06 Honda Odyssey Battery Warning Light Stays On While Engine is Running: Diagnosis and Repair

by parker
YouTube video


In this article, we will be discussing the common issue of the battery warning light staying on in a 2006 Honda Odyssey. Many Honda Odyssey owners have reported this issue, where the battery light remains illuminated even when the engine is running. This can cause frustration for the owners, as it often results in the battery dying and the need for frequent jump starts. In this article, we will discuss the possible causes of this issue, how to diagnose the problem, and the steps to repair it.

Possible Causes

There are a few potential causes for the battery light staying on in a Honda Odyssey. The most common cause is a defective alternator. If the alternator is not charging the battery properly, it can cause the battery light to remain on. Additionally, there may be a problem with the wiring between the battery and the alternator, such as high resistance in the power supply wire or a problem with the control wire between the computer and the alternator. Finally, a defective battery with a bad cell could also cause the battery light to remain on.

Diagnostic Steps

To diagnose the issue, the first step is to check the battery voltage. Using a multimeter, connect the red lead to the positive terminal of the battery and check the voltage with the engine off. A good battery should have a voltage of around 12.6 volts. If the battery voltage is within range, start the engine and check the voltage again. With the engine running, the voltage should increase to around 13.5-14 volts. If the voltage remains low, it indicates a problem with the charging system.

Next, inspect the serpentine belt to ensure it is in good condition and properly installed. A damaged or loose belt could cause the alternator to not function properly. If the belt appears to be in good condition, further testing is required.

Diagnostic Testing

To further diagnose the issue, access the alternator and its electrical connector. Consult the wiring diagram to understand how the charging system works. There are five wires that connect to the alternator, two of which provide power from the fuse boxes, and three that come from the computer.

Using a scope or a multimeter, back probe the wires and check for voltage on each one. The black wire and the black wire with a yellow trace should have 12 volts with the key on or the engine running. The other three wires are control wires from the computer and should exhibit specific signals.

Repair Steps

If all the signals are present, it indicates that the problem lies with the alternator itself. It is advisable to replace the alternator with a new or refurbished unit to restore the charging system. Before replacing the alternator, ensure that the power supply to the alternator and the ground connections are secure and free of any voltage drops.

However, if any of the signals are missing or abnormal, further troubleshooting is required. Check the wiring for any loose connections or damage and repair as necessary. If the wiring is in good condition, the issue may be with the computer or a control module.


In conclusion, the battery warning light staying on in a 2006 Honda Odyssey can be caused by various factors. Most commonly, a defective alternator or a problem with the wiring between the battery and the alternator is to blame. Through careful diagnosis and testing, the root cause of the issue can be identified and repaired. By following the steps outlined in this article, Honda Odyssey owners can resolve this frustrating problem and ensure their vehicle’s charging system functions properly.

Related Videos

Adblock Detected

Please support us by disabling your AdBlocker extension from your browsers for our website.