Refer to
Cellular Telephone Module (w/UV8)
and
Cellular Telephone Microphone (w/UV8)
.
Circuit Description
The EEPROM checksum error detection is handled inside the module. No external circuits are involved.
Conditions for Running the DTC
The module runs the program to detect a checksum error after each power up. The only requirements are voltage and ground. This program runs even if the voltage is out of the valid operating range.
Conditions for Setting the DTC
The module retains an inverse copy of the digital value stored in certain blocks of memory in the EEPROM. The module then reads the information from those certain blocks and adds the stored inverse value to the current value. If they do not equal 0, the module sets this DTC.
Action Taken When the DTC Sets
The module reverts to base operation values programmed for those blocks of data that have failed the checksum test.
Conditions for Clearing the DTC
The DTC clears when the module runs a successful check sum test of the EEPROM.
Diagnostic Aids
| • | This DTC may be stored as a history DTC with out affecting the operation of the module. If stored only as a history DTC and not retrieved as a current DTC, do not replace the module. |
| • | If this DTC is retrieved as both a current and history DTC, replace the module. |
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Did you perform Diagnostic System Check - Cellular Telephone ? | -- | Go to Step 2 | |
2 |
Is the DTC current? | -- | Go to Step 3 | Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems |
3 | Replace the cellular telephone module. Refer to Radio Frequency Booster and Bracket Assembly Replacement . Did you complete the replacement? | -- | Go to Step 4 | -- |
4 |
Does the DTC reset? | -- | Go to Step 2 | System OK |
