P0693
DTC P0480, P0481, P0691, P0692, P0693, or P0694Circuit Description
Battery positive voltage is supplied to the cooling fan 1 relay from the COOL FAN #1 fuse. The Powertrain Control Module (PCM) or Engine Control Module (ECM) controls the cooling fan 1 relay by grounding the low speed cooling fan relay control circuit via an internal solid state device called a driver.
Battery positive voltage is supplied to the cooling fan 2 relay and the cooling fan 3 or S/P relay from the COOL FAN #2 fuse. The PCM/ECM controls the relays by grounding the high speed cooling fan relay control circuit.
When the PCM/ECM is commanding a relay on, the voltage potential of the control circuit should be low, near 0 volts. When the PCM/ECM is commanding the control circuit to a relay, 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/ECM will monitor the control circuit for the following:
^ A short to ground
^ A short to voltage
^ An open circuit
^ An open relay coil
^ An internally shorted or excessively low resistance relay coil
When the PCM/ECM detects any of the above conditions, the DTC will set and the affected driver will be disabled.
DTC Descriptors
This diagnostic procedure supports the following DTCs:
^ DTC P0480 Cooling Fan 1 Relay Control Circuit
^ DTC P0481 Cooling Fan 2 and 3 or S/P Relay Control Circuit
^ DTC P0691 Cooling Fan 1 relay Control Circuit Low Voltage
^ DTC P0692 Cooling Fan 1 Relay Control Circuit High Voltage
^ DTC P0693 Cooling Fan 2 and 3 or S/P Relay Control Circuit Low Voltage
^ DTC P0694 Cooling Fan 2 and 3 or S/P Relay Control Circuit High Voltage
Conditions for Running the DTC
^ The ignition is ON.
^ System voltage is between 9 - 18 volts.
^ The relay control circuit is transitioned from OFF to ON or ON to OFF.
Conditions for Setting the DTC
^ The PCM/ECM detects an open, a short to ground or a short to voltage on the cooling fan relay control circuit.
^ The above conditions are present for at least 30 seconds.
Action Taken When the DTC Sets
^ The PCM/ECM will illuminate the Malfunction Indicator Lamp (MIL) during the second consecutive trip in which the diagnostic test has been run and failed.
^ The PCM/ECM will store conditions which were present when the DTC set as Freeze Frame and Failure Records data.
Conditions for Clearing the MIL/DTC
^ The PCM/ECM will turn OFF the MIL during the third consecutive trip in which the diagnostic has been run and passed.
^ The History DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.
^ The DTC can be cleared by using the scan tool.
Diagnostic Aids
^ If the condition is not present, refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.
^ Review the Freeze/Failure Records vehicle mileage since the diagnostic test last failed. This may help determine how often the condition that caused the DTC to be set occurs.
Test Description
Steps 1 - 12:
Steps 13 - 21:
The numbers below refer to the step numbers on the diagnostic table.
2. Listen for an audible click when the cooling fan 1 relay operates. Command both the ON and OFF states. Repeat the commands as necessary.
3. Listen for an audible click when the cooling fan 2 and cooling fan 3 or S/P relays operate. Command both the ON and OFF states. Repeat the commands as necessary.
4. Tests for voltage at the coil side of the cooling fan 1 relay. The COOL FAN #1 fuse supplies battery positive voltage to the coil side of the cooling fan 1 relay.