DOCUMENTED DIAGNOSTIC CONTEXT

Diagnostic code articles — Page 24.

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.

Bank-2 secondary-air response and a catalog-label correction

distinguish the N112 electrical fault from a generic module label

N112 short-to-ground indication also warrants relay assessment

interpret the secondary-air valve's short-to-positive fault

Volkswagen secondary-air bank 1 low flow: distinguish air and vacuum paths

Volkswagen secondary-air bank 1 leak and the combination valve

The N80 purge-control circuit is shorted to ground

Volkswagen N80 purge-valve open circuit and the J17 relay check

Secondary-tank fuel level does not change as expected

Secondary fuel-level signal remains electrically low

Volkswagen secondary-air relay J299 open circuit

The secondary-air pump relay circuit is shorted to B+

Secondary-air pump relay control is shorted to ground

An electrical fault in the secondary-air pump relay circuit

Volkswagen EGR position adaptation and a failed basic setting

Maxima small-leak diagnosis uses positive tank pressure

the 2001 Altima uses this code for a very small EVAP leak

Subaru fuel-level performance problem 2

Ford purge-flow diagnosis changes with the EVAP application

Altima detects purge when the valve should be closed

Ford purge-flow sensor circuit fault versus inadequate purge flow

Altima vent restriction can imitate a valve stuck closed

Altima purge monitoring depends on throttle-state information

Altima vent does not seal when EVAP diagnosis requests it

DMTL reference-measurement current is too high

Ford fuel-tank vacuum does not recover as expected

Ford canister-vent solenoid voltage disagrees with its commanded state

DMTL switching-solenoid circuit high

An open secondary-air relay control path

Volkswagen G235 exhaust-temperature plausibility and the BBW note

Honda EVAP leakage on the fuel-tank side

Honda EVAP canister-side leak assessment

Volkswagen G236 exhaust-temperature sensor short to ground

Ford A/C relay primary control fails its electrical check

Ford historical A/C pressure input is above its voltage limit

Ford historical A/C pressure input is below its voltage limit

Ford A/C pressure does not change enough when the clutch engages

Ford A/C demand was active when self-test expected otherwise

Ford A/C clutch cycles too frequently for the control strategy

The leak-detection pump has an electrical circuit fault

Leak-detection pump V144 has a supply-side circuit fault

Leak-detection pump V144 circuit shorted to ground

Volkswagen leak-detection pump open circuit and canister sealing

Ford low-speed fan and hydraulic-fan systems use different P1474 tests

a leak-detection pump signal fault is not a proven EVAP leak

Volkswagen EVAP pump insufficient vacuum: test the supply separately

The evaporative leak-detection pump malfunctions

Ford high-speed cooling-fan relay control fails its electrical comparison

Subaru cooling-fan relay high input

a Wrangler EVAP restriction needs more than a leak check

Altima vacuum-cut bypass has an electrical control fault

Altima bypass performance depends on valves and vapor plumbing

high battery-temperature signal voltage on a Wrangler

separating a low temperature signal from a low battery

when the Wrangler leak-detection switch does not change

checking the Wrangler leak-detection-pump solenoid circuit

Honda EGR position-feedback voltage high

the Jeep hydraulic cooling-fan control circuit

Ford vehicle-speed interruptions interfere with other OBD tests

Ford detects vehicle-speed input during a stationary self-test

Ford speed-information error requests transmission-lamp indication

Volkswagen alternator DF load signal and the BEW measuring-value note

Ford idle-air control output has an electrical-load fault

Ford actual idle speed exceeds the requested speed

Ford actual idle speed stays below the requested speed

the upper idle-regulation limit can point toward restricted intake air

High idle and the idle-airflow response test

Subaru idle-air signal 1 low input

Subaru idle-air signal 1 high input

Subaru idle-air signal 2 low input

Subaru idle-air signal 2 high input

Airflow disagrees with the throttle-based estimate

Measured throttle position differs from the modeled position

Ford bank-one intake-runner input needs mechanical and feedback checks

Ford bank-two intake-runner monitor input is outside its expected range

Ford intake-runner feedback indicates an open position at closed throttle

Volkswagen bank 1 cam adjustment malfunction and N205 control

Lexus RX300 brake-switch signal remains applied

Volkswagen bank 2 cam adjustment: separate G163 feedback from N208 operation

VAG implausible crash signal and the older Audi hazard-switch splice