Inspection Procedure 4
INSPECTION PROCEDURE 4: Radiator Fan and Condenser Fan do not Change Speed or StopNOTE: if the engine coolant temperature reaches 110°C (230°F) or higher, the radiator fan control runs the radiator fan for up to 5 minutes even after the ignition switch is turned to the "LOCK" (OFF) position [the fan stops its rotation when the engine coolant temperature decreases to 110°C (230°F) or lower.]
2.4L ENGINE
Part 1 Of 2:
Part 2 Of 2:
[3.0L ENGINE]
CIRCUIT OPERATION
^ The fan controller is powered from fusible link number 2.
^ The ECM [M/T] or PCM [A/T] judges the required revolution speed of radiator fan motor and condenser fan motor using the input signals transmitted from A/C switch, automatic compressor controller, vehicle speed sensor and engine coolant temperature sensor. The ECM [M/T] or PCM [A/T] activates the fan controller to drive the radiator fan motor and condenser fan motor.
TECHNICAL DESCRIPTION
The fan controller has variable control of the radiator fan motor and the condenser fan motor speeds using signals transmitted from the ECM [M/T] or PCM [A/T].
TROUBLESHOOTING HINTS
^ Malfunction of fan control relay
^ Malfunction of fan controller
^ Malfunction of ECM [M/T] or PCM [A/T]
DIAGNOSIS
Required Special Tool:
^ MB991223: Harness Set
STEP 1. Check the fan control relay.
Q: Is the fan control relay in good condition?
YES: Go to Step 2.
NO: Replace the part, then go to Step 6.
STEP 2. Check the harness wire between fan control relay connector A-09X (terminal number 2) and fan controller connector A-30 (terminal number 3).
Q: Are the harness wire between fan control relay connector A-09X (terminal number 2) and fan controller connector A-30 (terminal number 3) damaged?
YES: Repair or replace the part, then go to Step 6.
NO: Go to Step 3.
STEP 3. Check the circuit at ECM connector C-49 (terminal number 21) <2.4L-M/T>, C-51 (terminal number 18) <3.0L-M/T> or PCM connector C-50 (terminal number 18) <2.4L-A/T>, C-52 (terminal number 18) <3.0L-A/T>.
1. Connect ECM connector C-49 (terminal number 21) <2.4L-M/T>, C-51 (terminal number 18) <3.0L-M/T> or PCM connector C-50 (terminal number 18) <2.4L-A/T>, C-52 (terminal number 18) <3.0L-A/T>.
2. Start the engine and run it at idle. [Engine coolant temperature: 80°C (176°F) or less]
3. Measure the voltage between terminal number 21 <2.4L-M/T> or 18 <2.4L-A/T, 3.0L> and ground.
Q: Is the voltage 0 - 0.3 volt when radiator fan is not operating?
YES: Go to Step 6.
NO: Go to Step 4.
STEP 4. Check the harness wire between ECM connector C-49 (terminal number 21) <2.4L-M/T>, C-51 (terminal number 18) <3.0L-M/T> or PCM connector C-50 (terminal number 18) <2.4L-A/T>, C-52 (terminal number 18) <3.0L-A/T> and fan controller connector A-30 (terminal number 2).
NOTE: If intermediate connector C-07 (terminal number 6) is damaged, repair or replace it.
Q: Are the harness wires between ECM connector C-49 (terminal number 21) <2.4L-M/T>, C-51 (terminal number 18) <3.0L-M/T> or PCM connector C-50 (terminal number 18) <2.4L-A/T>, C-52 (terminal number 18) <3.0L-A/T> and fan controller connector A-30 (terminal number 2) damaged?
YES: Repair or replace them, then go to Step 6.
NO: Go to Step 5.
STEP 5. Check the fan controller at ECM connector C-49 (terminal number 21) <2.4L-M/T>, C-51 (terminal number 18) <3.0L-M/T> or PCM connector C-50 (terminal number 18) <2.4L-A/T>, C-52 (terminal number 18) <3.0L-A/T>.
1. Disconnect ECM connector C-49 (terminal number 21) <2.4L-M/T>, C-51 (terminal number 18) <3.0L-M/T> or PCM connector C-50 (terminal number 18) <2.4L-A/T>, C-52 (terminal number 18) <3.0L-A/T>.
2. Pull out the terminal number <2.4L-M/T> or 18 <2.4L-A/T, 3.0L> and connect it to the body ground.
3. Reconnect ECM connector C-49 (terminal number 21) <2.4L-M/T>, C-51 (terminal number 18) <3.0L-M/T> or PCM connector C-50 (terminal number 18) <2.4L-A/T>, C-52 (terminal number 18) <3.0L-A/T> with pin 21 <2.4L-M/T> or 18 <2.4L-A/T, 3.0L> still removed.
4. Turn the ignition switch to the " ON" position.
Q: Do the radiator fan motor and condenser fan motor stop?
YES: Replace the ECM [M/T] or PCM [A/T]. Then go to Step 6.
NO: Replace the radiator fan motor and fan controller assembly. Then go to Step 6.
STEP 6. Check the symptoms.
Q: Do the radiator fan and condenser fan operate correctly?
YES: This diagnosis is complete.
NO: Return to Step 1.