Idle Speed Control Check. Cadillac DeVille 2000

For 1990-2009 cars only

Makes 🢒 Cadillac 🢒 2000 🢒 DeVille 🢒 Engine 🢒 Engine Controls - 4.6L 🢒 Idle Speed Control Check

Refer to Engine Controls Schematics,

MAF/IAT Sensor and IAC Valve

Engine Controls Components
Powertrain Control Module (PCM)
Cruise Control and Vehicle Speed Signal
EVAP Valves, EGR Valve
OBD II Symbol Description Notice
Power and Grounding Connector End Views Fuse Blocks and Ignition Switch
START Circuit Breaker, PCM IGN and IGN1 Fuses
START Circuit Breaker, PCM IGN and IGN1 Fuses
Powertrain Control Module Connector End Views
Handling ESD Sensitive Parts Notice
G100
.

Circuit Description

Refer to MAF/IAT Sensor and IAC Valve for an electrical diagram of this circuit.

The Idle Speed Control Check verifies proper IAC valve operation.

Diagnostic Aids

Reviewing the Failure Records may help diagnose an intermittent failure by showing how long ago and under what conditions a DTC has set.

Test Description

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

This check test the IAC valve to make sure that it is moving in and out without binding. When the IAC valve is commanded the PCM adjusts the IAC position and spark advance for a desired RPM.

Idle Speed Control Check

Step	Action	Values	Yes	No
1	Was the Powertrain On Board Diagnostic (OBD) System Check performed?	--	Go to Step 2	Go to Powertrain On Board Diagnostic (OBD) System Check
2	Connect the scan tool. Are any other DTCs set?	--	Go to the applicable DTC	Go to Step 3
3	Start and idle the engine. Turn all accessories Off. In Misc Tests, select IAC System. Command the engine speed up 1500 RPM, down to 500 RPM then back to 1500 RPM while monitoring the engine speed display. Does the engine speed remain within the specified value of desired idle for each RPM command? If the engine speed was lower then refer to DTC P0506 Idle Speed Low. If the Engine Speed was higher than refer to DTC P0507 Idle Speed High. Does the Engine Speed remain within the specified value of Desired Idle for each RPM command?	50 RPM	Fault not present	Go to Symptoms

Step

Action

Values

Yes

Was the Powertrain On Board Diagnostic (OBD) System Check performed?

Go to Step 2

Go to Powertrain On Board Diagnostic (OBD) System Check

Connect the scan tool.

Are any other DTCs set?

Go to the applicable DTC

Go to Step 3

Start and idle the engine.
Turn all accessories Off.
In Misc Tests, select IAC System.
Command the engine speed up 1500 RPM, down to 500 RPM then back to 1500 RPM while monitoring the engine speed display.
Does the engine speed remain within the specified value of desired idle for each RPM command?
If the engine speed was lower then refer to DTC P0506 Idle Speed Low.
If the Engine Speed was higher than refer to DTC P0507 Idle Speed High.

Does the Engine Speed remain within the specified value of Desired Idle for each RPM command?

50 RPM

Fault not present

Go to Symptoms