- Start engine an allow it to reach normal operating temperature. Using scan tool, actuate IAC motor to 1400 RPM. If engine speed is 1300-1500 RPM, stop actuation. IAC motor is operating properly. If engine speed is not 1300-1500 RPM, go to next step.
- Start engine and allow it to idle. Check engine, brake booster and vacuum hoses for leaks. Repair vacuum leaks as necessary. Perform TEST VER-2A. If no vacuum leaks exist, go to next step.
- Turn ignition off. Disconnect IAC motor connector. IAC motor is located on throttle body. Visually inspect connector for corroded, damaged, pushed-out or miswired terminals. Repair connector and terminals as necessary. Perform TEST VER-2A. If connector and terminals are okay, go to next step.
NOTE:
For connector terminal identification, see CONNECTOR IDENTIFICATION . For circuit identification and wiring diagram, see CHEROKEE
wiring diagram in WIRING DIAGRAMS article.
- Ensure ignition is off. Ensure IAC motor connector is still disconnected. Disconnect PCM connectors. PCM is located in engine compartment. See PCM LOCATION table under SYSTEM DIAGNOSTICS. Clean and/or repair connectors as necessary. Using an ohmmeter, check resistance between ground and PCM connector, IAC driver No. 1 circuit. If resistance is less than 5 ohms, repair driver No. 1 circuit for short to ground. Perform TEST VER-2A. If resistance is 5 ohms or more, go to next step.
- Ensure ignition is off. Ensure IAC motor and PCM connectors are still disconnected. Using ohmmeter, check resistance between ground and PCM connector, IAC driver No. 2 circuit. If resistance is less than 5 ohms, repair driver No. 2 circuit for short to ground. Perform TEST VER-2A. If resistance is 5 ohms or more, go to next step.
- Ensure ignition is off. Ensure IAC motor and PCM connectors are still disconnected. Using ohmmeter, check resistance between ground and PCM connector, IAC driver No. 3 circuit. If resistance is less than 5 ohms, repair driver No. 3 circuit for short to ground. Perform TEST VER-2A. If resistance is 5 ohms or more, go to next step.
- Ensure ignition is off. Ensure IAC motor and PCM connectors are still disconnected. Using ohmmeter, check resistance between ground and PCM connector, IAC driver No. 4 circuit. If resistance is less than 5 ohms, repair driver No. 4 circuit for short to ground. Perform TEST VER-2A. If resistance is 5 ohms or more, go to next step.
NOTE:
Voltage may switch or remain constant in this step.
- Ensure ignition is off. Ensure IAC motor connector is still disconnected. Reconnect PCM connectors. Turn ignition on, with engine off. Using scan tool in actuator tests mode, actuate IAC stepper motor. Using a voltmeter, check voltage on IAC motor connector, driver No. 1 circuit. If voltage is more than 5 volts at any time, go to next step. If voltage is not 5 volts or more at any time, perform appropriate DTC P0505: IAC MOTOR CIRCUIT test.
NOTE:
Voltage may switch or remain constant in this step.
- Ensure ignition is off. Ensure IAC motor connector is still disconnected. Ensure ignition is on, with engine off. Using scan tool in actuator tests mode, actuate IAC stepper motor. Using voltmeter, check voltage on IAC motor connector, driver No. 2 circuit. If voltage is more than 5 volts at any time, go to next step. If voltage is not 5 volts or more at any time, perform appropriate DTC P0505: IAC MOTOR CIRCUIT test.
NOTE:
Voltage may switch or remain constant in this step.
- Ensure ignition is off. Ensure IAC motor connector is still disconnected. Ensure ignition is on, with engine off. Using scan tool in actuator tests mode, actuate IAC stepper motor. Using voltmeter, check voltage on IAC motor connector, driver No. 3 circuit. If voltage is more than 5 volts at any time, go to next step. If voltage is not 5 volts or more at any time, perform appropriate DTC P0505: IAC MOTOR CIRCUIT test.
NOTE:
Voltage may switch or remain constant in this step.
- Ensure ignition is off. Ensure IAC motor connector is still disconnected. Ensure ignition is on, with engine off. Using scan tool in actuator tests mode, actuate IAC stepper motor. Using voltmeter, check voltage on IAC motor connector, driver No. 4 circuit. If voltage is more than 5 volts at any time, go to next step. If voltage is not 5 volts or more at any time, perform appropriate DTC P0505: IAC MOTOR CIRCUIT test.
- Turn ignition off. Disconnect PCM connectors. Visually inspect connectors for corroded, damaged, pushed-out or miswired terminals. Repair connectors and terminals as necessary. Perform TEST VER-2A. If connectors and terminals are okay, go to next step.
- Ensure ignition is off. Ensure IAC motor and PCM connectors are still disconnected. Using an ohmmeter, check resistance between IAC motor connector, driver No. 2 circuit, and driver No. 3 and driver No. 4 circuits. If resistance is 5 ohms or more between all circuits, go to next step. If resistance is less than 5 ohms between any 2 circuits, repair driver circuits that are shorted together. Perform TEST VER-2A.
- Ensure ignition is off. Ensure IAC motor and PCM connectors are still disconnected. Using ohmmeter, check resistance between IAC motor connector, driver No. 1 circuit and each remaining driver circuit. If resistance is 5 ohms or more between all circuits, go to next step. If resistance is less than 5 ohms between any 2 circuits, repair driver circuits that are shorted together. Perform TEST VER-2A.
- Ensure ignition is off. Ensure IAC motor and PCM connectors are still disconnected. Using ohmmeter, check resistance between IAC motor connector, driver No. 3 circuit (Brown/White wire) and driver No. 4 circuit (Violet/Black wire). If resistance is 5 ohms or more, go to next step. If resistance is less than 5 ohms, repair driver No. 3 circuit for short to driver No. 4 circuit. Perform TEST VER-2A.
- At this time, IAC motor is assumed to be defective. Replace IAC motor. Perform TEST VER-2A.