Circuit Description
DTC P1760 will set if an abnormal power-down sequence has occurred. An abnormal power-down sequence condition means the transmission control module (TCM) has lost battery positive voltage circuit, supply voltage, before it has finished saving information from that drive cycle. This process is usually completed in less than 10 seconds.
DTC P1760 is a type C DTC.
Conditions for Running the DTC
| • | The components are powered and ignition voltage is greater than 9.0 volts and less than 18 volts. |
| • | There is a loss of TCM supply voltage before the drive cycle data is saved. |
Conditions for Setting the DTC
DTC P1760 sets during the next ignition cycle if the TCM loses supply voltage less than 10 seconds after the ignition voltage has been turned off.
Action Taken When the DTC Sets
| • | The TCM does not illuminate the malfunction indicator lamp (MIL). |
| • | DTC P1760 will be stored in TCM history. |
| • | There is a loss of adaptive information for the drive cycle. Revert to previous adaptive settings. |
| • | The TCM inhibits torque converter clutch (TCC) engagement. |
Conditions for Clearing the DTC
A scan tool can clear the code from TCM history. The TCM automatically clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without failure.
Diagnostic Aids
| • | Inspect the wiring for poor electrical connections at the TCM. Look for the following conditions: |
| - | A bent terminal |
| - | A backed-out terminal |
| - | A damaged terminal |
| - | Poor terminal tension |
| - | A chafed wire |
| - | A broken wire inside the insulation |
| • | When diagnosing for an intermittent short or open, massage the wiring harness while watching the test equipment for a change. |
| • | You may have to drive the vehicle in order to experience a condition. |
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
This step tests the system voltage.
-
This step test the vehicle charging system.
-
This step tests the wiring harness for opens or shorts.
Step | Action | Value | Yes | No |
|---|---|---|---|---|
Schematic Reference: Automatic Transmission Controls Schematics | ||||
1 | Did you perform the Diagnostic System Check - Automatic Transmission? | -- | Go to Step 2 | |
Important: Before clearing the DTC, use the scan tool in order to record the Freeze Frame and Failure Records for reference. The Clear Info function will erase the data. Important: If other DTCs are present, refer to the applicable diagnostic tables before continuing. Is voltage within the specified amount? | B+ | Go to Step 3 | Go to Battery Inspection/Test in Engine Electrical | |
3 | Start the engine and warm to normal operating temperature. Is the Alternator/Check Engine lamp ON? | -- | Go to Charging System Test in Engine Electrical | Go to Step 4 |
Is the voltage within the specified range? | 13-15 V | Go to Step 5 | Go to Charging System Test in Engine Electrical | |
Is voltage within the specified amount of B+ voltage? | 0.5 V | Go to Step 6 | Go to Step 7 | |
6 |
Did you complete the repair? | -- | Go to Step 8 | -- |
7 |
Important: In most cases, the TCM is not at fault. Investigate thoroughly before replacing the TCM. Replace the TCM. Refer to Transmission Control Module Replacement . Did you complete the replacement? | -- | Go to Step 8 | -- |
8 | Perform the following procedure in order to verify the repair:
Has the test run and passed? | -- | System OK | Go to Step 1 |
