P0650 Code: What It Is And How To Fix It

Warning lights are designed to alert the driver of current faults, potential safety hazards, and disabled systems. One of the most dreaded warning lights is the Check Engine Light (CEL). Other names commonly used other than CEL are the Malfunction Indicator Lamp (MIL) and Service Engine Soon (SES) lights. Like other warning lights, the Powertrain Control Module (PCM) controls when the MIL turns on. If the MIL does not operate or the light remains stuck on the PCM, it will indicate it no longer has control and the P0650 Malfunction Indicator Lamp (MIL) Control Circuit error code will be set. If your vehicle’s PCM is setting the P0650 error code, fear not, as we have you covered in this article. Our guide includes the causes of the P0650 code, how to repair it, and how much you can expect to pay to have it fixed.

What Does The P0650 Error Code Mean?

Diagnostic Trouble Codes (DTCs) are set and stored by the PCM at the time a fault is detected. In the case of the P0650 error code, the PCM has identified that it no longer has control of the MIL. This can result in the MIL being stuck ‘on’ or stuck ‘off’. The PCM performs a self-test when the ignition is set on. If the PCM finds that the MIL fails the self-test, the P0650 code will be stored in the PCM. This fault code can come as a shocker because in some scenarios the MIL is not illuminated, and the driver is completely unaware the fault has been stored. In most cases, the vehicle owner/driver does not become aware of the fault unless the vehicle has failed an emissions test. The MIL is turned on and off by the PCM that controls the circuit via a transistor.

What Causes The P0650 Code?

The P0650 error code is most commonly caused by circuitry issues. The following are the reported faults that trigger this code:

• Faulty circuit wiring
• Loose or corroded wiring connections
• Failed instrument cluster
• Faulty PCM

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What Are the Symptoms Of The P0650 Error Code?

The following are the reported symptoms associated with the P0650 error code:

• Illuminated check engine light
• Inoperable check engine light
• Failed emissions test

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Can I Still Drive With The P0650 Error Code Present?

The MIL is designed to alert the driver of a malfunctioning engine. Other than an illuminated MIL and the symptoms a vehicle exhibits, it can be hard to know exactly how severe the fault code is without a system scan. The P0650 error code is one that you could likely continue driving with. However, the main issue presented with driving with the P0650 code active is the inability to identify the presence of other more serious DTCs. If the MIL is not able to illuminate or constantly remains illuminated, there can be no way to tell other than to have the On-Board Diagnostics (OBD-II) system scanned regularly. Having your car’s system scanned frequently can be inconvenient and unrealistic, even if you possess a scanning tool. Due to the inability to identify fault codes with the P0650 code present, we recommend you seek repairs when possible.

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How To Fix The P0650 Error Code

Repairing the P0650 code will begin with an OBD-II system scan. The purpose of the scan is to verify the fault code is active, indicating the fault is present and currently affecting the vehicle. If a code is stored as ‘history’, it means the fault is no longer active/present. If the code is stored as ‘pending’, it means it has not yet been logged as an active or current fault, but it could be if the enabling fault conditions are met again. OBD-II scans can be performed by repair shops, emissions testing centers, and parts stores. The scans are usually complimentary if performed by a parts store. To properly diagnose the P0650 code, you’ll need to be fairly handy with wiring diagrams and using a multimeter. For the average person, this diagnosis can be fairly involved and is best left to the professionals. We’ll cover some of the steps along with the typical culprits that cause the issue.

Wiring Inspection And Fuse Replacement

To inspect the wiring of the MIL circuit, you’ll have to remove the instrument cluster first. Sometimes, the wires that connect to the instrument cluster become frayed or damaged and/or the connector can become loose, resulting in the P0650 error code.

You can inspect a fuse using a test light or multimeter. A blown fuse can often be the reason for the P0650. Before removing an instrument cluster, we recommend you check all the fuses on the MIL circuit.

Removing the instrument cluster can typically be done with basic hand tools, a soldering iron, and a little patience. Below are some of the steps involved in removing an instrument cluster:

1. Remove the surrounding trim. This may require removing screws and/or plastic retaining clips.
2. Remove the instrument cluster retaining screws. There are usually four of these.
3. Tilt the instrument cluster to gain access to the electrical connectors to disconnect them.
4. Once the wiring harness is disconnected, the cluster can be removed.

Inspect the cluster wiring harness carefully. If you suspect a loose wire or connector is at fault, plug the cluster in and shake/wiggle the wiring. If the check engine light flickers, the fault is likely to be a loose connection. If torn or broken wires are found, you’ll need to repair them correctly using a soldering iron.

Checking For A Faulty Instrument Cluster

A faulty instrument cluster is often found to be the culprit of the P0650 error code. To rule out a faulty instrument cluster, you’ll need a bidirectional scan tool, a wiring diagram, and electrical circuit knowledge. The P0650 error code can be set by a blown bulb. This is a repair we’d recommend leaving to the pros. However, sometimes a faulty instrument cluster can occasionally be repaired with a little solder. Soldered connections can ‘break’ or crack and one way to repair them is to carefully apply new solder. This method is often used to repair the P0650 code on Chevy models like the Silverado, and on several other vehicles.

To perform this repair, follow these steps:

1. Carefully remove and disassemble the instrument cluster.
2. Inspect the cluster circuit board and bulbs. Look over every solder joint carefully. A blown bulb and cracked or loose solder joints can be difficult to identify. When found, replace the bulb or use a soldering iron and ‘rosin core’ solder; apply solder to repair improper joints and connections.

Unfortunately, not all instrument clusters can be repaired by this method. One option is to send the instrument cluster out for repair.

Powertrain Control Module

Before considering a PCM replacement, you’d want to be certain that this will remedy the issue, in light of the costs associated with this component. PCMs are not cheap and there isn’t always an aftermarket option available for all vehicle makes and models. This leaves you having to rely on the OEM and dealerships, which means it can be costly. We recommend letting the pros diagnose your vehicle if you suspect a faulty PCM is the issue.

How Much Does It Cost To Fix The P0650 Error Code?

Repairing the P0650 can cost as little as $20 and as much as $1,500 depending on the exact fault of the vehicle. Simple wiring repairs, a fuse replacement, or soldering repairs can be performed for as little as $20, if you do them yourself. If a repair shop handles these, you should expect to pay $100 to $250. RepairPal estimates an instrument cluster replacement will cost around $930. Sending your instrument cluster out for repair to a specialist will typically cost about $200. Purchasing a refurbished instrument cluster, meanwhile, can cost between $200 and $500. When it comes to PCM replacements, RepairPal estimates the repair will cost approximately $1,100. However, we’ve seen replacement modules cost as much as $1,500, depending on the make/model. Like instrument clusters, PCMs can be sent out for repair. This service usually costs $200 to $500.

The P0650 code is not as common as other DTCs, but it does, unfortunately, make an appearance on some vehicles. You can delay repairing the P0650 error code as long as you are cautious as the vehicle may not illuminate the check engine light. Repair costs vary widely depending on the fault, make, and model of vehicle that is affected. In some scenarios, vehicle owners may be able to handle the repairs themselves. In others, it may be best to let a professional auto repair shop handle it.

What is the MIL circuit malfunction?

As described above, this fault refers to an issue with the vehicle’s Malfunction Indicator Lamp. If this light isn’t operating correctly, drivers may not be alerted of serious vehicle issues.

I want to know how to fix the Malfunction Indicator Lamp control circuit?

Fixes for this problem can range from simple and cheap wire repairs to a complete PCM replacement. We recommend consulting the pros before considering a PCM replacement.

What is the Malfunction Indicator Lamp on a Tahoe?

As on any other vehicle, the MIL on a Chevrolet Tahoe is also known as the check engine light. It can alert the driver to a wide array of minor or serious faults with the vehicle.