OBD codes / P0325 / Toyota Tacoma
P0325 on a Toyota Tacoma
Knock Sensor 1 Circuit Malfunction (Bank 1)
3.4L 5VZ-FE V6 (1995-2004) and 4.0L 1GR-FE V6 (2005-2015).
What P0325 usually means on a Tacoma
P0325 is the Tacoma's signature V6 code — a knock sensor circuit fault that turns up again and again on the 3.4L 5VZ-FE and 4.0L 1GR-FE. The knock sensors sit in the engine valley beneath the intake, and their sub-harness wiring corrodes or the sensors themselves fail with age and heat. When the ECU loses the knock signal it retards timing as a precaution, so you may notice slightly softer throttle response and a small dip in fuel economy along with the light. It's rarely a running emergency, but it's a very common Tacoma repair.
Most likely causes on this model
- Failed knock sensor
The 5VZ-FE and 1GR-FE knock sensors are a known wear item; one or both fail with age and set P0325.
- Corroded knock-sensor sub-harness
The connector and short harness under the intake corrode on high-mileage Tacomas, breaking the circuit even with good sensors.
- Wiring or connector damage
Heat and vibration in the valley chafe the wiring over the years.
- Rodent or repair-related harness damage
Because the sensors live under the intake, prior work or critters can disturb the wiring.
What it costs on a Tacoma
The knock sensors themselves are inexpensive, but on the Tacoma V6 they sit under the intake manifold, so most of the bill is labor to remove the intake and reach them. Because access is the hard part, it's smart to replace both sensors, the gaskets, and the sub-harness at the same time rather than going back in later. Expect a mid-range repair driven almost entirely by that access time.
Fixing it
Since the intake has to come off either way, do both knock sensors, a new sub-harness, and fresh intake gaskets in one visit — chasing them one at a time on a Tacoma V6 wastes the expensive labor.
For the full step-by-step diagnosis order (any vehicle), see the main P0325 guide.
Tacoma owners also ask
Is it safe to drive my Tacoma with P0325?
Generally yes for a while — the ECU pulls timing to protect the engine, so you lose a little power and economy rather than risk damage. But get it fixed before long, since you're running without real knock protection.
Why is a cheap sensor such an expensive job?
On the Tacoma V6 the knock sensors are buried in the engine valley under the intake manifold. The parts are minor; the cost is the labor to pull the intake to reach them.
Year, engine and mileage change the answer. Get a diagnosis for your Tacoma — it weighs these causes against your exact configuration and real complaint data.
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Based on widely reported patterns for this model; individual causes vary by year, engine and history. Generic P0325 behavior is covered on the main P0325 page. Confirm with a scan tool before buying parts.