: 45532 km - Total Distance
-MODULE_VOLTAGE: 14.3 V - Control Module Voltage
-OUTDOOR_TEMPERATURE: 10 °C - Outside temperature
-PWR_MODE_KEY: Running (Position 2) - Power Mode Key State
-ECU_POWER_SUPPLY: 14.1 V - ECU Power Supply Voltage
-ECU_F_RSC: Inactive - ECU System Flags - Roll Stability Control
-ECU_F_ABS: Inactive - ECU System Flags - ABS
-ECU_F_BTCS: Inactive - ECU System Flags - Brake Traction Control System
-ECU_F_TCS: Inactive - ECU System Flags - Traction Control System
-ECU_F_AYC: Inactive - ECU System Flags - Active Yaw Control
-ECU_F_HDC: Disabled - ECU System Flags - Hill Decent Control
-ECU_F_ESC: Inactive - ECU System Flags - Engine Drag Control
-ECU_F_TSC: Inactive - ECU System Flags - Trailer Stability Control
-TCS: INACTIVE - Traction control system
-EDC#1: INACTIVE - Engine Drag Control
-BTCS: INACTIVE - Brake Traction Control System
-AYC: INACTIVE - Active Yaw Control
-ABS: INACTIVE - Antilock braking system
-BFLHP: 0.0 kPa - Brake Fluid Line Hydraulic Pressure
-BRK_F_P_R: 0.0 kPa - Brake Fluid Line Hydraulic Pressure (Raw Value)
-IFC_D703: 121 - Internal Module Fail Code

Any help is appreciated. any fuses to check etc... anything else?

Thanks in advance!

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[SilverPigeon]

Have you tried rebooting the ABS module in service procedures?

 

[KingDavid]

No battery light on the dash? How is that possible? Are you turning the truck on to accessory mode? Or are you starting up the truck?

Anyway, if you haven't tried already, you can reset through forscan apparently? Hopefully someone can chime in on that.

 

[SilverPigeon]

No battery light on the dash? How is that possible? Are you turning the truck on to accessory mode? Or are you starting up the truck?

According to the frame, he was engine running. That does explain the lack of a battery tell-tale in the IPC, but not the aberrant ABS behaviour.

 

[Je1279]

I would try disconnecting the battery for ~20 mins then reconnect the positive terminal first followed by the negative terminal (with batteries, the negative cable should always be first off and last on). After that, perform the BMS reset procedure with the ignition in the on, but not run position. It may take ~10 seconds to see the battery icon flash notifying you that the procedure completed successfully.

 

[R8er]

So, just in accessory mode. Based on the voltage on DTC yes it was running. HOWEVER, when i just hit the button without starting, no battery light on dash. Does it think its running?
I can try to reset the ABS module if you think that might help.

Maybe I need to disconnect the battery for a while? I didn't have it disconnected long when I changed it out. Maybe 5 minutes at most.

 

[R8er]

did an ABS reboot. DTC comes right back.

Code: U3003 - Battery Voltage

Additional Fault Symptom 16):
- Circuit Voltage Below Threshold

Status (-AB):
- DTC Present at Time of Request
- Malfunction Indicator Lamp is On for this DTC

Module: Antilock braking system

Freeze Frame #1:
-EVENT_TIME: 104897975 s (Sun Feb 02 18:35:26 2025) - Event time
-TOTAL_DISTANCE: 45532 km - Total Distance
-MODULE_VOLTAGE: 12.0 V - Control Module Voltage
-OUTDOOR_TEMPERATURE: 11 °C - Outside temperature
-PWR_MODE_KEY: Ignition On (Position 2) - Power Mode Key State
-ECU_POWER_SUPPLY: 12.0 V - ECU Power Supply Voltage
-ECU_F_RSC: Inactive - ECU System Flags - Roll Stability Control
-ECU_F_ABS: Inactive - ECU System Flags - ABS
-ECU_F_BTCS: Inactive - ECU System Flags - Brake Traction Control System
-ECU_F_TCS: Inactive - ECU System Flags - Traction Control System
-ECU_F_AYC: Inactive - ECU System Flags - Active Yaw Control
-ECU_F_HDC: Disabled - ECU System Flags - Hill Decent Control
-ECU_F_ESC: Inactive - ECU System Flags - Engine Drag Control
-ECU_F_TSC: Inactive - ECU System Flags - Trailer Stability Control
-TCS: INACTIVE - Traction control system
-EDC#1: INACTIVE - Engine Drag Control
-BTCS: INACTIVE - Brake Traction Control System
-AYC: INACTIVE - Active Yaw Control
-ABS: INACTIVE - Antilock braking system
-BFLHP: 0.0 kPa - Brake Fluid Line Hydraulic Pressure
-BRK_F_P_R: 0.0 kPa - Brake Fluid Line Hydraulic Pressure (Raw Value)
-IFC_D703: 121 - Internal Module Fail Code

I did a reboot, then cleared DTC. Now this is the current one.

Going to disconnect battery for 30 minutes.

 

[Big Dog Daddy]

Dumb question, did you charge the battery fully before you installed it?

 

[R8er]

Dumb question, did you charge the battery fully before you installed it?

Yes, I did. Thanks!

 

[Big Dog Daddy]

Yes, I did. Thanks!

Last time I did a battery disconnect, I got a bunch of faults on startup after reconnecting the battery, I took it for a short drive and 1 or 2 ignition cycles later it all cleared and I did a bms reset after that.

 

[R8er]

Last time I did a battery disconnect, I got a bunch of faults on startup after reconnecting the battery, I took it for a short drive and 1 or 2 ignition cycles later it all cleared and I did a bms reset after that.

Good to know. Thanks for the info.
im waiting now with it negative disconnected. After 30 minutes ill see what it does and let you know.

 

[Big Dog Daddy]

You'll be fine, FYI, that battery light on the IPC is just a tiny little picture of a battery on the upper right side of the IPC.

 

[Gutshot]

To the OP.

The same thing happened to me a few weeks back.
I just let the truck sit all night, then the next morning I followed the BMS reset instructions from the manual. It worked just like it’s supposed to.

 

[R8er]

No battery light. am I crazy?

 

[R8er]

Disconnecting for 30 minutes didn’t change anything. Darn

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