Powertrain, generic (extended)

P2893 Cylinder 1 Ion Current Sense Circuit High

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

With P2893 the ion signal from cylinder 1 sits above its plausible ceiling. A signal line touching a supply voltage is the most direct explanation; crosstalk from the ignition primary circuit or a defective evaluation stage that saturates can show the same picture. Because knock is recognised from fast oscillations superimposed on the ion current, a signal pinned high leaves no room for that information, and the module will usually retard timing on cylinder 1 for safety. Saab's ion detection module, for instance, receives the cylinder 1 trigger on pin 9 and the matching ion input on pin 16, both of which can be checked for foreign voltage. A public manufacturer description of P2893 does not exist. Compare P2892 for the low reading and P2897 for cylinder 2.

Likely causes

Ion signal wire of cylinder 1 shorted to a voltage source
Internal fault in coil 1 coupling ignition voltage into the signal
Saturated input in the ion processing module

Symptoms

  • MIL with cylinder 1 ion fault
  • Reduced power and possibly higher fuel consumption
  • Knock may go unnoticed on cylinder 1

Repair estimate

DifficultyMediumDIY possible
Parts and labour€40–600
Time0.3–2 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

spark plug cyl 1ignition coil cyl 1ion sense module

Related codes

P2890P2891P2892P2897

References: law.cornell.edu, saabwisonline.com, en.wikipedia.org.