P0689 OBD Error Code: Problem & Solutions

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The trouble code P0689 can be elucidated as ECM/PCM Power Relay Sense Circuit Intermittent. If there is storage of P0689 fault code, then it would mean that the powertrain control module has detected some abnormality in the relay which supplies it with voltage. This specific error code would be stored when the power relay sensor circuit voltage would exceed the maximum allowable parameter. This diagnostic fault code is a generic powertrain code, which means that it would apply to the OBD-II equipped vehicles. The specific repair steps can vary as it depends upon the vehicle make and model.

This trouble code is generic, which would mean that it can apply to all the vehicles which are equipped with the OBD-II or the vehicles which are made since 1996 up to the present. The specifications on the definition, the troubleshooting steps as well as repairs can always vary from one vehicle to another. The voltage to the ECM/PCM power relay is being monitored by the engine control module. This trouble code would be set by the ECM when the ECM/PCM power relay would not be as per the specifications set by the manufacturer.

What causes this problem with the ECM/PCM Power Relay Sense Circuit Intermittent?

• There might be weak battery
• Less voltage while cranking
• Defaults in the engine control module (ECM) relay
• There can be blown ECM fuse
• Malfunctioning ECM
• ECM harness might be unlocked
• ECM circuit might have bad electrical connection

1. Engine Control Module - Dead cells in batteries can cause a failure in the engine control module. Many times a battery is left in the rig long after a cell has died. This would affect the grounding in the car battery.
2. Oil Pressure Gauge - The main function of the oil pressure gauge is to make sure that the lubricants reach the areas they need to, including the camshaft, main, and balance shaft bearings. Buy top notch oil pressure gauge from us at economical prices.
3. Car Battery - Faulty car battery can have the problem of overheating and fast discharging. Thus, it can affect the motor performance as well as damaged major components. Replace it immediately.
4. Powertrain Control Module - If there are some faults in the PCM, then it may throw off the timing and fuel settings of the engine, which can negatively affect the performance. A flawed PCM may cause the vehicle to experience a reduction in fuel efficiency, power as well as acceleration.
5. Power Relay - Damaged power relay will affect the pump circuit and thus hamper the performance of the transmission fluid pump going from delays response to not working at all. Thus, replace it now!
6. Ignition Coil - The failure in the ignition coil would also result in the stalling of the vehicle. This might occur due to irregular sparks sent to the spark plugs by the defective coil. So it is very important to replace the ignition coil with us at equitable prices.
7. Electronic Control Unit - Do you know that the poor performance or unexplained drops in fuel economy or efficiency are often associated to onboard car computer problems, or defective ECU issues?
8. Diagnostic Tools - Use factory grade diagnostic tools to resolve OBD code P0689 error. Buy new diagnostic tools and equipment for us.

You might be thinking that how would you diagnose these problems? We at Parts Avatar Canada would help you diagnose the major symptoms easily.

Common Symptoms

• Visibility in the check engine light
• Car engine might not begin
• There might be hard or no start in cold weather
• Electrical accessories might not operate properly

Looking out for some ways with the help of which you can correct this fault code? Then you have arrived at the correct place. We are here to help you out, so you must check out the steps mentioned below as follows:

• Rehabilitate the defaults in the ECM/PCM power relay sense circuit
• The malfunctioning battery cables should be repaired or replaced as per the need
• Make sure to mend the faulty PCM wiring, connectors
• It is essential to restore the flawed fuse or fusible links
• Carefully adjust the faults in the PCM/ECM
• Recondition the non-functioning car battery

There is no need to get strained if your OBD Code is still flashing up as we are here at your service. Have a look at our superior variety of car battery, ecm fuse, engine control module relay, ecm power relay harness, pcm module, ecm module and many more. Now all your problems would vanish within no time.

Here are some steps which you should follow in order to diagnose this fault code:

• This is a general type of error code which is diagnosed with the help of a scanner.
• The mechanic will insert a scanner to diagnostic port of the vehicle and recover the codes and freeze frame data.
• If he happens to find any additional error codes, he has to address them as well.
• Once it is done, he has to reset the vehicle, and then test drive to see if the error code appears.
• If the error code does not return, then there can be an erratic condition.
• Then the mechanic has to check the wires, connectors and other electrical components and quickly replace them if he finds them to be damaged or defective.
• Most of the latest vehicles utilize a PCM/ECM relay in order to supply the PCM with power and ground signals.
• The code should be cleared up and check the system to see if it returns, making sure to test drive the automobile.
• Now if the code is returning back again and the automobile is not starting, then unplug the PCM relay connector and check for reference voltage and ground signals, comparing them to the specifications set by the manufacturer.
• The car mechanic should make sure to unplug the PCM and all other associated modules before probing the circuits to avoid damage and control module memory loss.
• Check the powertrain control module to make sure it is not defective.

Common Mistakes When Diagnosing The P0689 Code

There are a lot of mechanics which make a common mistake of replacing the PCM when in reality it is the relay which is faulty. Due to these unnecessary repair/replacements, it would result in the recurrence of this error code.

P0688 - ECM/PCM Power Relay Sense Circuit Open

P0690 - ECM/PCM Power Relay Sense Circuit High