OBD-II Diagnostic Trouble Code
P1690 — Wastegate Control Boost Pressure Out of Range
P1690 is a manufacturer-specific code that commonly means boost pressure is out of range for the wastegate control command, so the ECM sees more or less boost than expected. Meaning can vary by OEM.
Severity 4/5
Truck-relevant
Stop within 50 mi
Severity
Stop within 50 mi
Wastegate Control Boost Pressure Out of Range
Code
P1690
Category
Powertrain
Subsystem
Turbo
Truck-relevant
Yes
What this means for truckers
P1690 (Wastegate Control Boost Pressure Out of Range) — common on PACCAR MX-13 and Detroit DD15. The ECM commanded a certain wastegate position, didn't get the corresponding boost. Causes: stuck wastegate actuator, leak in vacuum/electric control line, or failed wastegate solenoid. Replace solenoid ($150-400) before wastegate assembly ($1,200+).
Before you replace parts — try this first
P1690 on the Turbo system is most often sticking wastegate or actuator — not a dead part. On commercial diesels especially, work these in order before spending money on parts:
- Confirm the symptoms. Match what your truck is doing to the Symptoms section below. If the code is set but the symptoms are not there, clear the code and re-test after a drive cycle — it may not return.
- Clean and dry the sensor connector. Water, road salt, or oil seeping into a connector is the #1 fake sensor failure. Disconnect, look for green corrosion or moisture, spray with electrical contact cleaner, dry, reseat. Many faults clear here for $0.
- Inspect the wiring harness. Trace the wire from the sensor toward the ECM — look for chafing against the engine block, melted insulation near the turbo or exhaust, or pinch points where a clamp has rubbed through.
- Test the sensor before swapping it. Most Common Causes (below) list the expected voltage or resistance range — a $20 multimeter saves a $300 sensor swap that does not fix the problem.
- Only then, replace the part. Use the OEM or a tier-1 aftermarket. Cheap sensors throw the same code in two weeks.
Symptoms
Low power or derate and black smoke when boost is low, or surging and overboost derate when boost is high, plus a check-engine light. Some trucks also have unusual turbo noise.
Common causes
- CommonSticking wastegate or actuator ($250–$900)
- CommonFaulty wastegate control solenoid or leaking actuator air line ($100–$400)
- OccasionalBoost leak in charge air cooler or hoses ($150–$1200)
- OccasionalFaulty boost pressure sensor ($150–$400)
- RareTurbocharger failure ($2000–$5000)
How to fix
Check actual vs commanded boost with a scan tool
When to use: First step
Pressure-test the charge air system
When to use: When boost is low
Test wastegate actuator, control solenoid and supply line
When to use: When boost is out of range in either direction
Replace the turbo or wastegate
When to use: When the turbo is damaged
Affects most
No specific vehicle pattern found in our complaint database. This code can appear on any vehicle that supports OBD-II diagnostics.
Related
- → Browse all DTC trouble codes
- → Decode a VIN to check codes for your truck
- → Owner-operator maintenance guides
- → P1607 — Internal Control Module Performance
- → P1635 — 5 Volt Reference 1 Circuit
- → P1638 — 5 Volt Reference 2 Circuit
- → P1654 — AC Refrigerant Pressure Switch Performance
- → P1693 — Glow Plug Control Module Communication Lost
Frequently Asked Questions
Can I drive with code P1690?
Drive with caution. P1690 is severity 4 — stop within ~50 miles. Most commercial diesel codes at this severity (turbo, fuel rail, transmission solenoid) can damage adjacent expensive components if left unrepaired. Get to a service location before highway-speed loads.
How much does it cost to fix P1690 on a commercial truck?
Total repair cost ranges $100–$5000 depending on the root cause. The cheapest fix is usually the first one listed below — Sticking wastegate or actuator — which is also the most common. On commercial trucks the cost is usually higher than passenger vehicles due to part availability and shop labor rates ($120–185/hour at most truck shops, vs $90–130 at general auto shops). DIY-capable fixes (sensors, hoses, filters) are at the low end; major component replacements (turbo actuator, high-pressure fuel pump, transmission solenoid pack) are at the high end. Always diagnose with a scan tool BEFORE replacing parts — guessing wrong on a $1,500 turbo actuator when the actual issue was a $30 boost hose is a common expensive mistake.
Will P1690 fail a DOT inspection?
P1690 itself doesn't automatically fail an inspection, but if the truck is in reduced-power mode (limp mode) at the time of inspection, it WILL be flagged. Most inspectors will note the check engine light but pass the truck if it's running and performance is normal. Fix it before a Level 1 inspection regardless.
What's the difference between P1690 and related codes?
P1690 is closely related to: P1607 (Internal Control Module Performance), P1635 (5 Volt Reference 1 Circuit), P1638 (5 Volt Reference 2 Circuit), P1654 (AC Refrigerant Pressure Switch Performance). These codes share the same subsystem (turbo) and often appear together. If you see this code, scan for the full code list — fixing the root cause usually clears multiple companion codes at once. If only P1690 is set without the companions, the issue is more isolated.
How do I prevent P1690 from coming back after a repair?
For P1690 (Wastegate Control Boost Pressure Out of Range), prevention centers on the turbo system. Inspect boost piping at every PM service. Replace silicone boost hoses preventively at 250K miles. Run quality diesel fuel (low ash, high cetane) to keep VGT vanes from carbon-locking. After repair, drive 30 miles of mixed-load conditions to let the ECM relearn boost calibration.