P085

DTC P085:

Throttle Body:

CIRCUIT DESCRIPTION
The Powertrain Control Module (PCM) continuously learns base idle position. This base idle position is the relationship of engine rpm to Throttle Position (TP). The PCM is limited to a fixed amount of learned throttle angle that it can apply. When this limit is reached, Code P085 will set. The cause of this increase in learned throttle angle is usually deposits in the throttle body.

TEST CONDITIONS
Test continuously.

FAILURE CONDITIONS
1. A/C "OFF," learned idle throttle angle 3.9 degrees or greater.
OR
2. A/C "ON," learned idle throttle angle 3.9 degrees or greater.

ACTION TAKEN
PCM turns "ON" the Malfunction Indicator Lamp (MIL) (Service Engine Soon).

NOTES ON FAULT TREE
1. Checking for other throttle position sensor codes being set that can cause other throttle body problems.
2. Checking if throttle body deposits are causing the increase in the learned throttle angle. Also, a loose fitting air leaner or air intake duct may allow debris to enter the throttle body.
3. Checking if Idle Speed Control (ISC) motor can retract far enough to close the throttle position switch.
4. Checking for proper operation of the ISC.

NOTES ON INTERMITTENTS
Code P085 may set due to an engine overheated condition in which the PCM will only allow the engine to run on four cylinders, causing a high idle throttle angle. If this occurs, clear Code P085, reset Idle Learn using PCM override PS13 and perform TP Sensor/Idle Learn.