P0505

TROUBLESHOOTING PROCEDURES





CIRCUIT DIAGRAM





INSPECTION USING SCAN TOOL








HARNESS INSPECTION PROCEDURE

COMPONENT TEST PROCEDURE

Operation Sound Check

1. Check for the sound of the stepper motor after the ignition is switch ON (but without starting the motor).
2. If the operation sound cannot be heard, check the stepper motor's circuit.
3. If the circuit is normal, the problem may be the stepper motor or the ECM





Resistance Measurement between terminals
Measure the resistance between the respective terminals

Standard value:
Terminals 2-3 and 1: 28 - 33 Ohms at 20°C (68°F)
Terminals 5-4 and 6: 28 - 33 Ohms at 20°C (68°F)

Operation Check
Apply voltage as follows and check whether or not stepper motor movement occurs.





1. Connect the power supply (approximately 6 Volts) terminal (+) to terminals 2 and 5 of the connector.
2. Connect the power supply (-) terminal to terminals 3 and 4
3. Connect the power supply (-) terminal to terminals 3 and 4
4. Connect the power supply (-) terminal to terminals 3 and 6
5. Connect the power supply (-) terminal to terminals 1 and 6
6. Connect the power supply (-) terminal to terminals 1 and 4.
- Repeat the tests in sequence from (6) to (1) if vibration is detected, the stepper motor can be considered to be normal

TROUBLESHOOTING HINTS
1. If the stepper motor step increases to 100-120 steps or decreases to 0 steps, check for faulty stepper motor or open circuit in the harness.
2. It the idle speed control motor is normal but the stepper motor steps are out of specification, check the following:
- Poorly adjusted reference idle speed
- Deposit on the throttle valve
- Air leaking into the intake manifold through gasket gap Loose EGR valve seat
- Poor combustion in the cylinder (faulty ignition plug, ignition coil injector, low compression pressure, etc.)