Tech notes On some Hyundai models, the P1623 code is for the “Check Engine Lamp”. If this codes is stored in the Engine Control Module (ECM), the check engine light is probably not illuminating. If this is the case the
Symptoms – Engine Light ON (or Service Engine Soon Warning Light) P1623 Information for specific makes P1623 BUICKP1623 CADILLACP1623 CHEVROLETP1623 GMCP1623 HYUNDAI
P1623 CHEVROLET – Transmission Temp Pull-Up Resistor
P1623 GMC – Transmission Temp Pull-Up Resistor
P1623 BUICK – Transmission Temp Pull-Up Resistor
P1623 CADILLAC – Transmission Temp Pull-Up Resistor