At each power up the transfer case shift control module runs a self test on the following:
• | EEPROM Checksum |
• | ROM Checksum |
• | RAM Checksum |
• | RAM Malfunction |
• | Critical operational parameters stored in EEPROM have failed Checksum test indicating invalid data. |
• | Masked ROM code has failed Checksum test indicating that masked ROM data is not valid. |
• | ROM code has failed Checksum test indicating that ROM data is not valid. |
• | One or more ROM locations have failed operational test indicating that some portions of RAM are not functional. |
The condition for setting the DTC is not present and a momentary loss of battery power at the battery positive voltage circuit, CKT 40.
The number below refers to the step number on the diagnostic table.
Step | Action | Yes | No |
---|---|---|---|
Schematic Reference: Transfer Case Control Schematics | |||
1 |
Important: Check the transfer case shift control module
for DTCs. The transfer case shift control module is not a class 2 device. DTCs are
displayed on the transfer case shift control switch. Use the following four steps
to obtain DTCs.
Did you perform the Diagnostic System Check-Transfer Case? | Go to Step 2 | |
Replace the transfer case shift control module. Refer to Transfer Case Shift Control Module Replacement . Did you complete the replacement? | Go to Step 3 | -- | |
3 |
Does the DTC reset? | Go to Step 2 | System OK |