Test Description

WARNING: This page is about a different car, the 2004 Chevrolet Corvette. However, it is still accessible from the selected car via links, so may be relevant.

The number below refers to the step number on the diagnostic table.

2: This test determines whether the engine can achieve the commanded RPM. If the engine does not reach the commanded RPMs, the test determines whether the RPM is too high or too low.

DTC P0506

Step	Action	Yes	No
Schematic Reference: Engine Controls Schematics Connector End View Reference: Powertrain Control Module (PCM) Connector End Views and Engine Controls Connector End Views
1	Did you perform the Diagnostic System Check-Engine Controls?	Go to Step 2	Go to Diagnostic System Check - Engine Controls
2	Start the engine. Ensure the engine is at operating temperature. Command the engine speed to 1,500 RPM, then to 500 RPM, and back to 1,500 RPM with a scan tool. Exit the RPM control function. Does the engine speed correspond, within 100 RPM, with each command?	Go to Intermittent Conditions	Go to Step 3
3	Inspect for any condition that can reduce idle speed by increasing engine load. The following examples are possible conditions: Incorrect torque converter clutch (TCC) operation Accessories that require additional torque to operate Restricted exhaust Mechanical conditions that limit engine speed Did you complete the action?	Go to Step 4	-
4	Clear the DTCs with a scan tool. Turn OFF the ignition for 30 seconds. Start the engine. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/failure Records. Did the DTC fail this ignition?	Go to Step 2	Go to Step 5
5	IMPORTANT: Be aware that repairing 1 individual condition may correct more than 1 DTC. Observe the Capture Info with a scan tool.Are there any DTCs that have not been diagnosed?	Go to Diagnostic Trouble Code (DTC) List	System OK