P0704 - CLUTCH SWITCH INPUT CIRCUIT MALFUNCTION

The Clutch Pedal Position (CPP) is a normally closed switch. The Transmission Control Module (TCM) or Powertrain Control Module (PCM) detects an ignition voltage in the CPP circuit.

When the clutch pedal is depressed or the clutch switch is open, the control module detects 0 volts in the circuit. When the clutch switch closes, the clutch is released and the control module senses a preset voltage signal and then sends information in series to the Engine Control Module (ECM).

The DTC code P0704 OBD2 is stored when the signal from the CPP switch is not received by the control module. This code determines if the CPP switch has failed to seek a clutch switch transition during a predetermined drive cycle.

• The fault indicator light (Check Engine) is illuminated.
• A failed engine start.
• It lowers fuel efficiency.
• Excessive engine RPM at idle.

The reasons for setting the diagnostic code P0704 OBDII are

• Clutch switch wiring or connectors may be defective causing shorts in the circuit.
• The clutch pedal lever may be worn out.
• The clutch switch may be defective.
• The fuse has blown or the link to fuse is in bad condition

To solve the fault code P0704 OBD2, you must this:

• Perform a clutch switch wire inspection. Check all system fuses for proper operation. If necessary, replace the bad fuses. Also, inspect the battery cables as well as the alternator output.
• Use a DVOM to check the battery voltage in the clutch switch input circuit. Consult all data to determine how the clutch switch is distributed since some vehicles are equipped with multiple switches. If the input circuit has electrical energy, press the clutch pedal and check the battery voltage in the output circuit. If there is no energy in the output circuit, the clutch switch may be misadjusted or defective.
• If voltage is present on both sides of the switch, check the clutch switch input circuit on the PCM. Compare the readings obtained with the manufacturer's specifications.
• If there is no input signal from the switch on the PCM connector, disconnect all related controllers and perform resistance tests on all system circuits with the If there are any open or shorted circuits, repair them.
• Test the system fuses by keeping the clutch pedal depressed.