DTC P0791 [FS5A-EL]


DTC P0791	Intermediate sensor circuit malfunction
DETECTION CONDITION	• Secondary gear revolution speed signal is not input after the following conditions are met and 4.5 s or more have passed. - D range selected - Engine coolant temperature 60 °C {140 °F} or more - Engine speed 500 rpm or more - Vehicle speed 40 km/h {25 mph} or more Diagnostic support note: • This is a continuous monitor (CCM). • The MIL illuminates if the TCM detects the above malfunction conditions during the first drive cycle. • The PENDING CODE is available if the TCM detects the above malfunction condition during the first drive cycle. • FREEZE FRAME DATA is available. • The AT warning light illuminates. • The DTC is stored in the TCM memory.
POSSIBLE CAUSE	• Intermediate sensor malfunction • Open circuit in wiring harness between intermediate sensor terminal B and TCM terminal 2L • Short to ground in wiring harness between intermediate sensor terminal B and TCM terminal 2L • Open circuit in wiring harness between intermediate sensor terminal A and AT main relay terminal A • Short to ground in wiring harness between intermediate sensor terminal A and AT main relay terminal A • Open circuit in wiring harness between intermediate sensor terminal C and body ground • Damaged connectors between intermediate sensor and TCM • TCM malfunction


STEP	INSPECTION		ACTION
1	VERIFY FREEZE FRAME DATA HAS BEEN RECORDED • Has the FREEZE FRAME DATA been recorded?	Yes	Go to the next step.
1		No	Record the FREEZE FRAME DATA on the repair order, then go to the next step.
2	VERIFY RELATED SERVICE INFORMATION AVAILABILITY • Verify related Service Bulletins and/or on-line repair information availability. • Is any related repair Information available?	Yes	Perform repair or diagnosis according to the available repair information. • If the vehicle is not repaired, go to the next step.
2		No	Go to the next step.
3	INSPECT INTERMEDIATE SENSOR CONNECTOR FOR POOR CONNECTION • Turn the ignition switch to the LOCK position. • Disconnect the intermediate sensor connector. • Inspect for poor connection (such as damaged/pulled-out pins, corrosion). • Is the connection normal?	Yes	Go to the next step.
3		No	Repair or replace the pin or connector, then go to Step 11.
4	INSPECT INTERMEDIATE SENSOR POWER CIRCUIT FOR OPEN CIRCUIT • Verify that the intermediate sensor connector is disconnected. • Turn the ignition switch to the ON position (engine off). • Inspect the voltage between intermediate sensor terminal A (wiring harness-side) and ground. • Is the voltage B+?	Yes	Go to Step 6.
4		No	Go to the next step.
5	INSPECT INTERMEDIATE SENSOR POWER CIRCUIT FOR SHORT TO GROUND • Turn the ignition switch to the LOCK position. • Inspect for continuity between intermediate sensor terminal A (wiring harness-side) and ground. • Is there continuity?	Yes	Go to the next step.
5		No	Repair or replace the wiring harness, then go to Step 11.
6	INSPECT INTERMEDIATE SENSOR GROUND CIRCUIT FOR OPEN CIRCUIT • Verify that the intermediate sensor connector is disconnected. • Inspect for continuity between intermediate sensor (wiring harness-side) terminal C and ground. • Is there continuity?	Yes	Go to the next step.
6		No	Repair or replace the wiring harness, then go to Step 11.
7	INSPECT TCM CONNECTOR FOR POOR CONNECTION • Disconnect the TCM connector. • Inspect for poor connection (such as damaged/pulled-out pins, corrosion). • Is the connection normal?	Yes	Go to the next step.
7		No	Repair or replace the pin or connector, then go to Step 11.
8	INSPECT SECONDARY GEAR REVOLUTION SPEED SIGNAL CIRCUIT FOR OPEN CIRCUIT • Disconnect the TCM connector and intermediate sensor connector. • Inspect for continuity between intermediate sensor terminal B and TCM terminal 2L. • Is there continuity?	Yes	Go to the next step.
8		No	Repair or replace the wiring harness, then go to Step 11.
9	INSPECT SECONDARY GEAR REVOLUTION SPEED SIGNAL CIRCUIT FOR SHORT TO GROUND • Verity that the intermediate sensor connector and TCM connector are disconnected. • Inspect for continuity between TCM terminal 2L and body ground. • Is there continuity?	Yes	Repair or replace the wiring harness, then go to the next step.
9		No	Replace the intermediate sensor, then go to the next step. (See INTERMEDIATE SENSOR REMOVAL/INSTALLATION [FS5A-EL].)
10	INSPECT INTERMEDIATE SENSOR • Inspect the intermediate sensor. (See INTERMEDIATE SENSOR INSPECTION [FS5A-EL].) • Is intermediate sensor normal?	Yes	Go to the next step.
10		No	Repair or replace the intermediate sensor, then go to the next step. (See INTERMEDIATE SENSOR REMOVAL/INSTALLATION [FS5A-EL].)
11	VERIFY TROUBLESHOOTING OF DTC P0791 COMPLETED • Make sure to reconnect all the disconnected connectors. • Clear the DTC from the memory using the WDS or equivalent. • Warm up engine. • Drive the vehicle under the following conditions for 4.5 s or more while monitoring PIDs. - Engine coolant temp (ECT PID): 60 °C {140 °F} or more - Drive in D range - Vehicle speed (VSS PID): 40 km/h {25 mph} or more • Is the PENDING CODE present?	Yes	Replace the TCM, then go to the next step. (See TCM REMOVAL/INSTALLATION [FS5A-EL].)
11		No	No concern is detected. Go to the next step.
12	VERIFY AFTER REPAIR PROCEDURE • Perform the "After Repair Procedure". (See AFTER REPAIR PROCEDURE [FS5A-EL].) • Are any DTCs present?	Yes	Go to the applicable DTC inspection.
12		No	DTC troubleshooting completed.