What is CAT Code 3002-12 & How to Solve It?

What is CAT Code 3002-12:

CAT Code 3002-12 signals an intake manifold pressure sensor fault — typically an electrical short or incorrect voltage input.

This sensor helps manage turbo boost and air/fuel ratios, so incorrect readings can cause rough engine performance or derates.

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Why This Happens

• Sensor wiring shorted to ground or battery.
• Sensor failing internally.
• Connector pins loose, bent, or wet.
• ECM interpreting bad signal from failed sensor.

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How to Fix It

1. Inspect the intake pressure sensor and harness.
2. Test for proper signal voltage (5V ref, ground, signal).
3. Replace the sensor if readings are unstable.
4. Repair connector damage or replace harness section.
5. Clear the code and retest boost and engine response.

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How to Avoid It Before It Happens

1. Replace MAP sensors during turbo inspections.
2. Protect wiring from chafing or oil damage.
3. Clean and reseat sensor connections during PM.
4. Track boost data over time for early failure signs.

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