2007 Grand Cherokee WK Factory Service Manual 21 - TRANSMISSION AND TRANSFER CASE

P2784-INPUT SPEED SENSOR 1/2 CORRELATION





For a complete wiring diagram Refer to Section 8W

Theory of Operation


The Input Speed Sensors 1 and 2 (N2 - N3) will report the same speed in 2nd, 3rd and 4th gears. If the Input Speed Sensor 1 and 2 signals are not the same in these gears, the DTC will set.



Possible Causes
 
INTERNAL TRANSMISSION
 
TRANSMISSION CONTROL MODULE
 


Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - NAG1 - STANDARD PROCEDURE)



Diagnostic Test

1. CHECK FOR SPEED SENSOR OR SENSOR SUPPLY VOLTAGE DTCS

With the scan tool, check for other transmission DTCs.

Are any Input Speed Sensor and/or Sensor Supply Voltage DTCs present?

Yes


No

2. CHECK TO SEE IF INPUT SENSOR MISMATCH IS CURRENT

NOTE: If the TCM detects and stores a DTC, the TCM also stores the vehicles operating conditions under which the DTC originally set and is located in scan tool under Environmental Data. Before erasing any stored DTCs, record any available data to assist in duplicating the conditions in which the DTC originally set.


With the scan tool, record the Environmental Data and erase Transmission DTCs.
Using the Environmental Data recorded earlier, test drive the vehicle while trying to duplicate the conditions in which the DTC originally set.

Did the DTC P2784-INPUT SPEED SENSOR 1/2 CORRELATION reset?

Yes


No

3. INTERNAL TRANSMISSION

Turn the ignition off to the lock position.
Remove the Transmission Oil Pan and inspect for debris, a plugged Transmission Oil Filter, or any sign of an internal transmission problem.

Is there any debris, plugged Transmission Oil Filter, or any sign of an internal transmission problem?

Yes


No

4. 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 wiring and connectors while checking for any possible open or shorted circuits.
Check for any Service Information Tune-ups or Technical Service Bulletins that may apply.

Were there any problems found?

Yes


No