Transmission ECU - Speed Sensor Fault

Volvo CE Heavy Equipment Warning DriveSystem

Model: Volvo L120H Wheel Loader | Code: VOLVO SA-01

Applicable Systems
EC220 Excavator

Symptoms

Transmission speed sensor signal loss; gear selection may be limited to emergency mode.

Possible Causes

  • Transmission speed sensor faulty
  • Sensor wiring harness damage
  • Sensor air gap incorrect

Troubleshooting Steps

  1. Step 1: Check transmission speed sensor at housing
    Sensor mounted correctly
  2. Step 2: Measure sensor resistance (800-1200 ohm)
    Resistance within range
  3. Step 3: Check sensor air gap (0.5-1.0mm)
    Air gap within specification
  4. Step 4: Inspect sensor wiring for damage
    Wiring intact, no chafing
  5. Step 5: Replace speed sensor if resistance out of range
    New sensor signal present

How to Reset

Clear via Volvo Tech Tool after sensor replacement.

Common Replacement Parts

  • Transmission Speed Sensor P/N: VOE14567890

Frequently Asked Questions

  • Q: What happens when transmission speed sensor fails?

    Transmission may default to limp mode (2nd gear only) or emergency mode with limited speed. Safe for transport to service but not for work.

Source: volvo fault codes reference

Category: Heavy Equipment