Code
P1757
PONTIAC
P — Powertrain
Governor Pressure Above 3 PSI When Request Is 0 PSI
Views:
UK: 21
EN: 39
RU: 26
AI status
Completed
Completed
100%
Causes
- Internal hydraulic pressure present in governor circuit when controller requests zero pressure
- Faulty governor pressure sensor or sender producing incorrect reading
- Stuck or leaking pressure regulator/relief valve or valve-body spool
- Faulty pressure control/flow solenoid or its bleed path
- Wiring harness or connector fault between sensor/solenoid and PCM/TCM
- Contaminated or low transmission fluid affecting valve operation
Symptoms
- Transmission may hold higher than expected line pressure at idle or when no pressure is requested
- Erratic or harsh shift engagement, delayed or abnormal shifting
- Transmission diagnostic lamp or MIL illuminated
- Stored P1757 and possibly other transmission codes
- Possible reduced performance mode (limp-in) depending on vehicle
What to check
- Read freeze-frame and live data with a scan tool: compare governor pressure actual vs governor pressure request
- Confirm PCM/TCM request value is 0 while actual pressure is above 3 PSI
- Visually inspect transmission fluid level, color and smell (burnt fluid)
- Inspect wiring and connectors for the governor pressure sensor and pressure control solenoids for corrosion, damage, or poor connections
- If available, hook a mechanical transmission pressure gauge to the governor port and verify actual hydraulic pressure
- Check for related DTCs (solenoids, pressure sensors, speed sensors) that can narrow the fault
Signal parameters
- Expected governor pressure when request = 0: ≤ 3 PSI
- Actual governor pressure in this fault: > 3 PSI (measured value may vary by model)
- Governor pressure sensor output typically low voltage at near-zero pressure (manufacturer-specific; roughly 0–1 V at very low pressure on many systems)
- When request increases, governor pressure should rise proportionally (scan tool should show correlated change)
Diagnostic algorithm
- Retrieve and record all stored transmission codes and freeze-frame data, then clear codes.
- Use a scan tool to monitor governor pressure requested vs actual with the engine running and transmission in the condition that triggered the code. Reproduce if possible.
- If the scan tool shows actual pressure > 3 PSI while request = 0, perform a visual inspection of wiring/connectors for the governor pressure sensor and pressure control solenoids; repair any issues.
- Check transmission fluid level and condition; correct level and replace fluid/filter if severely contaminated.
- Install a mechanical pressure gauge at the governor/specified test port to confirm hydraulic pressure independent of the sensor. Compare mechanical reading to scanner value to identify sensor vs hydraulic fault.
- If mechanical pressure is high, inspect valve body components: check for stuck regulator/relief valve, clogged bleed passages, or worn valve bores; clean or repair valve body as required (service kit or replacement).
- If mechanical pressure is low/normal but sensor output is high, test and replace the governor pressure sensor or repair its circuit (check for short to voltage).
- If a pressure control solenoid or check valve is suspected, test solenoid resistance/operation and replace if out of spec or leaking internally.
- After repairs, clear codes and road-test to confirm the governor pressure follows request and that P1757 does not return.
Likely causes
- Stuck valve in valve body (regulator/bleed/relief) that prevents pressure from collapsing to ≤3 PSI
- Failed or miscalibrated governor pressure sensor (wrong output at low pressure)
- Shorts or opens in sensor/solenoid wiring or poor connector pins causing false sensor value
- Pressure control solenoid (or its check/bleed path) stuck closed or leaking internally
- Debris or varnish in valve body preventing proper bleed-down of governor circuit
- Incorrect fluid level or severely degraded fluid changing hydraulic behavior
Fault status
Status
Governor pressure above 3 PSI when request is 0 PSI — PCM/TCM detected excessive hydraulic pressure or incorrect sensor signal in the governor circuit and set DTC P1757.
Repair difficulty: Medium
Diagnostic time: 2-6 hours
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