Diagnostic Test

1) DTC IS ACTIVE
Turn the ignition on.

With the scan tool, Clear DTCs in the Powertrain Control Module (PCM).

With the scan tool, actuate the Radiator Cooling Fan PWM Control State.

With the scan tool, select View DTCs.

Is the status Active for this DTC?

Yes
1. Go to 2).
No
1. Refer to *CHECKING FOR AN INTERMITTENT DTC .
2) (K173) RAD FAN RELAY CONTROL CIRCUIT SHORTED TO GROUND

Fig 1: Measuring The Resistance Between Ground And The RAD Fan Relay Control Circuit In The Radiator Fan Control Relay Connector
Courtesy of CHRYSLER LLC

Turn the ignition off.

Disconnect the Radiator Fan Control Relay.

Disconnect the Powertrain Control Module (PCM) connector.

Measure the resistance between ground and the (K173) RAD Fan Relay Control circuit in the Radiator Fan Control Relay connector.

Is the resistance above 100 ohms?

Yes
1. Go to 3).
No
1. Repair the (K173) RAD Fan Relay Control circuit for a short to ground.
2. Perform PCM VERIFICATION TEST .
3) (K173) RAD FAN RELAY CONTROL CIRCUIT OPEN OR HIGH RESISTANCE

Fig 2: Measuring The Resistance Of The RAD Fan Relay Control Circuit Between The Radiator Fan Control Relay Connector And The Appropriate Terminal Of Special Tool #8815
Courtesy of CHRYSLER LLC

CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals, resulting in poor terminal to pin connection. Install Miller Special Tool #8815 to perform diagnosis.

Measure the resistance of the (K173) RAD Fan Relay Control circuit between the Radiator Fan Control Relay connector and the appropriate terminal of special tool #8815.

Is the resistance below 5.0 ohms?

Yes
1. Go to 4).
No
1. Repair the (K173) RAD Fan Relay Control circuit for an open circuit or high resistance.
2. Perform PCM VERIFICATION TEST .
4) (Z723) GROUND CIRCUIT OPEN OR HIGH RESISTANCE

Fig 3: Radiator Fan Control Relay Connector - Pin 3
Courtesy of CHRYSLER LLC

Using a 12 volt test light connected to 12 volts, check the (Z723) Ground circuit in the Radiator Fan Control Relay connector.

NOTE: The test light should be illuminated and bright. Compare the brightness to that of a direct connection to the battery.

Is the test light illuminated and bright?

Yes
1. Go to 5).
No
1. Repair the (Z723) Ground circuit for an open circuit or high resistance.
2. Perform PCM VERIFICATION TEST .
5) RADIATOR FAN CONTROL RELAY

Fig 4: Radiator Fan Control Relay Connector - Pin 4
Courtesy of CHRYSLER LLC

Connect the Powertrain Control Module (PCM) connector.

Turn the ignition on.

With the scan tool, actuate the Radiator Cooling Fan PWM Control State.

Using a 12 volt test light connected to ground, check the (K173) RAD Fan Relay Control circuit in the Radiator Fan Control Relay connector.

NOTE: The voltage supplied to the solenoid circuit during the actuation will be less than battery voltage. The test light should be illuminated, but not as bright as a direct connection to the battery.

Is the test light illuminated during the actuation?

Yes
1. Replace the Radiator Fan Control Relay in accordance with the Service Information.
2. Perform PCM VERIFICATION TEST .
No
1. Go to 6).
6) POWERTRAIN CONTROL MODULE (PCM)
Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Radiator Fan Control Relay and the Powertrain Control Module (PCM).

Look for any chafed, pierced, pinched, or partially broken wires.

Look for broken, bent, pushed out or corroded terminals.

Refer to any Technical Service Bulletins that may apply.

Were any problems found?

Yes
1. Repair as necessary.
2. Perform PCM VERIFICATION TEST .
No
1. Replace and program the Powertrain Control Module (PCM) in accordance with the Service Information.
2. Perform PCM VERIFICATION TEST .