What does a pick up coil do on 1990 dodge truck?

In a 1990 Dodge truck, the pickup coil (also sometimes called a crankshaft position sensor or CMP sensor) is a crucial component of the ignition system. Its primary function is to detect the position of the crankshaft. More specifically, it senses the passage of a reluctor wheel (a metal wheel with teeth) attached to the crankshaft.

This information is sent to the engine control module (ECM). The ECM uses this signal to:

* Determine the timing for ignition spark. It knows precisely when each cylinder is at top dead center (TDC) or close to it, allowing for accurate spark delivery.

* Control fuel injection. Accurate crankshaft position is essential for precise fuel injection timing.

* Monitor engine speed. The frequency of the pulses from the pickup coil directly relates to engine RPM.

A malfunctioning pickup coil can lead to a variety of problems, including:

* No start: The engine won't crank or start at all.

* Misfires: The engine will run rough, possibly with a miss in one or more cylinders.

* Stalling: The engine may stall unexpectedly.

* Poor performance: The engine may lack power or hesitate during acceleration.

* Check engine light: The vehicle's diagnostic system will likely illuminate the check engine light, storing a diagnostic trouble code (DTC) related to the crankshaft position sensor.

The location of the pickup coil varies slightly depending on the specific engine in your 1990 Dodge truck, but it's usually located near the crankshaft or the distributor (if equipped).