GMC Denali - Recent Questions, Troubleshooting & Support

You have a bad ground wire. It will be eithr the ground on the trailer or the car harness. To confirm this diagnosis, take a set of jumper cables and hook one end to the trailer tongue and the other end to the car hitch. If your lights work, then you know it is a ground. The other possibilty is that you have a blown fuse.

There is no factory kill switch.
You need to explain your complaint ... Guessing at the reason will not help here.
If the engine spins around with the key but will not start then you have a crank no start. If you kick the bottom of the gas tank whild someone is turning the key to the start position and it starts then you need a fuel pump. Very common and about a $500 job on the low end.

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Doesn't sound like the all wheel drive is working.

I know this website www.reliable-store.com that i get manuals from, and they have all models online that solve all simple/technical problems like professionals I also brought for my 1989 BMW, such old model, they had it and it was very good manual. Go ahead, I bet.

Your OBD port fuse may have blown. It is often the same fuse as the lighter.

Try to get the OBD code to tell you the problem. probably one of the ride height sensors located at each wheel.

no. purchas an adapter that will allow you to convert one of your XM channels to an AUX input.

Spark Plug Spark Plug Wire Fuel Injector Coil

Purchase a CD player cleaning disc. Try Best Buy

P0134 O2 sensor drivers side before catalytic converters. PO141 O2sensor drivers side after converter P1133 insufficient switching of O2 sensors. Will probably go away once sensors are replaced.

Check the abs sensor on that wheel and it's wiring. It sits very close to brake disk and could be loose or fouls by dirt and corrosion. Easy to replace.

Are you talking about the HVAC SYSTEM? If so, there are 3to 4 in front , same with rear if you have rear air option. They have different part numbers too.

Taking the vehicle to a qualified repair shop an having a full scan of all the control module's on the vehicle should be the first step in the diagnostic procedure , All the instrument cluster gauge function's start in the PCM - engine computer . Sent to the instrument cluster over the GMLAN serial data network . Without testing we'd only be guessing . Probably has a U code stored in one of the module's pointing to a cause . Could be just a loose connection . Checking wiring harness connection's . Circuit Description The communication among control modules is performed through the high speed GMLAN serial data bus, the low speed GMLAN serial data bus, and with RPO HP2 the high speed hybrid GMLAN serial data bus. The modules that need real time communication are attached to the high speed GMLAN busses. There are several modules that act as the gateway module or translator for communication between the various serial data busses. With RPO HP2 the serial data gateway module (SDGM) is the gateway and on all others the body control module (BCM). All high speed modules are activated by a communication enable or wakeup circuit from another module as determined by the power mode master (PMM). Refer to Data Communication Schematics to determine the circuit and module that activates specific high speed modules. Signal supervision is the process of determining whether an expected signal is being received or not. Some messages are sent on a periodic basis and are interpreted as a heartbeat of a device. If such a signal is lost, the signal supervision part of the software will set a no communication DTC (U. code) against the missing device. This code is mapped on the Tech 2 screen as a code against the physical device. A lost communication DTC typically is set in modules other than the module with a communication failure. Speedometer The IPC displays the vehicle speed as determined by the ECM. The IPC calculates the mileage based on the serial data vehicle speed information from the ECM. The speedometer defaults to 0 km/h (0 mph) if the IPC detects a loss of serial data communications with the ECM. Tachometer The IPC displays the engine speed as determined by the ECM. The IPC receives a serial data message from the ECM indicating the engine speed. The tachometer will default to 0 RPM if: • The ECM detects a malfunction in the engine speed sensor circuit. • The IPC detects a loss of serial data communications with the ECM. CAN Communication Problem How to Diagnose Controller Area Network CAN http://www.bbbind.com/free_tsb.html free wiring diagrams here . Enter vehicle info. year , make , model an engine size . Under system click on body & accessories , then under subsystem click on communication systems . Click the search button ,then the blue link's . Communication network diagrams .

How do you know it's the circuit board ? What rear door ? Sound's to me like your best bet would be to take your vehicle to a qualified repair shop . Are your guessing or did you test ? Scan tool to check for diagnostic trouble code's ?

1. Question, why was the throttle cleaned? but check any links that are attach to throttle, and clean any items around it, and if is spring loaded, clean spring with electrical spray

Your battery will not take a charge - replace it.

Hi the last digit is 0 this means its detected a fault but it does not know why the misfire is if it had 1 at end it would be sparkplug 1. and so on. 0 could mean there is a problem with the timing or there is something wrong with the coil pack , coil pack it could be a fault at the plugs or the wiring. if you remove the spark plugs and the one or 2 that don't look right, investigate them, make sure there is no problems with the case of the coil pack. color of the connections and the case cover no cracks or splits. it can also be blocked jets this can limit the fuel into the engine and cause the same fault.

Have the vehicle checked for DTC'S - diagnostic trouble codes ! Do you know what electronic throttle control is ? The gas pedal assembly has electrical connector an sensors inside ,hooked to the PCM / ECM - engine computer . The engine computer uses these position sensors inputs to control the DC motor on the throttle body to open the throttle plate to control the speed . Plus there are position sensors inside the throttle body to input PCM/ECM to see if it's calculations are corect . Your best bet maybe to take it to a qualified repair shop . Drive by Wire Function and diagnostics by Wells 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 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 motor and the throttle will return to the spring loaded default position. • 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.

How may buttons for the 4X4 two , three , or four ? Do the lights flash ? Any messages - service four wheel drive system ? Which transfer case does it have ? Transfer Case - NVG 246-NP8 (Two Speed Automatic) The transfer case shift control module uses the VIN information for calculations that are required for the different calibrations used based on axle ratio, transmission, tire size, and engine. The system does not know which calibration to use without this information. Transfer Case Encoder Motor The transfer case encoder motor consists of a permanent magnet (PM) DC motor and gear reduction assembly. It is located on the left hand side (drivers side) of the transfer case. When activated it turns the sector shaft of the transfer case (clockwise or counter clockwise) to shift the transfer case. The encoder motor is controlled with a pulse width modulated (PWM) circuit within the transfer case shift control module. This circuit consists of a driver on both the Motor Feed A and Motor Feed B circuits. The encoder motor is bi-directional to allow the motor to shift the transfer case from 2HI or 4HI to NEUTRAL and 4LO positions. Transfer Case Encoder The encoder is mounted to the transfer case encoder motor assembly and is replaced as an assembly. The encoder converts the sector shaft position (representing a mode or range) into electrical signals inputs to the transfer case shift control module. The module can detect what position the transfer case is in by monitoring the 4 encoder channels (P, A, B, and C). These inputs translates into AUTO 4WD, 2H, 4H, NEUTRAL, and 4L or in transition between gears. Transfer Case Motor Lock The transfer case motor lock is used to provide a 2H, 4H, and 4L lock-up feature. When the lock circuit is energized, the transfer case encoder motor is allowed to turn. When the transfer case is placed 2H, 4H, or 4L the motor lock circuit has no power provided to it and the lock is applied. This assures that the transfer case remains in the current gear position. When AUTO 4WD is selected the motor lock remains applied until an adaptive mode (torque is applied to the front propshaft) is required. During an adaptive mode the motor lock circuit is energized and the motor lock is released, enabling the encoder motor to turn and apply torque to the front propshaft. SERVICE indicator (4WD/AWD) Lamp The SERVICE indicator (4WD/AWD) lamp is an integral part of the cluster and cannot be serviced separately. This lamp is used to inform the driver of the vehicle of malfunctions within the automatic transfer case (ATC) system. The SERVICE indicator (4WD/AWD) lamp is controlled by the transfer case shift control module via a Class 2 message or by a Sevice Indicator Control Circuit. The first thing to do before assuming it's a loose wire would be to have it checked for codes , auto zone , advance etc... can not check this codes . DTC B0768 Service Indicator Circuit High DTC B2725 ATC Mode Switch Circuit Malfunction DTC C0300 Rear Speed Sensor Malfunction DTC C0305 Front Speed Sensor Malfunction DTC C0308 Motor A/B Circuit Low DTC C0309 Motor A/B Circuit High DTC C0310 Motor A/B Circuit Open DTC C0315 Motor Ground Circuit Open DTC C0323 T-Case Lock Circuit Low DTC C0324 T-Case Lock Circuit High DTC C0327 Encoder Circuit Malfunction DTC C0357 Park Switch Circuit High DTC C0362 4LO Discrete Output Circuit High DTC C0367 Front Axle Control Circuit High DTC C0374 General System Malfunction DTC C0376 Front/Rear Shaft Speed Mismatch DTC C0387 Unable to Perform Shift DTC C0550 ECU Malfunction DTC C0611 VIN Information Error If you know nothing about this , your best bet would be to take it to a qualified repair shop .