Reduced engine power comes across the display and I can't accelerate over 45 mph. after killing the engine and sitting 2-3 minutes it restarts and the display goes back to the odometer and everything operates normally. happened twice during my first trip after roughly 8 miles of traveling at 60-65 mph. the second trip it happened after 45 miles of traveling at 75 mph.

reduced engine power sensor ??? There is no reduced engine power sensor, Now a message on the DIC -driver information center, reduced engine power is a different story . Reduced Engine Power Refer to Powertrain Control Module Description in Engine Controls


Reduced Engine Power Mode
When the PCM detects a condition with the TAC system, the PCM may enter a reduced engine power mode. Reduced engine power may cause one or more of the following conditions:
• Acceleration limiting--The PCM will continue to use the accelerator pedal for throttle control; however, the vehicle acceleration is limited.
• Limited throttle mode--The PCM will continue to use the accelerator pedal for throttle control; however, the maximum throttle opening is limited.
• Throttle default mode--The PCM will turn off the throttle actuator motor and the throttle will return to the spring loaded default position.
• Forced idle mode--The PCM will perform the following actions:
• Limit engine speed to idle by positioning the throttle position, or by controlling the fuel and spark if the throttle is turned off.
• Ignore the accelerator pedal input.
• Engine shutdown mode--The PCM will disable fuel and de-energize the throttle actuator.

You need to hook up a scan tool an check for DTC'S - diagnostic trouble codes .

Sorry , no reset for the fuel pump . Reduced engine power message is for the TAC - throttle actuator control system . Electronic throttle control . Reduced Engine Power: Throttle Actuator Control (TAC) System Description for the 3.6L engine or Throttle Actuator Control (TAC) System Description.TAC System Default Actions/Reduce Power Modes
There are 2 reduce power modes that the engine control module (ECM) can default to if an error is detected in the throttle actuator control (TAC) system. If an accelerator pedal position (APP) sensor 1 or APP sensor 2 circuit fault, throttle position (TP) sensor 2 circuit fault, or if a TP sensor 1 circuit fault is detected with some APP angle, the ECM goes into one of the 2 reduce power modes. In this mode, the engine torque is limited so that the vehicle cannot reach speeds of more than 100 km/h (60 mph). The ECM remains in this reduce power mode during the entire ignition cycle even if the fault is corrected.
If there is a condition with the throttle actuator control circuits, throttle actuator command vs actual position fault, return spring check fault, or a TP sensor 1 circuit fault, the ECM goes into the other reduce engine power mode. In this mode, the engine speed is limited to 2,500 RPM and the 3-6 fuel injectors are randomly turned OFF. At this time the Reduced Power indicator is commanded ON. The ECM remains in the reduce power mode during the entire ignition cycle even if the fault is corrected. Observe, if a TP sensor 1 or throttle actuator control circuit fault is present at the time the vehicle is at idle, with no accelerator pedal angle, the engine may stall.

There is a harness in the engine compartment that has grounded out or shorted. The message 'reduced power' will flash across your driver information display on your gauge cluster. This is somewhat of a common problem for full size Gm trucks (silverado, tahoe, suburban, etc .) and trailblazer/envoy vehicles.

the "Reduced Engine Power", problem causes the PCM to disable "Service Stability Control" and "Traction Control" turning on the warning lights to come on for those systems . The reduced engine power is because of a problem with the electronic throttle control system or as GM calls it TAC system . Reduced Engine Power Mode
When the PCM detects a condition with the TAC system, the PCM may enter a reduced engine power mode. Reduced engine power may cause one or more of the following conditions:
• Acceleration limiting--The PCM will continue to use the accelerator pedal for throttle control, however, the vehicle acceleration is limited.
• Limited throttle mode--The PCM will continue to use the accelerator pedal for throttle control, however, the maximum throttle opening is limited.
• Throttle default mode--The PCM will turn OFF the throttle actuator motor and the throttle will return to the spring loaded default position.
• Forced idle mode--The PCM will perform the following actions:
- Limit engine speed to idle by positioning the TP, or by controlling the fuel and spark if the throttle is turned OFF.
- Ignore the accelerator pedal input.
• Engine shutdown mode--The PCM will disable fuel and de-energize the throttle actuator.
© 2017 General Motors Corporation. All rights reserved.



Drive by Wire training Your best bet , take it to a GM dealer

Engine power reduced , problem with the electronic throttle control ! Watch a couple of video's on youtube , google GM engine power reduced . The gas pedal an the throttle body have position sensor's ,when the PCM/ECM - engine computer see conflicting input's from one of these sensors it send's into a reduced power mode . Your best bet mite be to take it to a qualified repair shop.

With GM vehicles a Reduced Engine Power message has to do with the electronic throttle control .


GM Chevy Truck REDUCED ENGINE POWER Case Study Part 1

Your vehicle has an issue with the accelerator actuators. There is a sensor on the pedal and also on the engine throttle. For some reason, there is a miss communication between the two and will require a diagnostic scan tool to resolve.

This has nothing to do with the heat on the vehicle .
Reduced Power
The reduced power telltale is turned ON by the cluster when it receives a command from the body control module (BCM). The engine control module (ECM) (L81) engine sends a message to the BCM over the CAN serial data link.
The reduced power telltale is illuminated when the ECM is limiting engine torque in a low traction situation. This telltale is used only for the V6 (L81) engine application.
The reduced power telltale is turned ON by the cluster for 2-3 seconds, when the ignition is turned to RUN, for a visual system check.

Taking the vehicle to a qualified repair shop an having it diagnosed would be your best . Unless you have a factory tech 2 scan tool to read BCM DTC'S - diagnostic trouble code's an have factory diagnostic repair info.
Reduced Engine Power Mode
When the ECM detects a condition with the TAC system, the ECM may enter a reduced engine power mode. Reduced engine power may cause one or more of the following conditions:
• Acceleration limiting--The ECM will continue to use the accelerator pedal for throttle control; however, the vehicle acceleration is limited.
• Limited throttle mode--The ECM will continue to use the accelerator pedal for throttle control; however, the maximum throttle opening is limited.
• Throttle default mode--The ECM will turn off the throttle actuator motor and the throttle will return to the spring loaded default position.
• Forced idle mode--The ECM will perform the following actions:
• Limit engine speed to idle by positioning the throttle position, or by controlling the fuel and spark if the throttle is turned off.
• Ignore the accelerator pedal input.
• Engine shutdown mode--The ECM will disable fuel and de-energize the throttle actuator.

Check the vehicle for DTC'S - diagnostic trouble code's should be the first step in diagnosing this problem . But a tune - up not ! Reduced enging power is caused by a problem with the electronic throttle control . If you are not familiar with this ,your best bet would be to take to a qualified repair shop.
REDUCED ENGINE POWER: Refer to Powertrain Control Module Description in Engine Controls - 4.8L, 5.3L, and 6.0L

Throttle Actuator Control (TAC) Overview
The throttle actuator control (TAC) system uses vehicle electronics and components to calculate and control the position of the throttle blade. This eliminates the need for a mechanical cable attachment from the accelerator pedal to the throttle body. This system also performs the cruise control functions as well.
The TAC system components include, but are not limited to the following:
• The accelerator pedal position (APP) sensors
• The throttle body
• The powertrain control module (PCM)
Each of these components interface together to ensure accurate calculations and control of the throttle position (TP)
Accelerator Pedal Position (APP) Sensor
The APP sensor is mounted on the accelerator pedal assembly. The APP is actually 2 individual APP sensors within 1 housing. There are 2 separate signal, low reference, and 5-volt reference circuits. APP sensor 1 voltage increases as the accelerator pedal is depressed. APP sensor 2 voltage decreases as the accelerator pedal is depressed.

One of these sensors could be sending conflicting data to the PCM - engine computer .

Reduced Engine Power Mode
When the PCM detects a problem with the throttle actuator control (TAC) system the PCM enters one of the following Reduced Engine Power Modes:
• Acceleration Limiting--The control module will continue to use the accelerator pedal for throttle control, however the vehicle acceleration is limited.
• Limited Throttle Mode--The control module will continue to use the accelerator pedal for throttle control, however the maximum throttle opening is limited.
• Throttle Default Mode--The control module will turn off the throttle actuator.
• Forced Idle Mode--The control module will perform the following actions:
- Limit engine speed to idle by positioning throttle position, or by controlling fuel and spark if throttle is turned off.
- Ignore accelerator pedal input.
• Engine Shutdown Mode--The control module will disable fuel and de-energize the throttle actuator.

Throttle Body Assembly
The throttle body for the throttle actuator control (TAC) system is similar to a conventional throttle body with several exceptions. One exception being the use of a motor to control the throttle position instead of a mechanical cable. Another exception is the throttle position (TP) sensor. The TP sensor is mounted in the throttle body assembly. The TP sensor is 2 individual TP sensors within the throttle body assembly. Two separate signal, low reference, and 5-volt reference circuits are used to connect the TP sensors and the powertrain control module (PCM). TP sensor 2 signal voltage increases as the throttle opens. TP sensor 1 signal voltage decreases as the throttle opens.

Display reads "Engine Power Reduced" and sometimes won't accelerate beyond idle. Other times it accelerates normally. We have not yet noticed a pattern.