Diagnostic Instructions
DTC Descriptor
DTC P0881: TCM Power Input Signal Performance
Circuit/System Description
The transmission control module (TCM) requires continuous battery voltage to operate. The TCM monitors the battery voltage.
Conditions for Running the DTC
Engine speed is greater that 500 RPM.
Conditions for Setting the DTC
Condition 1
The DTC sets when the TCM detects battery B+ voltage below 6.5 V for 1 second.
Condition 2
DTC sets when the TCM detects a variation in battery B+ voltage greater than 4 V for a number of samples within 1 second.
Action Taken When the DTC Sets
| • | The TCM does not request the ECM to illuminate the malfunction indicator lamp (MIL). |
| • | DTC P0881 is stored in TCM history. |
| • | The transmission goes into hydraulic default. If the transmission was in a forward range, the transmission will shift to first, third or fifth range. If the transmission was in reverse or neutral, the transmission will shift to reverse or neutral. |
| • | The TCM inhibits torque converter clutch (TCC) engagement. |
| • | Main modulation is disabled. |
Conditions for Clearing the DTC
DTC P0881 is a Type C DTC.
Diagnostic Aids
| • | A defective vehicle battery may allow this code to set. |
| • | A defective vehicle charging system may allow this code to set. |
| • | You may have to drive the vehicle in order to experience a condition. |
| • | Vehicle accessories imposing a large electrical load on the battery circuit could cause this DTC to set. |
| • | Although this DTC could indicate an internal voltage condition within the TCM, in most cases, the TCM is not at fault. Investigate thoroughly prior to replacing the TCM. |
Reference Information
Schematic Reference
Automatic Transmission Controls Schematics
Connector End View Reference
Component Connector End Views
Description and Operation
Electrical Information Reference
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
- Engine running, accessories OFF, measure and record the battery voltage at the battery terminals. The reading should be between 12.6-15 V.
- Observe the scan tool TCM ignition voltage parameter. The reading should be between 12.6 and 15 V.
- Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
Circuit/System Testing
Note: You must perform the Circuit/System Testing first.
- Ignition OFF, disconnect the harness connector at the TCM.
- Ignition OFF, test for less than 3 ohms between ground circuit terminal 9 and battery ground, and between ground circuit terminal 69 and battery ground.
| ⇒ | If greater than the specified range, repair the affected ground circuit. |
- Ignition OFF, verify that a test lamp illuminates between battery B+ circuit terminal 10 and ground, and battery B+ circuit terminal 70.
| ⇒ | If the test lamp does not illuminate, repair the affected B+ circuit. |
| ⇒ | If circuits test normal, replace the TCM. |
Repair Instructions
Perform the
Diagnostic Repair Verification after completing the diagnostic procedure.
Repair Verification
If another DTC is present, refer to
Diagnostic Trouble Code (DTC) List - Vehicle and perform the appropriate diagnostic procedure.
