Tech Tip: Servicing Honda Knock Sensors

Tech Tip: Servicing Honda Knock Sensors

If the check engine light is on in a customer's 1998 Honda Accord EX, with trouble code P0325, it could be caused by the knock sensor, the connection, wire harness or the Engine Control Module (ECM). Replace the knock sensor and the trouble code resets.

If the check engine light is on in a customer’s 1998 Honda Accord EX, with trouble code P0325, it could be caused by the knock sensor, the connection, wire harness or the Engine Control Module (ECM). Replace the knock sensor and the trouble code resets.

Tests:
1. With the knock sensor unplugged and using a digital volt ohmmeter (DVOM), check for 0.02V to 0.03V reference voltage from the ECM to the knock sensor.

2. Next use a scope and look for an AC voltage signal from the knock sensor when the engine rpm is increased. It should have a very rapid AC voltage pattern of 1V positive and 1V negative. If the signal is OK, verify that signal is correct back to the ECM. If there is no harness or knock sensor problem, always verify the connection at the ECM before replacing the ECM.

Tech Tips:
The knock sensor harness is a shielded wire, so also unplug the alternator and verify that there is no interference in that circuit.

Courtesy of Identifix.

For more information, visit www.identifix.com.

You May Also Like

Toe Angles and Ride Height 

Zero toe angle is present when both tires are parallel to the center thrustline.

How can a mysterious case of tire wear occur in a perfectly aligned vehicle? It happens and the answers aren’t always simple. To better explain, let’s go back a few decades when I aligned a 1983 Mitsubishi RWD pickup, only to have it return a month later with a tire scuffing complaint. Although the outside edge of the right front tire showed evidence of toe-related wear, the current toe angle was 0.100 inches, which is within the Mitsubishi’s +0.080” to +0.350“ specification.

Sona Comstar Inaugurates Manufacturing Plant in Mexico

The new facility will specialize in producing differential assemblies and reduction gears meticulously designed for BEVs.

Axle Torque Procedures

Guessing the correct torque setting is a bad idea.

What Constitutes A Quality Wheel Hub Assembly?

Discover key factors to consider for quality hub assemblies and how they impact vehicle performance and longevity.

Needs Come First When Choosing Aftermarket Or OE

It’s essential to understand the differing needs of manufacturers, shops, technicians, and consumers.

Other Posts

Service Opportunities Still Exist With EVs

Like all ICE vehicles, you need the correct tools, parts and to follow the proper service procedures when servicing EVs. This video is sponsored by The Group Training Academy.

Do Technicians Need Tips?

Asking for a tip would not go over well with your future customers.

Wheel Bearing Shortcuts

When you’re installing a wheel speed sensor on a hub unit, never ever remove it from the original unit. Sponsored by Auto Value and Bumper to Bumper.

Green Li-ion Launches Lithium-Ion Battery Materials Plant

The plant is North America’s first commercial-scale plant to produce recycled lithium-ion engineered battery materials.