P0725
P0725-ENGINE SPEED SENSOR CIRCUITWhen Monitored:
Continuously every 7 msec with the ignition on and engine running.
Set Condition:
This DTC will set when the calculated engine speed is less than 390 RPM, or greater than 8000 RPM, for the period of 2.0 seconds. The PCM will place the Transmission in Limp-in after 10.0 seconds of repeated problem identification.
Note: This is not a Transmission Input Speed Sensor DTC.
Possible Causes
- RELATED ENGINE DTC'S PRESENT
- POWERTRAIN CONTROL MODULE
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Testing and Inspection
Theory of Operation
The Transmission Control System calculates the engine RPM from the engine speed sensor signal transmitted from the Engine Control System over the controllers internal bus. The calculated engine RPM is compared to a minimum and a maximum value. Note: Due to the integration of the Powertrain Control Module (PCM) and Transmission Control Module (TCM), bus communication between the modules is internal and unserviceable.
Diagnostic Test
1. RELATED ENGINE DTCS PRESENT
Note: This is not a Transmission Input Speed Sensor DTC. Ignition on, engine not running.
With the scan tool, read all Engine DTC's. This includes any active or stored or one trip DTCs.
Are there any engine RPM related DTCs present?
Yes >>Refer to the Powertrain category and perform the appropriate symptom.
Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1. Verification Tests
No >>Go To 2
2. VERIFY IF THE DTC IS CURRENT
Ignition on, engine not running.
With a scan tool, read and record all EATX DTC EVENT DATA.
With the scan tool, erase all active and stored transmission DTCs.
Note: it may be necessary to perform a battery disconnect with the scan tool to clear EATX DTC EVENT DATA.
Using the EATX DTC EVENT DATA, duplicate the conditions in which the original DTC set.
With the scan tool, read transmission and engine DTCs.
Note: Refer to all engine DTCs first in the following question.
Pick the answer below that best describes your findings, (this includes one trip failures).
Transmission DTC P0725 set
Using the schematics as a guide, check the Powertrain Control Module (PCM) terminals for corrosion, damage, or terminal push out. Pay particular attention to all power and ground circuits. If no problems are found, replace the PCM per the Service Information. With the scan tool, perform QUICK LEARN.
Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1.
Engine DTC set
Refer to the Driveability category and perform the appropriate symptom.
Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1.
No DTC set at all Go To 3
3. INTERMITTENT WIRING AND CONNECTORS
The conditions necessary to set this DTC are not present at this time.
Using the schematics as a guide, inspect the wiring and connectors specific to this circuit.
Wiggle the wires while checking for shorted and open circuits.
With the scan tool, check the EATX DTC EVENT DATA to help identify the conditions in which the DTC was set.
Were there any problems found?
Yes >>Repair as necessary.
Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1.
No >>Test Complete.