Jeep Grand Cherokee WK. Manual — part 1302

U0100–LOST COMMUNICATION WITH ECM/PCM (CONTINUED)

For the Transmission circuit diagram (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - NAG1 - SCHE-
MATICS AND DIAGRAMS)

For a complete wiring diagramRefer to Section 8W

Theory of Operation

Some controllers communicate with other controllers over the CAN C bus. The Shifter controller continuously mon-
itors the bus activity and receives the messages it needs. The CAN C bus is also used to communicate transmis-
sion MIL status to the Engine Controller.

Refer to 8-ELECTRICAL/ELECTRONIC CONTROL MODULES - DIAGNOSIS AND TESTING for diagnostic pro-
cedures and for further possible causes.

21 - 18

AUTOMATIC TRANSMISSION NAG1 - SHIFTER DIAGNOSTICS

WK

U0121–LOST COMMUNICATION WITH ANTI-LOCK BRAKE MODULE

WK

AUTOMATIC TRANSMISSION NAG1 - SHIFTER DIAGNOSTICS

21 - 19

U0121–LOST COMMUNICATION WITH ANTI-LOCK BRAKE MODULE (CONTINUED)

For the Transmission circuit diagram (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - NAG1 - SCHE-
MATICS AND DIAGRAMS)

For a complete wiring diagramRefer to Section 8W

Theory of Operation

Some controllers communicate with other controllers over the CAN C bus. The ABS controller continuously monitors
the bus activity and receives the messages it needs. The CAN C bus is also used to communicate transmission MIL
status to the Engine Controller.

Refer to 8-ELECTRICAL/ELECTRONIC CONTROL MODULES - DIAGNOSIS AND TESTING for diagnostic pro-
cedures and for further possible causes.

21 - 20

AUTOMATIC TRANSMISSION NAG1 - SHIFTER DIAGNOSTICS

WK

U0141–LOST COMMUNICATION WITH FRONT CONTROL MODULE

WK

AUTOMATIC TRANSMISSION NAG1 - SHIFTER DIAGNOSTICS

21 - 21