Pressure sensors — MAP, rail and A/C

CORE TEACHING Typical analogue voltage range; reference/signal; offset; plausibility; atmospheric reference; mechanical vs electrical pressure. PRACTICAL DEMONSTRATIONS AND TESTS KOEO MAP comparison with barometric pressure; fuel rail commanded vs actual; A/C pressure sensor signal. ADVANCED / SCAN TOOL LAYER Scope pressure pulsations/transients where useful; graph desired vs actual scan data. KEY DIAGNOSTIC QUESTIONS Does reading make physical sense before engine starts? Does it respond smoothly? Does an independent gauge agree? MUST-COVER CHECKPOINTS Identify sensor technology; supply/ground if applicable; expected signal type; physical stimulus; scan comparison; scope if time-varying; wiring-to-ECU proof.

A pressure sensor reads something believable but wrong enough to ruin the diagnosis.

Builds on

Lesson 22: Inductive sensors and AC signals

Feeds into

Lesson 24: Temperature sensors in real diagnosis

1. 18Power, ground and signal — the universal sensor pattern
2. 19Testing a three-wire sensor
3. 20Two-wire temperature and resistive sensors
4. 21Hall-effect cam and crank sensors
5. 22Inductive sensors and AC signals
6. 23Pressure sensors — MAP, rail and A/C
7. 24Temperature sensors in real diagnosis
8. 25Position sensors and plausibility
9. 26Testing actuators: motors, solenoids and valves