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DTC P0791 [FS5A-EL]

id050221810600

DTC P0791 | Intermediate sensor circuit malfunction
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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

Diagnostic procedure

STEP | INSPECTION | ACTION
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1 | VERIFY FREEZE FRAME DATA HAS BEEN RECORDED • Has the FREEZE FRAME DATA been recorded? | Yes | Go to the next step.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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].)
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.
No | DTC troubleshooting completed.