DODGE Code P128E: Causes, Symptoms, and Solutions
Meaning of Code P128E
P128E code on a Dodge vehicle indicates a communication or operational issue between the Powertrain Control Module (PCM) and the Transmission Control Module (TCM). The PCM detects that the TCM is not responding according to the manufacturer’s technical specifications, which disrupts transmission management.
Possible Causes
- TCM Failure:
- The Transmission Control Module is damaged or has an internal defect.
- Electrical Issues:
- Damaged TCM wiring harness (cut wires, short circuits, or degraded insulation).
- Faulty Connections:
- TCM connectors are loose, corroded, or have broken/bent pins.
- Software Error:
- Incorrect calibration of the TCM or PCM requiring an update.
Common Symptoms
- Engine light on (“Check Engine” or “Service Engine Soon”).
- Transmission malfunctions:
- Limp mode activation (stuck in one gear).
- Irregular or delayed gear shifts.
- Reduced acceleration or unstable idle.
Repair Procedures
- Visual Inspection:
- Examine the TCM wiring harness and connectors.
- Look for corroded pins, exposed wires, or physical damage.
- Electrical Tests:
- Use a multimeter to check:
- TCM power supply voltage and ground.
- Circuit continuity between the TCM and PCM.
- Identify short circuits or open circuits.
- Software Diagnostics:
- Use a Dodge diagnostic tool (e.g., WiTECH) to:
- Read additional error codes.
- Check for available software updates.
- Test PCM-TCM communication.
- Replacement or Reset:
- If the TCM is faulty, replace it and reprogram it with factory settings.
- Clean or replace damaged connectors.
Technical Information
- TCM Location: Typically located near the transmission or in the engine compartment (refer to the service manual).
- Affected Models: Often observed on Dodge RAM, Charger, Durango, and other vehicles equipped with recent automatic transmissions.
Key Tips
- Reset the PCM/TCM after repair to clear adaptations.
- Consult a professional if the problem persists, especially for complex software diagnostics.
Estimated Cost:
- TCM Replacement: €300 to €800 (part + labor).
- Wiring Harness Repair: €100 to €300.
Note: Costs vary depending on the model and TCM access (sometimes requiring disassembly). Prefer original or certified parts.
If in doubt, always perform a road test after repair to confirm the symptoms have disappeared.