P0804

DTC P0804

Test 1-13:

Test 14-15:

Circuit Description
With the ignition ON battery voltage is supplied to the skip shift lamp through the Instrument Panel Cluster (IPC). The Powertrain Control Module (PCM) turns on the skip shift lamp at the same time the skip shift solenoid is enabled. The PCM controls the skip shift lamp by grounding the control circuit via an internal switch called a driver. The driver supplies the ground for the component being controlled. Each driver has a fault line which the PCM monitors. When the PCM commands a component to turn ON, the voltage of the control circuit should be low, near 0 volts. When the PCM commands the control circuit of a component OFF, the voltage potential of the circuit should be high, near battery voltage. If the internal fault detection circuit senses a voltage other than what is expected, the fault line status changes, causing DTC P0804 to set. DTC P0804 is a type C DTC.

Conditions for Enabling the Skip Shift Solenoid and Lamp
^ The Vehicle Speed Sensor (VSS) is between 24 - 31 km/h (15 - 19 mph).
^ The Engine Coolant Temperature (ECT) is 77°C (171°F) or greater.
^ The Barometric Pressure (BARO) is greater than 76 kPa.
^ The Accelerator Pedal Position (APP) is less than 21 percent.
^ Once the 1-4 Upshift solenoid is enabled the solenoid will not be re-enabled until the vehicle speed returns to 1 km/h (1 mph) and the conditions for enabling the 1-4 Upshift solenoid are met.

Conditions for Running the DTC
The engine is running.

Conditions for Setting the DTC
^ The PCM detects that the commanded state of the driver and the actual state of the control circuit do not match.
^ Condition must exist for a minimum of 5 seconds.

Action Taken When the DTC Sets
^ The PCM stores the DTC information into memory when the diagnostic runs and fails.
^ The PCM does not illuminate the Malfunction Indicator Lamp (MIL).
^ The PCM records the operating conditions when the Conditions for Setting the DTC are met. The PCM stores this information as Failure Records.
^ The PCM stores DTC P0804 in PCM history.

Conditions for Clearing the MIL/DTC
^ A scan tool can clear the DTC.
^ The PCM clears the DTC from PCM history if the vehicle completes 40 warm-up cycles without a non-emission-related diagnostic fault occurring.
^ The PCM cancels the DTC default actions when the fault no longer exists and the DTC passes.

Diagnostic Aids
^ Remove any debris from the PCM connector surfaces before servicing the PCM. Inspect the PCM connector gaskets when diagnosing/replacing the PCM. Ensure that the gaskets are installed correctly. The gaskets prevent contaminate intrusion into the PCM.
^ For any test that requires probing the PCM or a component harness connector, use the J35616 connector test adapter kit. Using this kit prevents damage to the harness/component terminals. Refer to Using Connector Test Adapters in Wiring Systems.
^ Low system voltage can cause this DTC to set. When reviewing captured data, verify if a low system voltage condition was present at the time the DTC was stored in memory.
^ For an intermittent condition, refer to Testing for Intermittent Conditions and Poor Connections.

Test Description
The numbers below refer to the step numbers on the diagnostic table.
2. Watch for the skip shift lamp to illuminate. Command both the ON and OFF states. Repeat the commands as necessary.
5. Verifies that the PCM is providing ground to the skip shift lamp.
6. Tests if ground is constantly being applied to the skip shift lamp.