P0075 Intake Valve Control Solenoid Circuit (Bank 1)

Technical Description of OBD-II Trouble Code

Circuit for Controlling the Intake Valve Solenoid (Bank 1)

What does that signify?

This code is a generic OBD-II powertrain code, which means it is applicable to all vehicle makes and models (1996-newer). However, the specific repair steps may vary depending on the model.

In vehicles equipped with variable valve timing (VVT), the Engine Control Module / Powertrain Control Module (ECM/PCM) regulates the camshaft position by controlling the engine oil flow through the control solenoid to adjust the camshaft position. The control solenoid is operated using a Pulse Width Modulated signal (PWM) from the ECM/PCM. The ECM/PCM monitors this signal, and if the voltage is outside the specified range or intermittent, it will trigger this DTC and activate the Check Engine Light / Malfunction Indicator Lamp (CEL/MIL).

Bank 1 refers to the side of the engine with cylinder #1 – make sure to verify according to the manufacturer’s specifications. The intake valve control solenoid is typically located on the intake manifold side of the cylinder head. This code is similar to codes P0076 and P0077. It may also be accompanied by P0026.

Symptoms

The symptoms may include:

Potential Causes

The potential causes of a P0075 diagnostic trouble code may include:

Diagnostic Steps

Wire harness – Check for unplugged harness connections, look for corrosion or loose wires to connectors. Unplug harness connectors from solenoid and PCM, and using a wiring diagram, locate the + and – wires to the solenoid. The solenoid can be ground side or power side controlled, depending on the application. Check with factory wiring diagrams to determine the power flow in the circuit. Using a digital volt ohm meter (DVOM) set to the ohms setting, check for resistance between each end of the wire. An over limit reading on the DVOM may indicate an open in the wiring, loose connection, or terminal. The resistance should be around 1 ohm or less. If there is excessive resistance, there may be corrosion or faulty wiring between the solenoid and PCM/ECM.

Control solenoid – With the electrical harness to the solenoid unplugged, use the DVOM set to ohms to check for resistance between each of the electrical terminals on the control solenoid itself. Use the factory specifications or a known good control solenoid, if available, to determine if there is excessive resistance in the solenoid. If there is an over limit or excessive resistance reading on the DVOM, the solenoid is likely faulty. Check for a short to ground through the control solenoid by connecting either DVOM lead to a known good ground and the other to each terminal on the control solenoid. If there is resistance present, the solenoid may be internally shorted.

Short to power – Unplug the harness to the PCM/ECM and locate the wires to the control solenoid. With the DVOM set to the volts scale, connect the negative lead to ground and the positive lead to the wire(s) to the control solenoid. Check for voltage. If there is voltage present, there may be a short to power in the wiring harness. Locate the short to power by unplugging harness connectors and testing the wiring back to the solenoid.

Short to ground – Unplug the harness to the PCM/ECM and locate the wires to the control solenoid. With the DVOM set to the volts scale, connect the positive lead to a known good voltage source such as the battery and the negative lead to the wire(s) to the control solenoid. Check for voltage. If there is voltage present, there may be a short to ground in the wiring harness. Locate the short to ground by unplugging harness connectors and testing the wiring back to the solenoid. Check for a short to ground through the control solenoid by connecting either DVOM lead to a known good ground and the other to each terminal on the control solenoid. If there is a low resistance present, the solenoid may be internally shorted.

PCM / ECM – If all wiring and the control solenoid checks out okay, it will be necessary to monitor the solenoid during engine operation by back probing the wires at the PCM/ECM. Use an advanced scan tool that can read the engine functions to monitor the duty cycle commanded to the control solenoid. It will be necessary to monitor the solenoid during engine operation under various engine RPMs and load. Use an oscilloscope or graphing multimeter set to the duty cycle scale, connect the negative lead to a known good ground and the positive lead to either wire terminal at the solenoid itself. The reading on the multimeter tool should match the commanded duty cycle on the scan tool. If they are opposite, the polarity may be reversed – connect the positive lead on the other wire terminal to the solenoid and re-test to verify. If no signal is detected from the PCM, there may be a fault with the PCM itself.

Professional Service

While we always recommend resolving this issue through mechanical means, if that is not possible, we offer the option to permanently delete this specific DTC. We will continue to work on all other codes. If you are interested in this option, please upload your ECU file to our portal.