OBD-II Diagnostic Trouble Code
P1638
TCM Internal - CAN 1 Ram Performance
P
Powertrain
engine / trans
engine / trans
1
Mfr
manufacturer code
manufacturer code
6
Computer & output circuits
38
TCM Internal - CAN 1 Ram Performance
Severity · general guide
Moderate
Fix soon — usually won't strand you
Code type
Jeep
System
Powertrain
Model
Grand Cherokee
Years
2011