P0661 code definition
The P0661 code means that the PCM or another control module on the car has detected voltage from the intake manifold tuning valve control circuit that is lower than the automaker’s settings.
What the P0661 code means
A P0661 code will be stored in the car’s computer when the PCM or another control module notes that the voltage reading from the intake manifold tuning valve control circuit is lower than what it should be. This is monitored during both key on/engine off and key on/engine running self-tests, although it may take up to eight drive cycles for the code to set.
What causes the P0661 code?
A range of different issues could cause the P0661 code to set, including the following:
- A bad driver in the PCM (likely)
- A faulty intake manifold tuning valve
- An open or short in the intake manifold tuning valve control circuit
- A loose connection within the circuit
- Faulty fuel injector control module
What are the symptoms of the P0661 code?
Symptoms for the P0661 code vary, and can include:
- Check Engine Light on
- Engine stalling
- Rough engine operation at idle
- Reduced fuel economy
- Reduced acceleration
How does a mechanic diagnose the P0661 code?
Diagnosing the P0661 code begins by reading the codes stored in the car’s computer using a handheld OBD II scanner. The mechanic will note those codes, and then clear them, and test drive the vehicle to see if they reset.
The mechanic will also need to visually inspect all the wiring and connectors in the intake manifold tuning valve control circuit for opens, shorts, corrosion or other damage. It should be noted that damage to the wiring harness or a loose/poor connection are some of the most common issues here.
The mechanic should use an advanced scanner to determine the general area of the problem, rather than testing each individually. In addition, it may be necessary to have a CAN scanner to rule out CAN bus failure.
The mechanic should also test the PCM, as failed drivers are one of the more common causes of the P0661 code. The intake manifold tuning valve will also need to be tested for operation. Once the underlying problem has been diagnosed and repaired, the vehicle must be test driven again for drivability and to determine proper operation.
Common mistakes when diagnosing the P0661 code
One common mistake here is attempting to repair the condition by addressing related symptom codes. For instance, a misfire code may be present, but that is not the actual problem, and attempting to fix it will not alleviate the condition that caused the code to set in the first place. In order to provide an accurate diagnosis, the mechanic should start with the earliest code and work forward to the most recent.
How serious is the P0661 code?
Your car may still be drivable even with the P0661 code stored. However, because this code can mean you will eventually experience drivability issues, it is important to have it fixed as soon as possible.
What repairs can fix the P0661 code?
The most common repairs for the P0661 code include the following:
- Reinstalling the driver in the PCM
- Replacing a failed intake manifold tuning valve
- Repairing loose or corroded connections in the wiring for the intake manifold tuning valve
Additional comments for consideration regarding the P0661 code
It can be time consuming to diagnose the P0661 code as there are many potential problems, and circuit/wiring testing alone can be exhaustive. However, it is vital to diagnose the underlying problem, rather than “throwing parts” at the problem.
Need help with a P0661 code?
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