Map sensor issue, wiring?

scotty305 · 05-05-2008, 09:23 PM

It sounds like something may be shorted to one of your MAP sensor wires. What is the history of the car and wiring harness? When was the last time everything worked correctly, and what have you changed since then? It could be something as simple as a pinched or pulled harness from working in the engine bay.

The MAP sensor voltage is pin 1O on the ECU (should read about 2.38-2.78V at atmospheric pressure when the engine is not running, and about 1.2-1.5V when idling), ground for the MAP sensor is pin 4D on the ECU, and the +5V reference power is pin 3I on the ECU. Try measuring these pins on the ECU (poke the back of the ECU connector with a paper clip to get a reading) and see if the ECU matches the MAP sensor when they are both plugged in.

edit: congrats! What was the problem?

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05-05-2008, 09:23 PM	#3
scotty305 Rotary Fan in Training Join Date: Mar 2008 Location: Culver City, CA Posts: 84 Rep Power: 18	It sounds like something may be shorted to one of your MAP sensor wires. What is the history of the car and wiring harness? When was the last time everything worked correctly, and what have you changed since then? It could be something as simple as a pinched or pulled harness from working in the engine bay. The MAP sensor voltage is pin 1O on the ECU (should read about 2.38-2.78V at atmospheric pressure when the engine is not running, and about 1.2-1.5V when idling), ground for the MAP sensor is pin 4D on the ECU, and the +5V reference power is pin 3I on the ECU. Try measuring these pins on the ECU (poke the back of the ECU connector with a paper clip to get a reading) and see if the ECU matches the MAP sensor when they are both plugged in. edit: congrats! What was the problem?