GMC Recent Questions, Troubleshooting Help & Support

The smart flasher (GMSF) is an automotive flasher designed to accept turn, hazard, and brake inputs. The GMSF will provide corresponding outputs to the exterior lamps and instrument panel turn signal indicator lamps. This lighting system has dedicated lamps for the turn/hazard functions and dedicated lamps for the brake function. The system incorporates the use of flash rates for diagnostics. The flash rate is a calculation of the number of flashes that occur within a 60 second period. This system uses a percentage of on-time to off-time called duty cycle. For the bulb outage condition, the indicator of the vehicle side on which the outage occurs shall assume bulb outage flash rate mode. The opposite side indicator will assume the normal flash rate mode for an input from the non bulb outage side of the vehicle. Hazard warning lamp outage will maintain a normal flash rate as long as 2 or more exterior signaling lamps are functional. During all modes of operation, the IPC will receive the same flash rates and duty cycles that the exterior lamps receive. The IPC will then control the indicators in the cluster. The vehicle operator will be provided with an audible and visual indication of the flasher operation. Below is a table with flash rates and duty cycles: Operating Condition Flash Rate Duty Cycle Normal 75 to 105 flashes per minute 45% to 55% Turn Signal Lamp Outage 2 or 3 times faster than normal flash rate 35% to 55% The IGN E fuse in the engine wiring harness junction block supplies Ignition positive voltage to the turn signal switch assembly. With the ignition switch in the RUN or START position, ignition positive voltage is connected through the turn signal and hazard switch assembly to the GMSF which is powered by the FLASHER fuse also in the engine wiring harness junction block and is grounded at G201. When the turn signal switch is placed in either the left or right position, the circuit is complete from the GMSF to the turn signal lamps and to ground. The GMSF then sends an on-off voltage signal to either the left or right turn signals and their instrument panel cluster (IPC) indicator. When the hazard switch is pressed, all turn signal lamps will flash including both IPC turn indicators. The front turn signals are grounded at G103 and G107. The rear turn signals are grounded at G401 and G402. The IPC illuminates the TURN SIGNAL ON indicator in the driver information center when the IPC determines that the turn signal is active for more than 1.2 km (0.75 mile). The IPC also sends a class 2 message to the radio in order to activate the audible warning. On vehicles equipped with the outside rear view mirror turn signal lamps, the turn signal voltage is also sent to the respective front door module. The door modules then distribute power and ground to the activated lamp. For trailer wiring, separate turn signal circuits are connected through the GMSF to the trailer wiring harness. Just left side front and back are not working? It could need a new turn signal / hazard flasher module.

Various ideas https://www.google.com/search?q=1998+GMC+Jimmy.+factory+amplifier+location ..

https://images.app.goo.gl/sb5LmtVEwsMceubWA

The low oil pressure will not affect the engine rpm. You need to find the low engine idle problem and correct it first. Could be a simple throttle body cleaning. This would clean out the idle control valve which could be the problem. Most service centers will be able to do that.

Sounds like it's worn out, best take into the shop for repair, should only cost $20 with parts.

1 - PPL
2 - RED/WHT
3 - LT BLU
4 - DK GRN/WHT
5 - DK GRN
6 - LT BLU/WHT

Check here..... https://www.2carpros.com/questions/gmc-sonoma-1991-gmc-sonoma-firing-order Best to you.

Idle air solenoid and/or intake vacuum leak.

Service Manuals https://www.google.com/search?q=1994+GMC+Sonoma+4.3+service+manual How to Change A Heater Core on a 1994 GMC Jimmy, (Chevy ...

Question edited for clarity and toss in some CAPS. Question moved to model category. Help in the link. Basically something in the linkage was come apart. The noise is the electronic solenoid. It is the same for all models, you just have to get in there. https://www.google.com/search?q=2008+GMC+Envoy+hatch+won%27t+lock ..

You have AWD? full time all-wheel drive. Transfer Case Description and Operation The Borg Warner (BW) model 4481, RPO NR3 transfer case is a one-speed, full time, all wheel drive (AWD), transfer case. The transfer case provides power to both axles, through an external planetary type differential, which has two different sets of pinion gears. The planetary differential provides a 40/60 torque split, front/rear, full time. This means both axles are constantly being driven for maximum traction in all conditions. The transfer case external type planetary differential functions the same as a typical rear axle differential. The transfer case differential pinion gears function as the spider gears, and the sun gears function as the side gears. The following actions occur because of the planetary differential: • If the vehicle is on a hoist, the front propeller shaft can be rotated by hand. • The vehicle cannot be driven if one propeller shaft is removed. • Operating the vehicle on the hoist can damage the differential pinion gears, by over-spinning. • Operating the vehicle with one propeller shaft removed causes over-spinning of the differential pinion gears. The BW 4481 design of the planetary differential allows the use with the Vehicle Stability Enhancement System (VSES) vehicles. The VSES takes use of the planetary differential, by applying braking to a tire that has less traction and dividing the engine torque to the other axle. The BW 4481 case halves are high-pressure, die-cast magnesium. Ball bearings support the input shaft, the front output shaft, and the rear output shaft. The transfer case requires DEXRON®III ATF GM P/N 12378470 (Canadian P/N 10952622), which is red in color. This system does not have an encoder motor.

Help in the link https://www.google.com/search?q=1995+GMC+Sonoma+SLE%2C+extended+cab%2C+2+wheel+drive.+Replacing+the+5+speed+manual+transmission ..

I thought I answered this? Want to bypass your vehicle security system? The short answer is you can't! All modern cars have alarms and immobilizers. There is a transponder in the key and a receiver around the ignition lock. If both are present, the ECM (engine control module) or BCM (Body Control Module) releases power to the ignition circuit or the starter. When you turn the key, the starter spins the engine and you get a spark. If any one of those three items are not in the chain, you get the engine to turn, but no spark. There is no way to beat the system. You have to fix what is wrong, not find a way around it. The immobilizer is in place to stop exactly what you are trying to do. .. Posted by ADMIN... on Mar 26, 2016

Question edited for a lot more clarity. Question moved to model category. This says it doesn't have one. https://www.justanswer.com/gm/4n355-crank-position-sensor-located-95-gmc-safari-4-3.html https://www.google.com/search?q=1994+GMC+Safari.+Crankshaft+Position+Sensor+location ..

What size engine ? 4.3 L vortex P0300 random misfire code is usually associated with vacuum leaks , but could also be low fuel pressure , plugged fuel filter , fuel pump problem , clogged injectors etc... doing fuel pressure an flow testing would confirm or eliminate that as a problem . Fuel injector balance testing would confirm or eliminate clogged injectors .

https://www.scosche.com/media/guides/ct1031.pdf

PART COLOR LOCATION 12 VOLT CONSTANT RED (+) @ IGNITION SWITCH HARNESS STARTER YELLOW (+) @ IGNITION SWITCH HARNESS STARTER 2 N/A IGNITION 1 PINK (+) @ IGNITION SWITCH HARNESS IGNITION 2 WHITE (+), See NOTE #6 @ IGNITION SWITCH HARNESS IGNITION 3 N/A ACCESSORY/HEATER BLOWER 1 ORANGE (+) @ IGNITION SWITCH HARNESS ACCESSORY/HEATER BLOWER 2 N/A KEYSENSE LIGHT GREEN (-) @ IGNITION SWITCH HARNESS PARKING LIGHTS ( - ) WHITE (-) @ BCM, LIGHT BLUE plug, Pin A5, See NOTE #4 PARKING LIGHTS ( + ) BROWN (+) @ BCM, LIGHT BLUE Plug, Pin B6, See NOTE #4 POWER LOCK LIGHT BLUE (TYPE A) @ BCM, BROWN plug, Pin A4, See NOTE #4 POWER UNLOCK WHITE (TYPE A) @ BCM, BROWN Plug, Pin A3, See NOTE #4 DOOR TRIGGER See NOTE #2 @ BCM, See NOTE #4 DOMELIGHT SUPERVISION TAN (-) @ BCM, PURPLE Plug, Pin B4, See NOTE #4 TRUNK RELEASE N/A SLIDING POWER DOOR N/A HORN BLACK (-) @ STEERING COLUMN HARNESS TACH WHITE (AC) @ ECM, See NOTE *2 WAIT TO START LIGHT DARK BLUE (-), See NOTE #5 @ INSTRUMENT CLUSTER BRAKE WHITE (+) @ SWITCH ABOVE BRAKE PEDAL FACTORY ALARM DISARM LIGHT GREEN (-) @ BCM, PURPLE plug, Pin B3, See NOTE #4 ANTI-THEFT YELLOW (+), ORANGE/BLACK (-) and RED/WHITE (Not used) GM's PASSLOCK 2 System, these wires exit the Ignition Switch Tumbler together and are in the Main Ignition Switch Harness in the Column. EXTRA INFORMATION NOTE #1: This vehicle is equipped with the PASSLOCK 2 ANTI-THEFT SYSTEM and will require a 791 Bypass Module for Remote Starting, to order go to the SECURITY BYPASS MODULE Page on this website. NOTE #2: This vehicle has 2 door trigger wires, the DRIVERS DOOR is a TAN (-) PURPLE plug, B4 and ALL OTHER doors BLUE/WHITE (-) LIGHT BLUE plug, Pin B11 at the BCM use both Door Trigger wires and DIODE ISOLATE when connecting to an ALARM SYSTEM, to connect, See DIAGRAM. NOTE #3; The ECM (Engine Control Module) is located near the battery, down low, between the fender and the fan, under a BLACK plastic cover. On the 4.3L engine it is in a 20 pin connector labled RED. On the 4.8L, 5.3L and 6.0L engines it is located at Pin 10 in the RED connector NOTE #4: The BCM (Body Control Module) is located behind the drivers side of dash, with the plugs facing the rear of the vehicle. NOTE #5: when hooking up a remote starter, if you cannot get the (+) or (-) Wait to Start wire on the Remote Starter to work properly, you will then need to disconnect this wire and Program the Remote Starter for the 5, 10, 15 or 20 Second Wait to Start Timmer in the Installation manual. NOTE #6: IMPORTANT !!!!! this wire MUST BE CONNECTED as IGNITION #2 for REMOTE STARTING!!!!!!