Diagnostic Test

1) LOW COOLANT SWITCH
NOTE: Perform the Instrument Cluster Self Test before proceeding with this test. If the Indicator does not illuminate, replace the Cluster.

Turn the ignition off.

Disconnect the Low Coolant Switch harness connector.

Connect a jumper wire between cavity 1 and cavity 2.

Turn the ignition on and wait approximately 1 minute.

With the scan tool in Inputs/Outputs, read the Low Coolant Switch state.

Does the scan tool display: Closed?

Yes
1. Replace the Low Coolant Switch in accordance with the Service Information.
2. Perform BODY VERIFICATION TEST .
No
1. Go To step 2).
2) (Z939) LOW COOLANT SWITCH GROUND CIRCUIT OPEN

Fig 1: Measuring Resistance Between Ground And Low Coolant Switch Ground Circuit
Courtesy of CHRYSLER LLC

Turn the ignition off.

Disconnect the Low Coolant Switch harness connector.

Measure the resistance between ground and the (Z939) Low Coolant Switch Ground circuit.

Is the resistance above 5.0 ohms?

Yes
1. Repair the (Z939) Low Coolant Switch Ground circuit for an open.
2. Perform BODY VERIFICATION TEST .
No
1. Go To step 3).
3) (G18) LOW COOLANT FLUID LEVEL SENSE CIRCUIT OPEN

Fig 2: Measuring Resistance Of Low Coolant Fluid Level Sense Circuit
Courtesy of CHRYSLER LLC

Turn the ignition off.

Disconnect the Low Coolant Switch harness connector.

Disconnect the Instrument Cluster harness connector.

Measure the resistance of the (G18) Low Coolant Fluid Level Sense circuit.

Is the resistance above 5.0 ohms?

Yes
1. Repair the (G18) Low Coolant Fluid Level Sense circuit for an open.
2. Perform BODY VERIFICATION TEST .
No
1. Replace and configure the Instrument Cluster in accordance with the Service Information.
2. Perform BODY VERIFICATION TEST .