P CODE FAMILY

Powertrain code references — Page 29.

Engine, transmission and powertrain diagnostic references. Exact vehicle and module context still matters.

Generic OBD-II

P0B77

These are code references, not a list of confirmed faults on every vehicle. Read the source and applicability notes, then match the exact vehicle, year, engine and scan report.

sense-M fault needs the exact pack channel map

block 13 plausibility involves block 14 and pack voltage

block 13 low sensing should be checked as a paired event

block 13 high-voltage sensing needs repeated evidence

Hybrid/EV Battery Voltage Sense M Circuit Intermittent/Erratic

sense-N verification must show a valid completed monitor

block 14 rationality extends across two source pages

block 14 low sensing includes the block 15 report

the block 14 high branch is a direct range check

Hybrid/EV Battery Voltage Sense N Circuit Intermittent/Erratic

sense-O readings must be distinguished from actual cell voltage

block 15 plausibility relies on neighboring and total-pack data

block 15 low requires evidence from block 16 as well

a high block 15 report needs the correct monitor context

Hybrid/EV Battery Voltage Sense O Circuit Intermittent/Erratic

Voltage-sense P and the open-line pattern

block 16 rationality requires valid supporting measurements

block 16 low sensing is a neighboring-channel event

block 16 high is a repeated range finding

Hybrid/EV Battery Voltage Sense P Circuit Intermittent/Erratic

Sense Q requires context from the measuring electronics

block 17 plausibility requires a block 18 comparison

block 17 low sensing needs the neighboring reading

block 17 high sensing is not a battery replacement verdict

Hybrid/EV Battery Voltage Sense Q Circuit Intermittent/Erratic

Voltage sense R is checked under balancing load

block 18 rationality compares both late-pack channels

block 18 low depends on the block 19 report too

block 18 high has a separate threshold from performance faults

Hybrid/EV Battery Voltage Sense R Circuit Intermittent/Erratic

Sense S is an electrical-pattern diagnosis

block 19 plausibility reaches the final block measurement

the block 19 low code uses the final neighboring block

block 19 high sensing requires an eligible filtered event

Hybrid/EV Battery Voltage Sense S Circuit Intermittent/Erratic

Sense T and groups of zero battery readings

the final block rationality rule has no extra neighboring channel

block 20 low sensing does not require another block

block 20 high is distinct from total-pack overvoltage

Hybrid/EV Battery Voltage Sense T Circuit Intermittent/Erratic

Sense U open-line evidence is separate from range faults

Block 21 must agree with the pack comparison

Block 21 low logic also observes its neighbor

Block 21 high voltage is a qualified sensor report

Hybrid/EV Battery Voltage Sense U Circuit Intermittent/Erratic

Sense V and the limits of an open-circuit conclusion

Block 22 rationality depends on valid pack sensing

Block 22 low logic includes the adjacent block

Block 22 high reporting needs a sustained record

Hybrid/EV Battery Voltage Sense V Circuit Intermittent/Erratic

Sense W open-line checks depend on surrounding values

Sense W must move with the other cell readings

Sense W low is qualified separately from an open line

Sense W high requires valid measuring communication

Hybrid/EV Battery Voltage Sense W Circuit Intermittent/Erratic

Sense X open-line diagnosis uses relationships

Sense X performance follows voltage movement

Sense X low needs both timing and valid prerequisites

Sense X high is a timed upper-limit report

Hybrid/EV Battery Voltage Sense X Circuit Intermittent/Erratic

Sense Y requires an open-line pattern assessment

Sense Y performance is about direction of change

Sense Y low should not be read as a capacity measurement

Sense Y high and the meaning of a qualified event

Hybrid/EV Battery Voltage Sense Y Circuit Intermittent/Erratic

Sense Z open-line evidence includes common power paths

Sense Z must follow a changing voltage reference

Sense Z low is distinct from the open-sensing diagnosis

Sense Z high needs a valid two-second observation

Hybrid/EV Battery Voltage Sense Z Circuit Intermittent/Erratic

neighboring battery-block deviation is measured under load conditions

Jeep 4xe battery-voltage variation and the XU1 repair case

Hybrid/EV Battery Pack Cooling Fan Supply Voltage Circuit/Open

Hybrid/EV Battery Pack Cooling Fan Supply Voltage Circuit Low

fan feedback remains high when the battery fan is commanded off

Hybrid/EV Battery Temperature Sensor E Circuit

Sensor E is compared with other battery temperatures

Sensor E circuit low can correspond to a hot reported value

Sensor E circuit high can look extremely cold

Battery temperature sensor E fails a stability check