diff --git a/firmware/controllers/math/engine_math.cpp b/firmware/controllers/math/engine_math.cpp
index b5f40a444e..cbd7cbf432 100644
--- a/firmware/controllers/math/engine_math.cpp
+++ b/firmware/controllers/math/engine_math.cpp
@@ -113,7 +113,8 @@ static void registerSparkEvent(engine_configuration_s const *engineConfiguration
 		return; // error already reported
 
 	if (!isPinAssigned(pin)) {
-		warning(OBD_PCM_Processor_Fault, "pin not assigned for coil #%d", (int) pin - (int) SPARKOUT_1_OUTPUT);
+		// todo: extact method for this index math
+		warning(OBD_PCM_Processor_Fault, "pin not assigned for coil #%d", (int) pin - (int) SPARKOUT_1_OUTPUT + 1);
 	}
 	event->io_pin = pin;
 
@@ -173,7 +174,8 @@ static void registerInjectionEvent(engine_configuration_s const *e, trigger_shap
 		io_pin_e pin, float angle) {
 
 	if (!isPinAssigned(pin)) {
-		warning(OBD_PCM_Processor_Fault, "pin not assigned for injector #%d", (int) pin - (int) INJECTOR_1_OUTPUT);
+		// todo: extact method for this index math
+		warning(OBD_PCM_Processor_Fault, "pin not assigned for injector #%d", (int) pin - (int) INJECTOR_1_OUTPUT + 1);
 	}
 
 	registerActuatorEventExt(e, s, list->getNextActuatorEvent(), injectonSignals.add(pin), angle);