P0507
DTC P0507 IDLE CONTROL SYSTEM - RPM HIGHER THAN EXPECTEDComponent Location:
GENERAL DESCRIPTION
The Idle Speed Control Actuator (ISCA) is installed on the intake manifold and controls the intake airflow that is bypassed around the throttle plate to keep constant engine speed when the throttle valve is closed. The function of the ISCA is to maintain idle speed according to various engine loads and conditions, and also to provide additional air during starting. The ISCA consists of an opening coil, a closing coil, and a permanent magnet. Based on information from various sensors, the PCM controls both coils by grounding their control circuits. According to the control signals from the PCM, the valve rotor rotates to control the by pass airflow into the engine.
DTC DESCRIPTION
The PCM monitors engine speed deviation from the target idle engine speed when the vehicle is stopped and the idle speed valve opening is stable.The PCM sets DTC P0506 if the difference to the target idle engine speed is lower than the predetermined threshold. If the same error code is set in the next driving cycle, the PCM illuminates the MIL.
DTC Detecting Condition:
Specification:
Schematic Diagram:
SIGNAL WAVEFORM & DATA
Using the channel 1, 2 of scan tool, it is the wave form at terminal 1, 3 of ISCA in idling.
1. 1 .The wave must be opposite to each other.
2. 2.The lower voltage must be below 1 V and the upper must be battery voltage.
The above waveforms are the voltage signals generated when ISCA operates. This ISCA type is duty type and the time ratio opened determines duty amount. The left side is the waveform of ISCA Opening coil during idle. The right side is the waveform of ISCA Closing coil during idle.
MONITOR DTC STATUS
This is the inspection procedure to determine whether it is present DTC or memoried one by monitoring the current signal or by using the function of oscilloscope with Hi-scan pro.
1. Connect scantool to Data Link Connector(DLC).
2. Warm up the engine to normal operating temperature.
3. Monitor the "ISC actuator duty" parameter on the scantool.
Service standard
A/CON switch OFF: 25 - 45%
A/CON switch ON : 35 - 55%
NOTE: The data shown above is only for reference and there may be a little difference actually
4. Is parameter displayed within specifications?
YES: Fault is intermittent caused by poor contact in the sensor's and/or PCM's connector or was repaired and PCM memory was not cleared.Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage. Repair or replace as necessary and then go to "Verification of Vehicle Repair" procedure.
NO: Go to "W/Harness Inspection" procedure.
TERMINAL & CONNECTOR INSPECTION
1. Many malfunctions in the electrical system are caused by poor harness and terminals. Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage.
2. Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage.
3. Has a problem been found?
YES: Repair as necessary and go to "Verification of vehicle Repair" procedure.
NO: Go to "Power Circuit inspection" procedure.
POWER CIRCUIT INSPECTION
The voltage check of ISCA, after disconnection of ISCA, is to check open or short in power supply line.
1. Ignition "OFF"
2. Disconnect ISCA connector.
3. Ignition "ON" & Engine "OFF"
4. Measure voltage between terminal 2 of sensor harness connector and chassis ground.
Specification : approximately B+
5. Is measure voltage within Specification?
YES: Go to "Control Circuit Inspection" procedure.
NO:
- Short circuit to chassis ground between ISCA harness connector and control relay.
- Open circuit between ISCA harness connector and control relay.
- Repair as necessary and go to "Verification Vehicle Repair" procedure.
NOTE:
1. In case,when ISCA connector is disconnected, the voltage of ISCA terminal 2 is 0 V.
2. ECM also sets P1505 and P1507 if it detects the open circuit in ISCA power line.
- Possible cause: Open or short circuit in battery power line after fuse, (15 A INJ).
CONTROL CIRCUIT INSPECTION
1. Check for open in harness
1. Ignition "OFF"
2. Disconnect ISCA connector.
3. Ignition "ON" & Engine "OFF"
4. Measure voltage between terminal 1, 3 of sensor harness connector and chassis ground.
Specification : approximately 3.6 V
5. Is measure voltage within Specification?
YES: Go to "Check for short to ground in harness" as below.
NO:
- Open or Short circuit to chassis ground between ISCA harness connector and PCM harness connector.
- Repair as necessary and go to "Verification Vehicle Repair" procedure.
2. Check for short to ground in harness
1. Ignition "OFF"
2. Disconnect ISCA connector and PCM connector.
3. Ignition "ON" & Engine "OFF"
4. Measure resistance between terminal 1, 3 of sensor harness connector and chassis ground.
Specification : infinite
5. Is measure resistance within Specification?
YES: Go to "Check for short between open coil and close coil harness as below.
NO:
- Short circuit to chassis ground between ISCA harness connector and PCM harness connector.
- Repair as necessary and go to "Verification Vehicle Repair procedure.
3. Check for short between open coil and close coil harness
1. Ignition "OFF"
2. Disconnect ISCA connector and PCM connector.
3. Ignition "ON" & Engine "OFF"
4. Measure resistance between terminal 1, 3 of sensor harness connector.
Specification : infinite
5. Is measure resistance within Specification?
YES: Go to "Component Inspection" procedure.
NO:
- Shorted circuit between ISCA open signal circuit and close signal circuit.
- Repair as necessary and go to "Verification Vehicle Repair" procedure.
COMPONENT INSPECTION
The purpose of measuring ISCA resistance is to find if the open circuit is in the component.
1. Check ISCA
1. Measure resistance between terminal 2 and 3 of sensor connector(To sensor side)
Specification: 20 °C(68 °F) :14.9 - 16.1 Ohms
2. Is measure resistance within Specification?
YES: Go to "Check for ISCA sticking " as below.
NO: Substitute with a known-good ISCA and check for proper operation. If the problem is corrected, replace ISCA and then go to "Verification of Vehicle Repair" procedure.
2. Check for ISCA sticking.
1. Ignition "OFF"
2. Check that ISCA actuator valve is clean and not sticking.
3. Check that throttle lever return spring is clean and sticking.
4. Check intake air system and vacuum hoses to intake air system.
5. Are the results of these checks OK?
YES: Substitute with a known-good PCM and check for proper operation. If the problem is corrected, replace PCM and then go to "Verification of Vehicle Repair� procedure.
NO: Substitute with a known-good ISCA and check for proper operation. If the problem is corrected, replace ISCA and then go to "Verification of Vehicle Repair" procedure.
VERIFICATION OF VEHICLE REPAIR
After a repair it is essential to verify that the fault has been corrected.
1. Monitor and record the Freeze Frame Data for the Diagnostic Trouble Code (DTC) which has been diagnosed.
2. Using a Scantool, Clear the DTCs.
3. Operate the vehicle within conditions noted in the freeze frame data or enable conditions
4. Monitor that all rediness test have been verified as "Complete"
5. Are any DTCs present?
YES: Go to the applicable troubleshooting procedure.
NO: System is performing to specification at this time.