DOCUMENTED DIAGNOSTIC CONTEXT

Diagnostic code articles — Page 28.

Understand what the recorded fault means, which findings change the diagnosis, and what the cited documentation can confirm. Each article states the system or vehicle scope it covers.

Some sources leave details unresolved. Those articles include a visible source note; a code match alone does not establish applicability to your vehicle.

Post-catalyst fuel correction reaches the lean limit

Post-catalyst fuel correction reaches the rich limit

Post-catalyst lean wording and the bank 2 upstream-sensor offset check

Bank 2 rich post-catalyst trim as an upstream lambda-offset diagnosis

Ram DEF-tank heater performance warning and DCU software

reductant purge-driver feedback is wrong while commanded off

reductant pressure-reduction performance needs its own test state

low purge-valve feedback is evaluated with the driver off

purge-driver feedback remains high during the on command

metering-unit heater conductance is checked during heating

the metering-unit heater's low-conductance start check

high metering-heater conductance is not high tank temperature

How the first DEF tank heater is checked for an open circuit

When DEF tank heater power or calculated resistance misses its target

heater 1 ground-short classification uses an off-state test

Understanding a high-circuit failure on DEF tank heater 1

Why an open DEF line-heater circuit is distinct from a tank-heater fault

line-heater performance checks resistance and delivered power

Reading a DEF line-heater low-circuit diagnosis correctly

A DEF line-heater short-to-power report and its diagnostic shutdown

heater C maps to the second tank heater in this system

Checking the second DEF tank heater’s resistance and power performance

Locating the meaning of a low circuit on the second DEF tank heater

heater 3 short-to-power is confirmed with heating switched off

The exhaust fuel injector’s open check uses different driver states

aftertreatment injector performance is judged through exhaust heat

A low aftertreatment-injector circuit result has separate recovery logic

A high exhaust injector circuit can be reported through on-state overcurrent

Volkswagen CJAA aftertreatment fuel-control deviation

exhaust temperature sensors are compared after a long soak

particulate-filter temperature correlation uses startup references

When DEF pressure fails to follow the commanded setpoint

reductant pressure exceeds its current target

SCR efficiency is a filtered model-based judgment

swirl-flap position does not track a settled command

first DEF injector needs excessive delivery compensation

reductant-controller performance includes memory and calibration checks

Why a throttle motor circuit-open code can include driver overheating

Throttle position differs from its modeled response

throttle motor driver reports a short-to-ground condition

throttle driver short-to-power differs from a position error

Mazda diesel idle-control diagnosis includes boost and vacuum faults

throttle shutdown-path monitoring refers to the previous cycle

limited power is a throttle-system response, not a single-part diagnosis

Throttle processor communication is distinct from a plate stuck in position

throttle module performance covers internal integrity tests

Learned throttle minimum position outside the permitted window

The bank 2 throttle circuit code has separate open-load and thermal paths

Throttle tracking error with a tolerance that changes as the command moves

Ram forced RPM limitation with throttle icing

A stuck-open throttle result is a command-response diagnosis

A stuck-closed throttle code needs the original control context

Throttle motor current performance is different from plate position error

Throttle does not return to its de-energized default position

Identify throttle B before interpreting a stuck-open report

A stuck-closed throttle B result is a control-state finding

Motor-current performance is different from throttle position error

The bank 2 throttle spring check examines several return behaviors

APP1 disagrees across primary and secondary processor evaluations

pedal channel one has a separate rationality classification

Accelerator pedal sensor 1 signal below its allowed range

Accelerator pedal sensor 1 signal exceeds the reference-scale limit

F-150 intermittent pedal faults and harness routing at the booster

APP2 is out of range on the secondary processor only

pedal channel two has an unresolved range classification

Accelerator pedal sensor 2 has a low or open signal

Accelerator pedal sensor 2 exceeds its electrical upper limit

When throttle-position information disagrees with the airflow model

The low-voltage limit for the second bank 2 throttle-position channel

A high signal on throttle-position sensor 2 at bank 2

Ford 6.0L pedal sensor F circuit voltage is low

the VAG high-signal fault can involve oxygen-sensor damage

Throttle position channels disagree after normalization

Accelerator pedal channels no longer agree

Low-pressure EGR motor needs excessive control duty

Fuel-pump shutdown following an accident message

The injector group A supply diagnosis includes short-circuit behavior

Injector 1 high-side circuit indicates a short to ground

Injector 1 remains electrically high when its driver is off

Reading injector group B supply faults through driver state