P289B code meaning
Cylinder 3 Ion Current Sense Circuit High
Powertrain system Generic code P28xx codes Check engine light
What P289B means
P289B signals that the ion channel of cylinder 3 sits permanently above its upper limit. A conductor touching battery voltage, a coil that couples ignition energy into its measuring output, or a lost ground reference are the usual electrical reasons. Saab shows a comparable bank-level check on the Trionic T7 V6, where cylinder 3 belongs to bank 1 together with 1 and 5: its code P1313 is set when the combustion detection line stays above 5 V for 200 combustions and clears after 300 without fault. On the 2009 four-cylinder module, cylinder 3 has trigger input pin 2 and ion input pin 8, which makes targeted voltage checks easy. No manufacturer publishes P289B. The low-side counterpart is P289A.
P289B 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 P289B
- MIL with high ion signal fault on cylinder 3
- Knock on cylinder 3 may go undetected, so timing is retarded
- Reduced pulling power
Common causes of P289B
- Most likelyIon signal wire of cylinder 3 shorted to battery or supply voltage
- PossibleCoil 3 coupling ignition energy into its measuring output
- Less likelyMissing ground reference at coil 3 or the processing module
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Spark plug cyl 3Ignition coil cyl 3Ion sense module
What each part of P289B 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. |
| 9B | The exact fault in that area. |
What to do next
- Note P289B 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 P289B
What does P289B mean?
P289B means "Cylinder 3 Ion Current Sense Circuit High". P289B signals that the ion channel of cylinder 3 sits permanently above its upper limit. It is a generic code, so it means the same on every make.
Is it safe to drive with P289B?
Drive gently and only to a workshop. With P289B the car can go into limp mode (reduced power) to protect itself.
Will P289B fail an emissions test?
Yes, it can. P289B 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 P289B 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 P289B clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.