Code
P0758
MITSUBISHI
P — Powertrain
UD solenoid
Views:
UK: 7
EN: 16
RU: 16
AI status
Completed
Completed
100%
Causes
- Faulty UD shift solenoid (coil open, shorted, or intermittent)
- Damaged wiring harness or chafed/shorted wires to the solenoid
- Poor or corroded connector or pin terminal at the solenoid or TCM
- Low or contaminated automatic transmission fluid (ATF) causing solenoid sticking
- Faulty transmission control module (TCM/ECM) or internal driver transistor failure
- Poor ground or low battery/charging system voltage
Symptoms
- Check Engine Light or transmission fault lamp illuminated
- Transmission may stay in one gear, will not shift properly, or shifts harshly
- Delayed engagement, slipping, or stuck in limp/limitation mode
- Erratic shift behavior or inability to select certain gears
- Stored transmission-related codes in addition to P0758
What to check
- Read and record all transmission and engine codes, and freeze-frame data with a capable scan tool
- Inspect ATF level and condition; look for metal debris or contamination
- Visually inspect solenoid connector and wiring for damage, corrosion, or water intrusion
- Measure solenoid coil resistance at the connector with the harness disconnected
- Back-probe connector and check supply voltage and ground while cranking/running and while commanding the solenoid with scan tool
- Perform an active test/solenoid command via scan tool to observe response and compare to expected behavior
Signal parameters
- Coil resistance (typical range): ~10–30 ohms (manufacturer-specific — consult service data)
- Connector supply voltage: ~11–14 V (battery voltage present at relay/fused feed)
- Commanded voltage: 0–12 V (ON/OFF) or variable duty-cycle PWM when controlled by TCM
- Typical PWM frequency range: ~50–200 Hz for many modern shift solenoids (vehicle-specific)
- Operating current: roughly 0.5–1.5 A depending on coil resistance and voltage
Diagnostic algorithm
- Retrieve all DTCs and freeze-frame data. Note related codes and driving conditions.
- Inspect transmission fluid level and condition. Replace fluid/filter if contaminated or overdue.
- Visually inspect the UD solenoid connector and wiring for damage, corrosion, pin push-out, or water ingress. Repair as needed.
- With ignition OFF, disconnect the solenoid connector and measure coil resistance between solenoid terminals. Compare to manufacturer spec. Replace solenoid if open or out of range.
- With harness connected, back-probe the connector and measure battery voltage on the power feed and verify a good ground. Have someone command the solenoid ON/OFF with a scan tool and observe voltage change or PWM duty.
- Check for continuity between the solenoid harness and the TCM pin; check for shorts to ground or battery. Repair wiring harness faults.
- Perform an active solenoid command with a scan tool and verify hydraulic/shift response. If commanded activation does not change state but wiring/voltage are correct, replace solenoid.
- If wiring and solenoid test good, inspect/replace valve body or check TCM operation. Swap with a known-good solenoid (if available) to confirm.
- After repair, clear codes and perform test drive under conditions that previously set the code. Re-scan to confirm code does not return.
Likely causes
- Defective UD shift solenoid
- Open or short in solenoid wiring or corroded connector
- Contaminated/old transmission fluid causing solenoid sticking
- Intermittent connection at TCM or bad ground
Fault status
Status
P0758 — Shift Solenoid 'UD' Electrical: Detected open/short/incorrect response on the UD shift solenoid circuit. Inspect solenoid, wiring/connectors, ATF condition, and TCM.
Repair difficulty: Medium
Diagnostic time: 1-2 hours
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