Circuit Description
The external watchdog will be triggered. If the external watchdog does not run out after 30 milliseconds then the fault will be detected.
Conditions for Setting the DTC
| • | The system voltage is too high or too low. |
| • | The transmission input voltage is too high or too low. |
Action Taken When the DTC Sets
| • | The malfunction indicator lamp (MIL) will illuminate. |
| • | The transmission control module (TCM) will record operating conditions at the time the diagnostic fails. This information will be stored in the Failure Records buffer. |
| • | Adopt Emergency/Substitute mode and constant 4th gear. |
| • | After ignition OFF/ON, 3rd gear by hydraulic control, and the positions P, R, and N are also possible. |
| • | The power supply is cut off to the EDS valve. |
Conditions for Clearing the MIL/DTC
| • | The MIL will turn OFF when the malfunction has not occurred after 3 ignition cycles. |
| • | A history DTC will clear after 40 consecutive warm-up cycles without a fault. |
| • | Clear the DTCs with a scan tool. |
Diagnostic Aids
When DTC P1606 sets, the possible cause of the fault could be the TCM.
Step | Action | Yes | No |
|---|---|---|---|
1 | Did you perform the Diagnostic System Check-Automatic Transmission? | Go to Step 2 | |
2 |
Does the scan tool display DTC 1606? | Go to Step 3 | Go to Diagnostic Aids |
3 | Inspect the EF30 or F10 fuse for an open. Was a condition found? | Go to Step 4 | Go to Step 5 |
4 | Replace the fuse, as necessary. Is the action complete? | System OK | -- |
5 |
Was a condition found? | Go to Step 10 | Go to Step 6 |
6 | Inspect the wiring harness for a short to the battery between fuses EF30 or F10, and the TCM terminals B3, C15, or C16. Was a condition found? | Go to Step 10 | Go to Step 7 |
7 | Inspect the wiring harness for an open or short to the battery between TCM terminals B12, B13, and G104. Was a condition found? | Go to Step 10 | Go to Step 8 |
8 | Inspect the wiring harness for an open or short to the battery between terminals B12, B13, and G103. Was a condition found? | Go to Step 10 | Go to Step 9 |
9 | Replace the TCM. Refer to Transmission Control Module Replacement . Is the replacement complete? | Go to Step 11 | -- |
10 | Repair the wiring harness. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | System OK | -- |
11 |
Does the scan tool indicate that this diagnostic has ran and passed? | Go to Step 12 | Go to Step 2 |
12 | Check if any DTCs are set. Are any DTCs displayed that have not been diagnosed? | System OK |
