P289F code meaning
Cylinder 4 Ion Current Sense Circuit High
Powertrain system Generic code P28xx codes Check engine light
What P289F means
P289F is set when the ion measurement of cylinder 4 is held above its plausible maximum. Electrically, look for a signal conductor in contact with a supply feed, an internally leaking coil 4, or a poor ground that lifts the reference level. On Saab's T7 V6, cylinder 4 is part of bank 2 with cylinders 2 and 6; there a combustion detection line above 5 V for 200 combustions sets Saab code P1324, which needs 300 fault-free combustions to report OK. On the 2009 four-cylinder module, the ignition trigger of cylinder 4 enters on pin 1, the ion signal on pin 15. A permanently high channel hides the knock oscillations, so timing is retarded. No manufacturer publishes P289F; P289E is the low case.
P289F at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyMedium, DIY possible
- Typical labor0.3 to 2 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P289F
- MIL with high ion signal on cylinder 4
- Reduced performance from retarded ignition
- Knock protection on cylinder 4 weakened
Common causes of P289F
- Most likelyIon signal conductor of cylinder 4 touching a supply feed
- PossibleInternal leakage in coil 4 raising the measuring output
- Less likelyPoor ground lifting the reference of the cylinder 4 channel
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Spark plug cyl 4Ignition coil cyl 4Ion sense module
What each part of P289F means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| 8 | Area: transmission. |
| 9F | The exact fault in that area. |
What to do next
- Note P289F and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P289F
What does P289F mean?
P289F means "Cylinder 4 Ion Current Sense Circuit High". P289F is set when the ion measurement of cylinder 4 is held above its plausible maximum. It is a generic code, so it means the same on every make.
Is it safe to drive with P289F?
Drive gently and only to a workshop. With P289F the car can go into limp mode (reduced power) to protect itself.
Will P289F fail an emissions test?
Yes, it can. P289F is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P289F to fix?
Difficulty: medium. A typical repair takes 0.3 to 2 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will P289F clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.