98 99 CUMMINS ISB ECM ECU DIESEL ENGINE COMPUTER PART# P3942860. PLEASE ENSURE FITTING BEFORE PURCHASING. PLEASE RESEARCH/ENSURE FITMENT OF PART TO YOUR SPECIFIC VEHICLE BEFORE PURCHASING. IF YOU HAVE ANY QUESTIONS ABOUT FITMENT PLEASE FEEL FREE TO MESSSAGE US BEFORE PURCHASING AND WE WILL GET BACK TO YOU AS SOON AS POSSIBLE. Please research/ensure fitment of part to your specific vehicle before purchasing.