C0749 Engine Trouble Code
What is C0749?
With C0749, you may drive for several weeks with a malfunctioning MAF sensor, but expect decreased fuel economy and eventual stalling. Shop replacement costs $240–$400 depending on vehicle. The labour is straightforward, with most cost from the part itself.
Code Information
| Code Type: | OBD-II Chassis (C) Trouble Code |
| System: | Chassis |
| Code: | C0749 |
C0749 Symptoms
Check Engine Light
Illuminated dashboard warning
Engine Stalling
Engine stops unexpectedly or misfires
Performance Issues
Reduced power or acceleration
Starting Problems
Difficulty starting the engine
C0749 Code Structure
Understanding what each digit means in the C0749 chassis trouble code:
| C | 0 | 7 | 4 | 9 |
|---|---|---|---|---|
| Chassis Code | Intake Valve Control Solenoid Circuit Low | Fuel Rail Pressure Sensor Circuit Malfunction | Injection Pump Fuel Metering Control 'B' High | Reverse Input Circuit |
How to Fix C0749
Diagnostic Steps:
Poor running symptoms align with MAP sensor malfunction. In some cases, a faulty MAP sensor will not trigger a code. The issue may represent separate wiring concerns requiring individual diagnosis.
Repair Solution:
Power steering pressure switch monitors system operation. If pressure changes are not detected after calibrated speed transitions, this DTC sets. Verify PSP switch operation and check for circuit opens or shorts.
Technical Notes:
C0749 DTCs can be triggered by upstream issues. For example, a dirty MAF sensor may cause incorrect fuel-trim adjustments, leading oxygen sensors to report mixture problems. Address root causes first.
C0749 Description
C0749 engine trouble code is related to Reverse Input Circuit.
Main Cause
The primary reason for C0749 OBD-II Engine Trouble Code is: Fuel Rail Pressure Sensor Circuit Malfunction.