P1673

DTC P1673





Step 1 - 5





Step 6 - 13

Circuit Description
Ignition 1 voltage is supplied from the fuse block to the Instrument Cluster (IPC) by the ignition 1 voltage circuit. The Powertrain Control Module (PCM) controls the hot coolant indicator by grounding the hot coolant indicator control circuit via the underhood accessory wiring junction block. The PCM has an internal solid state device called a driver. The primary function of the driver is to supply the ground for the component being controlled. Each driver has a fault line which is monitored by the PCM. When the PCM is commanding a component ON, the voltage potential of the control circuit should be low (near 0 volts). When the PCM is commanding the control circuit to a component OFF, the voltage potential of the circuit should be high (near battery voltage). If the fault detection circuit senses a voltage other than what is expected, the DTC will set. The PCM will monitor the control circuit for the following:
- A short to ground
- A short to voltage
- An open circuit

Conditions for Running the DTC
- The ignition is ON.
- The system voltage is between 9 and 18 volts.

Conditions for Setting the DTC
- An improper voltage level has been detected on the hot coolant indicator control circuit.
- The condition is present for at least 30 seconds.

Action Taken When the DTC Sets
- The PCM will not illuminate the Malfunction Indicator Lamp (MIL).
- The PCM will store conditions which were present when the DTC set as Failure Records data only. This information will not be stored as Freeze Frame data.

Conditions for Clearing the MIL/DTC
- A History DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.
- The DTC can be cleared by using a scan tool.

Diagnostic Aids
If the condition is not present, refer to Testing for Intermittent and Poor Connections.

Test Description
The number(s) below refer to the step number(s) on the diagnostic table.
3. Tests for voltage at the ignition 1 voltage circuit of the hot coolant indicator. The Instrument Cluster fuse supplies ignition 1 voltage to the hot coolant indicator.
4. Verifies that the PCM is providing ground to the hot coolant indicator.
5. Tests if ground is constantly being applied to the hot coolant indicator.
12. The replacement PCM must be programmed.