DTC P0720, P0721, P0791, P0794, P1900: Input Shaft Speed And Output Shaft Speed Sensors 5R44E And 5R55E Only

WARNING: This page is about a different variant/trim than selected.

Fig 1: DTC P0720, P0721, P0791, P0794, P1900 - Detection Conditions And Possible Causes

Courtesy of MAZDA MOTORS CORP.

DTC P0720, P0721, P0791, P0794, P1900 - INPUT SHAFT SPEED AND OUTPUT SHAFT SPEED SENSORS 5R44E AND 5R55E ONLY

DTC P0720, P0721, P0791, P0794, P1900		INPUT SHAFT SPEED (ISS) AND OUTPUT SHAFT SPEED (OSS) SENSORS 5R44E AND 5R55E ONLY
STEP	INSPECTION		ACTION
1	Was PCM Quick Test performed?	Yes	Go to step 2.
1	Was PCM Quick Test performed?	No	Perform PCM Quick Test. See PCM QUICK TEST .
2	DRIVE TEST Access ISS (P0791, P0794) or OSS (all others) PID with the WDS or equivalent tester. While monitoring ISS or OSS PID, drive the vehicle so that the transmission upshifts and downshifts through all gears. Does the ISS or OSS PID increase and decrease with engine and vehicle speed or is the sensor signal erratic (drop to zero or near zero and return to normal operation) ?	Yes	If the ISS or OSS PID increases and decrease with engine and vehicle speed, clear all DTCs. Road test to verify if concern is still present. If concern is still present, See SYMPTOM TROUBLESHOOTING CHART - AUTOMATIC TRANSMISSION . If the sensor signal is erratic, Inspect for intermittent concern in the internal/external harness, sensor, or connector and repair. Go to step 4.
2		No	If the ISS or OSS PID does not increase and decrease with engine and vehicle speed, inspect for open or short in vehicle harness, sensor, a PCM concern, or internal hardware concern. If the sensor signal is steady, go to step 3.
3	CHECK RESISTANCE OF ISS OR OSS SENSOR For ISS and OSS sensor: Disconnect the appropriate vehicle harness connector from the sensor. Connect ohmmeter negative lead to one pin of the sensor and the positive lead to the other pin on the sensor and record the resistance. Is the resistance within specification: 325-615 ohms for TSS sensor, and 305-375 ohms for OSS sensor?	Yes	See SYMPTOM TROUBLESHOOTING CHART - AUTOMATIC TRANSMISSION for concern diagnosis.
3		No	Replace sensor. See OSS SENSOR 5R44E/5R55E REMOVAL/INSTALLATION . See INTERMEDIATE SHAFT SPEED (ISS) SENSOR REMOVAL/INSTALLATION . Go to step 4.
4	VERIFY TROUBLESHOOTING OF DTCs COMPLETED Make sure to reconnect all disconnected connectors. Clear DTCs from PCM memory using WDS or equivalent tester generic OBD-II function. Perform PCM Quick Test. Is same DTC present?	Yes	Replace PCM and repeat PCM Quick Test.
4		No	If any other DTC is present, go to applicable DTC inspection. If no DTC is present, troubleshooting complete.