DTC P0069 – Manifold Absolute Pressure (MAP) – Barometric Pressure (BARO) Sensor Correlation

🚗 P0069 — MAP/BARO Pressure Correlation Fault

This code appears when the MAP sensor reading does not match the BARO (barometric) sensor reading under conditions where they should be close (usually at key-on, engine off).

🔧 Common Causes

🎀1. MAP sensor issues

Sensor internal fault

Sensor clogged with carbon/oil

Faulty MAP wiring (voltage, ground, signal)

🎀2. BARO sensor issues

(Separate sensor or built into the MAF sensor on many cars)

Faulty BARO sensor

Faulty MAF sensor (if BARO is built into MAF)

🎀3. Vacuum-related issues

Vacuum leak (intake hose, PCV, brake booster hose, manifold gasket)

MAP sensor hose cracked or disconnected (for vacuum-type MAP sensors)

🎀4. Electrical issues

Loose connectors

Corroded pins

Short/open in wiring harness

Low battery or unstable charging system

🎀5. ECM fault (rare)

🧰 Step-by-Step Diagnostic Procedure

Step 1 — Check live data

Using OBD scanner:

KOEO (Key On Engine Off):

MAP ≈ BARO ≈ atmospheric pressure (~101 kPa)

If MAP is much lower → MAP sensor issue

If BARO is incorrect → BARO/MAF sensor issue

Engine idling:

MAP should drop to ~25–40 kPa

BARO stays at ~101 kPa

Step 2 — Inspect MAP sensor

Unplug connector → check for corrosion or bent pins

Remove sensor → check for oil contamination or soot

Clean with sensor-safe cleaner (NO carb cleaner)

Test Voltage (Typical values):

5V reference → 4.8–5.0V

Ground → <0.1V

Signal:

KOEO: ~4.0–4.5V

Idle: ~1.0–1.5V

Step 3 — Check vacuum leaks

Inspect:

Intake pipe

Manifold gasket

PCV valve/pipe

Brake booster hose

Turbo hoses (if turbo car)

Spray brake cleaner around suspect areas → idle change = leak.

Step 4 — Check BARO/MAF sensor

If BARO is integrated into the MAF:

Check MAF readings

Check air filter and duct

Ensure no air leaks before the MAF

Clean MAF with MAF cleaner only

Step 5 — Sensor hose (if applicable)

Some vehicles (old Hyundai, Suzuki, Tata diesels) use hoses.

Check for:

Cracked hose

Soft/melted hose

Blocked hose (oil)

Replace if bad.

Step 6 — Wiring Continuity Test

Check MAP signal wire to ECM:

Resistance should be <1 Ω

No short to ground or short to 5V

Step 7 — Clear code and test drive

🛠 Common Fixes

Clean or replace MAP sensor

Replace MAF (if BARO built-in)

Fix vacuum leak

Replace MAP hose

Repair wiring

Replace BARO sensor (if separate)

Welcome To Madurai Car Service 💐🙏.