P0B98: Hybrid/EV Battery Voltage Sense S Circuit High

P0B98 marks a sense S value that is too high to be a cell voltage. The thresholds vary with the battery chemistry and controller: GM's 2016 Volt and 2019 battery controllers flag 4.8 V or more after 1.4 s in 2 s (Type A), the 16OBDG02 programme 4.90 V in 14 of 18 samples (Type A), and the eAssist mild hybrid more than 4.65 V in 7 of 10 samples with the 12 V supply above 8.8 V (Type B). On the 2012 two-mode trucks S is NiMH block 19 and its limit is 23 V, 15 of 20 samples, Type B. Like the low test, the high test waits until open sense line faults are ruled out. The fix is usually wiring or the monitoring board; a truly overcharged cell is rare but must be excluded.

Symptoms

• MIL and service hybrid system message
• Charging and regeneration limited

Most likely causes

• Sense lead S shorted to a higher cell or busbar
• Measuring chip reading channel S incorrectly
• Real overvoltage of the cell or block on channel S

What to check, in order

Start with the simplest. You can tick off each step.

1. Read the codes with a hybrid-compatible scanner and write down the freeze frame data
2. Check the sensor's ground and make sure the signal wire is not receiving voltage from another circuit.
3. Make sure the battery cooling air intake is clean
4. Check the 12 V auxiliary battery, which can also trigger warnings
5. Leave any high-voltage measurements to a specialized repair shop

Good to know

• It can trigger limp mode.
• It affects emissions.

What each character of P0B98 means

• P: Powertrain: engine and transmission
• 0: Generic code: same on every make
• B: Subsystem depends on the code range
• 98: Specific fault in that system

Frequently asked questions

Can I keep driving with code P0B98?

If the car still runs, drive as little as possible and go to a specialized repair shop. Do not touch the orange cables: they carry high voltage.

What causes code P0B98?

The most common causes are: sense lead S shorted to a higher cell or busbar; measuring chip reading channel S incorrectly; real overvoltage of the cell or block on channel S.

Related codes

• P0B95Hybrid/EV Battery Voltage Sense S Circuit
• P0B96Hybrid/EV Battery Voltage Sense S Circuit Range/Performance
• P0B97Hybrid/EV Battery Voltage Sense S Circuit Low
• P0B99Hybrid/EV Battery Voltage Sense S Circuit Intermittent/Erratic
• P0B93Hybrid/EV Battery Voltage Sense R Circuit High
• P0B9DHybrid/EV Battery Voltage Sense T Circuit High

Sources

• gsi.ext.gm.com: 16OBDG01 Hybrid Diagnostics
• gsi.ext.gm.com: 16OBDG02 Hybrid Diagnostics
• gsi.ext.gm.com: 13OBDG05C Hybrid Diagnostics
• gsi.ext.gm.com: 12OBDG06 Hybrid Diagnostics

Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.