GEAR-SUN (16 teeth) 2V5721 - Caterpillar

MID 036 CID 1087 FMI 08Conditions Which Generate This Code:The oxygen buffer has been powered for at least 60 seconds. The frequency (PWM) for the oxygen signal is more than 625 Hz OR the duty cycle is not within the valid range of 10 to 90 percent. The 1088 - 06 Oxygen Sensor Power Supply open circuit diagnostic code is not active.System Response:Compensation for fuel quality is disabled. The diagnostic code will remain active until the following conditions occur:
The frequency for the oxygen signal is less than 625 Hz.
A duty cycle between 10 and 90 percent is present for at least five seconds.The alarm output is activated. The code is logged.Possible Performance Effect:Engine performance and emissions may be affected.Troubleshooting:Test Step 1. Perform the following diagnostic procedure: "Oxygen Sensor Signal"Results:
OK - STOP