P0489 Code: Exhaust Gas Recirculation Control Circuit Low
The P0489 code indicates low voltage in the control circuit of the EGR valve, from a short to ground or a lack of power. Expect an unstable idle, stalling when you stop and pinging under load. Carbon is the number one mechanical problem.
- Severity
- Medium
- Can I keep driving?
- Yes, but with caution
- Estimated cost
- $80 to $600
- Difficulty
- Medium
- System
- Emissions Control
- Applies to
- All OBD2 vehicles
On this page
What the P0489 code means
The computer controls how far the EGR valve opens with a vacuum solenoid or an electric motor. That is how it regulates how much exhaust gas goes back into the intake, depending on load and temperature.
The computer monitors the control circuit from its own driver transistor. The P0489 code indicates low voltage in the control circuit (a short to ground or a lack of power). Before replacing the component, check the fuse, relay, connector and wiring, since they are the most common cause.
If the valve does not obey, two things can happen: it can stick closed (pinging under load, high NOx) or stick open (unstable idle, hesitation, the engine stalls when you stop). Carbon on the valve seat is the most frequent mechanical cause.
To confirm it, unplug the component with the key on and watch what happens to the reading or the code. If the value jumps to the opposite extreme, the wiring is fine and the component is the one pulling the signal to ground. If it does not change, look for the short in the wire, starting where the harness rubs against the engine, the chassis or the exhaust.
P0489 code symptoms
- Check engine light on.
- Unstable idle, or the engine stalls when you stop.
- Pinging when accelerating under load.
- Loss of power (diesel).
Likely causes of the P0489 code
- Control wire shorted to ground. The component may stay energized all the time, or the computer cuts the command to protect itself.
- Interrupted power supply, from a fuse or relay.
- Shorted component, with a resistance far lower than specified.
How to diagnose the P0489 code step by step
- Command the component with the scan tool and check whether it responds.
- Check the fuse and relay.
- Measure the supply at the connector: battery voltage with the key on or when it is commanded.
- Measure the component resistance and compare it with the manual. Also check the insulation to ground.
- Check the control wire for continuity and for shorts.
- Command the EGR with the scan tool. At idle the engine should stumble if the valve opens and the passages are clean.
- Remove and clean the valve and check the EGR passages.
How to fix the P0489 code
- Repair the connector, the wiring or the power supply.
- Replace the EGR valve if it does not respond with correct power and control.
- Clear the codes and verify that the monitor completes.
Technical reference data
- Solenoid or control motor: 12 V with PWM control.
- Approximate solenoid resistance: 10 to 30 ohms.
- Approximate values only: check the manufacturer data for your engine.
Brand-specific notes
Carbon is the number one problem on diesels and on many GDI engines.
P0489 on Volkswagen TDI
Carbon buildup is the leading problem on Volkswagen TDI engines.
P0489 on Ford TDCi
Carbon buildup is the leading problem on Ford TDCi engines.
P0489 on Toyota D-4D
Carbon buildup is the leading problem on Toyota D-4D engines.
Questions about the P0489 code
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