Code
P0759
GWM
P — Powertrain
- Malfunction of solenoid switch B
Views:
UK: 0
EN: 4
RU: 7
AI status
Completed
Completed
100%
Causes
- Open or shorted wiring in the solenoid B circuit
- Poor or corroded connector at solenoid or TCM
- Failed shift solenoid B (stuck, shorted or open)
- Low, dirty or contaminated transmission fluid
- Faulty valve body or internal hydraulic blockage
- Faulty Transmission Control Module (TCM) or software issue
Symptoms
- Check Engine / Transmission Warning lamp illuminated
- Harsh, delayed, or erratic shifting
- Transmission may be stuck in limp/ fail-safe mode (reduced gear selection)
- Gear hunting, slipping, or inability to engage certain gears
- Noises from the transmission or unusual shift feel
What to check
- Read freeze frame data and full DTC list with a capable scan tool; note other transmission codes
- Visually inspect wiring and connectors for damage, corrosion, loose pins, or water ingress at solenoid and TCM
- Check transmission fluid level and condition (colour, odour, contamination)
- Use scan tool to command/activate solenoid B and observe live data / shift response
- Measure solenoid coil resistance at the connector (compare to GWM spec)
- Check voltage supply and ground at the solenoid circuit with key ON/engine running while activating
Signal parameters
- Typical DC coil resistance (dependent on model) — commonly in the range ~5–40 Ω; check GWM service manual for exact spec
- Activation signal: PWM from TCM when commanded; frequency often tens to low hundreds of Hz (varies by model)
- Command control: variable duty cycle (0–100%) depending on requested pressure control
- Expected circuit voltage with key ON (ignition): battery voltage at the power feed to solenoids
- Expected ground continuity to TCM when solenoid not energized; check for transient voltages during activation
Diagnostic algorithm
- Verify the code: Clear DTCs, perform a test drive and re-scan to confirm P0759 is repeatable.
- Capture freeze-frame and live data for transmission parameters, solenoid command status and actual gear state.
- Visually inspect the solenoid connector and harness for corrosion, damage or poor connections; repair as needed.
- Check ATF level and condition; top or replace fluid/filter if dirty or contaminated per service interval.
- With engine off, disconnect solenoid connector and measure coil resistance between the solenoid terminals; compare to spec.
- With connector connected, backprobe the power and control wires; verify battery voltage on feed and switching/PWM signal on control while commanding solenoid with scan tool.
- Perform continuity checks from the solenoid connector back to the TCM to look for opens or shorts to ground/power.
- If wiring and voltage checks pass but solenoid resistance is out of spec or solenoid does not actuate, replace solenoid B (or valve body assembly if solenoids are integral).
- If solenoid and wiring are good, consult manufacturer procedures for TCM testing or reflashing; replace TCM only after exhausting harness/solenoid/valve body checks.
- After repairs, clear codes and road test to verify proper operation and that P0759 does not return.
Likely causes
- Wiring damage (pinched, chafed, or disconnected connector) to solenoid B
- Corroded/loose connector at the solenoid or at the TCM
- Failed/shorted shift solenoid B
- Low or degraded ATF causing solenoid sticking or poor valve movement
Fault status
Status
Malfunction of solenoid switch B (Shift Solenoid B circuit fault detected by TCM).
Repair difficulty: Medium
Diagnostic time: 1.0 - 3.0 hours
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