Theory Of Operation

WARNING: This page is about a different car, the 2013 RAM 2500 HD and 2012 RAM Pickup. However, it is still accessible from the selected car via links, so may be relevant.

The Electronic Throttle Control (ETC) Motor is controlled by the Powertrain Control Module (PCM). The DC motor located in the throttle body drives the throttle blade. In order to decrease idle speed, along with spark and fuel delivery changes the PCM commands the throttle closed reducing air flow into the engine and the idle speed decreases. In order to increase idle speed, the PCM commands the throttle plate open allowing more air to pass the throttle plate.

With the engine running above 285 RPM and none of the following DTCs active; (TPS DTCs) P0121, P0122, P0123, P0221, P0222, P0223, P2135, (MAP DTCs) P0107, P0108, P0129, (5-Volt Supply DTCs) P0642, P0643, P0652, P0653, P1618, P1628, (CKP and CMP) P0016, P0335, P0339, P0340, P0344, and P2172, P2173. P2175.
Set Condition:
The Powertrain Control Module (PCM) calculated MAP value is greater than actual MAP value plus an offset value. One trip fault. Three good trips to turn of the mil. ETC light will flash.

Possible Causes
RESTRICTED AIR INLET SYSTEM
RESISTANCE IN THE 5-VOLT SUPPLY CIRCUIT
RESISTANCE IN THE 5-VOLT SUPPLY CIRCUIT
RESISTANCE IN THE MAP SENSOR SIGNAL CIRCUIT
RESISTANCE IN SENSOR GROUND CIRCUIT
RESISTANCE IN THE THROTTLE POSITION SENSOR SIGNAL CIRCUITS
RESISTANCE IN THE THROTTLE POSITION SENSOR RETURN CIRCUIT
MAP SENSOR
THROTTLE POSITION SENSOR
POWERTRAIN CONTROL MODULE (PCM)

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Refer to STANDARD PROCEDURE .