U1045: Hybrid Traction Motor Module Lost Communication
The U1045 code indicates that the Powertrain Control Module (PCM) or Vehicle Control Module (VCM) has detected a loss of communication or invalid data on the SCP (Standard Corporate Protocol) J1850 VPW bus from the Traction Motor Control Module (TCM/TMCM). This fault is exclusive to hybrid and electric vehicles, such as the Ford Escape Hybrid, Fusion Hybrid, and C-Max Energi, where the high-voltage traction motor is managed by a dedicated module that reports its status via the SCP network.
1. Commonly Affected Makes
2. Most Common Causes
- Faulty or internally failed Traction Motor Control Module (TMCM)
- Open circuit, short to ground, or short to battery on the SCP bus (+/-) wiring to the TMCM
- Loose, corroded, or damaged connector at the TMCM
- Loss of power (B+) or ground to the TMCM
- Damaged or missing SCP bus termination resistors
- Software error in the PCM/VCM or TMCM requiring reprogramming
3. Symptoms You Will Notice
- Check Engine Light or Hybrid System Warning Light illuminated
- Reduced power or limp mode, possible inability to start or move
- Loss of hybrid system functionality, engine may run but electric assist is disabled
4. Step-by-Step Diagnosis
Scan for all stored codes and freeze frame data; note any related U-codes.
Visually inspect the TMCM connector and wiring for damage, corrosion, or loose pins.
Measure voltage and ground at the TMCM connector; verify battery voltage and good ground.
Test SCP bus communication lines (typically two wires) for continuity, shorts, and proper resistance (should be ~60 ohms with termination resistors).
If wiring and power are okay, suspect a faulty TMCM or PCM/VCM; attempt reprogramming before replacing modules.
5. Frequently Asked Questions
Is it safe to drive?▼
No, it is not safe to drive. The vehicle may enter limp mode or lose hybrid functionality, potentially causing a loss of power or unexpected shutdown. Have the vehicle towed to a repair facility.
How much does it cost to fix?▼
Repair costs vary widely depending on the root cause. A simple wiring repair may cost $100–$300, while replacing a TMCM can range from $800 to $2,500 including parts and labor. Reprogramming may add $100–$200.