P0045 Turbo/Supercharger Boost Control A Circuit Open
OBD-II Trouble Code Technical Description
ASE Certified Master Technician
Turbocharger/Supercharger Boost Control "A" Circuit Open
What does that mean?
This diagnostic trouble code (DTC) is a generic powertrain code, which means that it applies to OBD-II equipped vehicles that have a supercharger or turbocharger (Chevrolet / GMC / Duramax, Isuzu, Ford, Toyota, Nissan, VW, Hino, etc.). Although generic, the specific repair steps may vary depending on make/model.
Turbochargers and superchargers are air pumps that force air into the engine to increase power. Superchargers are driven off the engine crankshaft by a belt, whereas turbochargers are driven by the engine's exhaust.
Many modern turbocharged vehicles use what's referred to as a variable geometry turbocharger (VGT).This type of turbo has adjustable vanes located around the outside of the turbine that can be opened and closed to vary the amount of boost pressure. This allows the turbo to be controlled independent of engine speed. Generally, the vanes are open when the engine is under light load and open as load increases. Vane position is controlled by the powertrain control module (PCM), typically using an electronic control solenoid or motor. Turbo vane position is determined using a dedicated position sensor.
On vehicles that use a traditional, fixed displacement turbo charger or supercharger, boost is controlled via a wastegate or bypass valve. This valve opens to relieve boost pressure. The PCM monitors this system using a boost pressure sensor.
In reference to this trouble code, the "A" indicates the problem in with a portion of the system circuit, instead of a particular symptom or component.
Code P0045 is set when the PCM detects an open in the boost control solenoid circuit, no matter if the engine uses a VGT turbo or traditional turbocharger/supercharger.
One style of turbocharger boost control solenoid valve:
Related turbo / supercharger engine trouble codes:
- P0046 Turbocharger/Supercharger Boost Control "A" Circuit Range/Performance
- P0047 Turbocharger/Supercharger Boost Control "A" Circuit Low
- P0048 Turbocharger/Supercharger Boost Control "A" Circuit High
- P0049 Turbocharger/Supercharger Turbine Overspeed
- P004A Turbocharger/Supercharger Boost Control "A" Circuit Intermittent/Erratic
Code Severity & Symptoms
The severity of these codes is moderate to severe. In some cases, problems with the turbocharger/supercharger can lead to severe engine damage. It's a good idea to address this code as soon as possible.
Symptoms of a P0045 code may include:
- Insufficient boost resulting in lack of engine performance
- Overboost resulting in detonation and possible engine damage
- Illuminated check engine light
Potential causes for this code to set are:
- Faulty boost pressure/ turbocharger position sensor
- Failed turbocharger/super charger
- Defective control solenoid
- Wiring problems
- Faulty PCM
- Vacuum leaks if the valve is vacuum controlled
Diagnostic and Repair Procedures
Begin by visually inspecting the turbo and turbo control system. Look for loose connections, damaged wiring, vacuum leaks etc. Next, check for technical service bulletins (TSBs) regarding the issue. If nothing is found, you will need to move forward to step by step diagnosis of the system.
The following is a generalized procedure, as testing for this code varies between vehicles. To accurately test the system, you'll want referred to the manufacturer's diagnostic flow chart.
Check system function by commanding the control solenoid to change position using a bidirectional scan tool. Raise the engine RPMS to about 1,200 RPMs and toggle the solenoid between on and off. While doing this, engine RPMs should change and the sensor position PID on the scan tool should change as well. If the RPMs fluctuates but the position/pressure PID does not change, suspect a problem with the sensor or its circuit. If RPMS do not change at all, suspect a problem with the control solenoid, turbo/supercharger or wiring.
- To check the circuit: test for power and ground at the solenoid. Note: the solenoid should be commanded on with a scan tool while making these checks. If either power or ground are lacking, you'll need to trace the factory wiring diagram to determine why.
- Check the turbocharger/supercharger: remove the intake to check the turbo/supercharger for damage or debris. If damage is found, replace the unit.
- Test the position/pressure sensor and circuit: in most cases, the position sensor should have three wires going to it: power, ground and signal. Test that all three are present.
- Test the control solenoid: in some cases, you may be able to test the solenoid by checking its' internal resistance with an ohmmeter. Consult the factory repair information for details. You may also be able to jump the solenoid to power and ground to see if it is operational.
Related P0045 DTC Discussions
- Chevrolet captiva 2.0D 2007 whit fault code p0047 and p0045
Hey. My Name is Jarle and comes from Norway. I bought a Chevrolet Captiva 2.0D with engine code C20DM. And after 3-4 months I had problems with it. The problem is that the car cuts out the turbo. tried to switch the vacuum valve to the turbo. but this was not working. anyone have more suggestions? ...
- Jaguar S Type 2005 2.7 Tdi twin turbo P0045 P004B
Has anyone had these two codes appear on the OBD2 following a limp mode restricted performance notification? P0045 - Turbocharger boost control solenoid circuit A open.And P004B Turbocharger boost control B circuit range performance? I suspect the solenoid wiring but have no way of finding out. I w...
- Code help: 2004 F150 code P0045
I got this code from autozone. The guy said it was a rare code and had to do with oxygen control sensor. But it seemed that it may be a problem with the circuit but he was not sure. Any idea how to fix this?? Thanks in advance....
- 2004 Nissan Altima Code P0045
Can anyone tell me what this code means? Its not on any of the lists I've seen. Thanks!!!...
Need more help with a p0045 code?
If you still need help regarding the P0045 trouble code, please post your question in our FREE car repair forums.
NOTE: This information is presented for information purposes only. It is not intended as repair advice and we are not responsible for any actions you take on any vehicle. All information on this site is copyright protected. If you want to share this article or information with others, please link to this page, don't copy and paste it elsewhere.