Jan 232017

2003 Chevy ImpalaThe ignition tumbler is damaged and the key will no longer work . How do I remove the lock tumbler with out being able to turn it to “acc” like normal.


Replacing Ignition Lock Cylinder

Use the following procedure if the ignition switch lock cylinder is seized or won’t rotate:

Ignition Tumbler replacement diagram


  1. Protect the immediate work area with suitable material such as clean shop towels or a clean fender cover.
  2. Locate the surface for the release button (2) for the ignition switch lock cylinder on the plastic ignition switch housing. Center punch a location (1) on the rib approximately 3/8 inch reward, toward the key entry end, from the cylinder release button.
  3. Carefully drill a pilot hole through the plastic housing with a 1/8-inch drill bit.
  4. Using a 9/32-inch drill bit, carefully drill a larger hole at the pilot location, and slightly into the surface of the ignition switch lock cylinder, to break the release button retaining spring.
  5. Remove portions of the broken spring from the hole using a small suitable tool.
  6. Grasp the ignition switch lock cylinder and remove the cylinder from the switch housing.
  7. Remove any plastic flash from the drilling operation, and using compressed air blow out the ignition switch assembly.
  8. Follow service manual procedures when cylinder coding is required.

Perform the body control module (BCM) theft deterrent relearn procedure whenever you replace the ignition switch lock cylinder.

Programming Theft Deterrent System Components


  • The body control module (BCM) must be programmed with the proper RPO configurations before performing learn procedures. Refer to Body Control Module (BCM) Programming/RPO Configuration in Body Control System.
  • If replacing the BCM with a GM Service Parts Operations (SPO) replacement part, the module will learn Passlock™ sensor data code immediately. The existing PCM however, must learn the new fuel continue password when the BCM is replaced.
  • If replacing a PCM with a GM Service Parts Operations (SPO) replacement part, after programming, these modules will learn the incoming fuel continue password immediately upon receipt of a password message. Once a password message is received, and a password is learned, a learn procedure must be performed to change this password again. A PCM which has been previously installed in another vehicle will have learned the other vehicle’s fuel continue password and will require a learn procedure after programming to learn the current vehicle’s password.

Use this procedure after replacing any of the following:

  • Passlock™ Sensor
  • BCM
  • PCM

Learn Procedures

There are two available methods to perform the programming procedure:

  • A 10 minutes procedure which requires a Tech 2 and a techline terminal.
  • A 30 minutes procedure which does not require the use of any tools.10 Minute Learn Procedure

Tools Required

  • Tech 2
  • Techline terminal with current SPS (Service Programming System) software
  • Connect the Tech 2 to the vehicle.
  • Select “Request Information” under “Service Programming”.
  • Disconnect the Tech 2 from the vehicle and connect it to a techline terminal.
  • On the techline terminal, select “Theft Module Re-Learn” under “Service Programming”.
  • Disconnect the Tech 2 from the techline terminal and connect it to the vehicle.
  • Turn ON the ignition, with the engine OFF.
  • Select “VTD Re-Learn” under “Service Programming”.
  • Attempt to start the engine, then release the key to ON (vehicle will not start).
  • Observe the SECURITY telltale, after approximately 10 minutes the telltale will turn OFF (the vehicle is now ready to relearn the Passlock™ Sensor Data Code and/or password on the next ignition switch transition from OFF to CRANK).
  • Turn OFF the ignition, and wait 5 seconds.
  • Start the engine (the vehicle has now learned the password).
  • With the Tech 2 (scan tool), clear any DTCs.30 Minute Learn Procedure

Tools Required

  • Turn ON the ignition, with the engine OFF.
  • Attempt to start the engine, then release the key to ON (vehicle will not start).
  • Observe the SECURITY telltale, after approximately 10 minutes the telltale will turn OFF.
  • Turn OFF the ignition, and wait 5 seconds.
  • Repeat steps 1 through 4 two more times for a total of 3 cycles/30 minutes (the vehicle is now ready to relearn the Passlock™ Sensor Data Code and/or passwords on the next ignition switch transition from OFF to CRANK).


The vehicle learns the Passlock™ Sensor Data Code and/or password on the next ignition switch transition from OFF to CRANK. You must turn the ignition OFF before attempting to start the vehicle.

  • Start the engine (the vehicle has now learned the Passlock™ Sensor Data Code and/or password).
  • With a scan tool, clear any DTCs if needed (history DTCs will self clear after 100 ignition cycles).
Jan 172017

2001 Chevy SilveradoPower Mirrors won’t work, can’t find a fuse for it on the fuse block. Is there a in line fuse some where?


There is not an inline fuse for the mirrors. It would appear, after looking at the wiring diagram, that the mirror fuse and clock fuse are one in the same. It also powers the drivers door power windows and lock switch. So if all that is working most likely the fuse is good.

Mirror Fuse Location

The fuse is located in the Fuse Block. It is a 3 amp fuse. The label should be “MIR/CLOCK”. Look under the fuse block cover for a list of fuses and exact location.

Power Mirrors Wiring Diagram

Jan 142017

2000 Chevy SilveradoHeater blower burnt out for a second time. Is this common?


This can be common for a 17 year old truck for sure. Also the after market blower motor will not be the same quality and won’t last near as long as the original motor.

If the blower motor only works on high speed or certain speeds the motor itself may be just fine. The problem would be with a faulty blower motor resistor.

HVAC Blower Controls Circuit Description

Battery voltage is supplied to the blower motor resistor relay assembly connector at all times. When the ignition switch is OFF or the blower switch is in any position except HI, no voltage is applied to the relay coil via blower high speed and the relay remains de-energized.

With the blower switch in HI, the blower resistors are bypassed and voltage is supplied to the coil side of the permanently grounded relay. This closes the contacts and supplies full battery voltage from the engine wiring harness junction block to the blower motor which will operate at the highest speed.

When the blower switch is in LO to any MEDIUM speed, voltage is reduced through the appropriate resistors which will limit the blower speed accordingly.

The blower motor resistor relay assembly is located next to blower motor under right side of glove compartment (Pickup) or at the right rear module assembly (Utilities w/auxiliary A/C).

Jan 122017

1993 Chevy Dump TruckMy truck is a standard and it doesn’t want to go into gear clutch seems to work fine and this happened all of a sudden.


With the engine off, see if you are able to shift into different gears. If yes, then your clutch is the problem. If no, your transmission is the damaged internally.

Understanding How The Clutch Works

The purpose of the clutch is to disconnect and connect engine power at the transmission. A vehicle at rest requires a lot of engine torque to get all that weight moving. An internal combustion engine does not develop a high starting torque (unlike steam engines) so it must be allowed to operate without any load until it builds up enough torque to move the vehicle. To a point, torque increases with engine rpm. The clutch allows the engine to build up torque by physically disconnecting the engine from the transmission, relieving the engine of any load or resistance.

The transfer of engine power to the transmission (the load) must be smooth and gradual; if it weren’t, drive line components would wear out or break quickly. This gradual power transfer is made possible by gradually releasing the clutch pedal. The clutch disc and pressure plate are the connecting link between the engine and transmission. When the clutch pedal is released, the disc and plate contact each other (the clutch is engaged) physically joining the engine and transmission. When the pedal is pushed in, the disc and plate separate (the clutch is disengaged) disconnecting the engine from the transmission.

Most clutch assemblies consists of the flywheel, the clutch disc, the clutch pressure plate, the throw out bearing and fork, the actuating linkage and the pedal. The flywheel and clutch pressure plate (driving members) are connected to the engine crankshaft and rotate with it. The clutch disc is located between the flywheel and pressure plate, and is splined to the transmission shaft. A driving member is one that is attached to the engine and transfers engine power to a driven member (clutch disc) on the transmission shaft. A driving member (pressure plate) rotates (drives) a driven member (clutch disc) on contact and, in so doing, turns the transmission shaft.

Clutch Assembly

There is a circular diaphragm spring within the pressure plate cover (transmission side). In a relaxed state (when the clutch pedal is fully released) this spring is convex; that is, it is dished outward toward the transmission. Pushing in the clutch pedal actuates the attached linkage. Connected to the other end of this is the throw out fork, which hold the throw out bearing. When the clutch pedal is depressed, the clutch linkage pushes the fork and bearing forward to contact the diaphragm spring of the pressure plate. The outer edges of the spring are secured to the pressure plate and are pivoted on rings so that when the center of the spring is compressed by the throw out bearing, the outer edges bow outward and, by so doing, pull the pressure plate in the same direction–away from the clutch disc. This action separates the disc from the plate, disengaging the clutch and allowing the transmission to be shifted into another gear. A coil type clutch return spring attached to the clutch pedal arm permits full release of the pedal. Releasing the pedal pulls the throw out bearing away from the diaphragm spring resulting in a reversal of spring position. As bearing pressure is gradually released from the spring center, the outer edges of the spring bow outward, pushing the pressure plate into closer contact with the clutch disc. As the disc and plate move closer together, friction between the two increases and slippage is reduced until, when full spring pressure is applied (by fully releasing the pedal) the speed of the disc and plate are the same. This stops all slipping, creating a direct connection between the plate and disc which results in the transfer of power from the engine to the transmission. The clutch disc is now rotating with the pressure plate at engine speed and, because it is splined to the transmission shaft, the shaft now turns at the same engine speed.

The clutch is operating properly if:

  1. It will stall the engine when released with the vehicle held stationary.
  2. The shift lever can be moved freely between 1st and reverse gears when the vehicle is stationary and the clutch disengaged.
Jan 102017

Chevy AstroOK, as I was leaving work, I put my vehicle into drive but had my foot on the brakes; suddenly my tires started spinning and made noises as if I were burning out as soon as I put it in drive. It did something similar the day before as I was pulling into my parking spot at home, this time it felt like it was accelerating a little bit as I pressed on the brakes. It did rain a bit that day. Could this be a transmission issue or could it be a brake issue?


Not a transmission issue. Possibly a brake issue if only the front brakes are working. However the tires do not tend to spin at idle with the brake applied. I would look more at your foot. Have you started wearing a bigger shoe or boot as of late? Sometimes when you think you are only applying the brake the side of your shoe is also applying a small amount of pressure on the gas pedal. Happens to the best of us.

Jan 092017

1996 Chevy Silverado 1500Where is the cam sensor located I really would love to see a picture?


It is located inside the distributor assembly.

Camshaft Position Sensor Replacement


System Operation

The enhanced ignition system used on all OBD II engines somewhat resembles the current distributor ignition (DI) system described in the ignition systems. However, the system has been greatly enhanced in order to make it compatible with the new OBD II regulations. The enhanced ignition system provides a spark at precisely the correct time in order to ignite the air and fuel mixture for optimum performance and fuel economy. The system consists of the following components:
•Vehicle control module (VCM)
•Ignition coil driver module
•Ignition coil
Crankshaft position (CKP) sensor

This system does not use the ignition module used on the DI systems in the past. The VCM controller now controls the ignition control (IC) and bypass functions.

How It Works

The crankshaft sensor, located in the front engine cover, is perpendicular to a target wheel attached to the crankshaft. The target wheel is equipped with slots situated 60 degrees apart. As the crankshaft rotates, the target wheel rotates past the crankshaft position sensor. The rising and falling edges created by the slots cause a signal to be sent back to the VCM. This signal occurs three times per crankshaft revolution and is referred to as the 3x signal for V6 applications. The signal occurs four times per crankshaft revolution and is referred to as the 4x signal for V8 applications.

The VCM then utilizes this 3x (V6) or 4x (V8) signal in order to provide the correct spark to the engine by way of the single coil driver module. The single coil driver module is basically an electronic switch that when commanded by the VCM, causes the primary coil voltage to breakdown, energizing the secondary coil and providing a spark via the coil wire to the distributor cap. The distributor consists of the following components:
•Cap and rotor
•Camshaft position (CMP) sensor
•Gear drive and shaft

The camshaft drives the distributor shaft which rotates providing a spark to the correct cylinder by way of the cap and rotor. The camshaft position sensor functions much like the crankshaft sensor previously described but provides only a 1x signal to the VCM. That is, for every 2 rotations of the crankshaft, there is 1 rotation of the camshaft. Note that the CMP sensor will not affect driveability. The sole purpose of the CMP sensor is to provide the VCM with the necessary information for the misfire DTCs.



Jan 062017



The smoke is just an indication of a fluid leak. You can check your fluid levels periodically to determine which fluid level is getting low. This is the fluid that is leaking.

If the check engine light is on it may have a code that will help diagnose the cause of the skipping. The good news is just about any local auto parts store will pull the codes for free. Once you have the code post them and I can give you the right information.

Dec 222016

1999 Chevy S10I replaced the thermostat and radiator cap but no heat. why?


Did it have heat before you replaced these parts?

Did you properly bleed the cooling system after replacing these parts?

Is the coolant level full?

First thing to check would be the coolant level in the radiator and overflow. Next, once the engine is brought up to operating temperature check the heater hoses going to the firewall. If both hoses are hot the problem most likely is with the blend door function. This is inside the HVAC box under the dash. If the temperature blend door actuator or the blend door itself is stuck, no heat will be felt.

Dec 202016

Chevy tahoeRecently the engine service light came up with code P0300 multiple misfires. I used timing light to pin point which cylinder wasn’t firing and came up with #4 and #8. So I checked wire for resistance and plugs seemed to be fine. In addition I replaced both coils and I still have multiple misfires on #4 and #8. my next step would be?


Chevy Code P0300 – Cylinder Misfire Detected Random Cylinders

The P0300 code means that a cylinder(s) is misfiring or is randomly misfiring. Therefore , start by checking for intake leaks, intake gaskets are common caused of multi-cylinder misfiring. If no leak are found the next step is to replace the spark plugs. In conclusion if the problem persist more tests needs to be done to diagnose problem, proceed to “Possible Causes”.

P0300 Possible causes

  • Faulty spark plug (s)
  • Faulty ignition coil (s)
  • Clogged or faulty fuel injector (s)
  • Intake air leak
  • Fuel injectors harness is open or shorted
  • Fuel Injectors circuit poor electrical connection
  • Ignition coils harness is open or shorted
  • Ignition coils circuit poor electrical connection
  • Insufficient cylinders compression
  • Incorrect fuel pressure

There is a factory Technical Service Bulletin on this Vehicle for Code P0300: TSB#03-06-030F

Dec 182016



Adjust Idle

Beginning in 1985, some engines were available with a throttle body fuel injection system. And all engines were fuel injected starting in the 1986 model year. By 1992 a central multi-port fuel injected engine became available as well. All fuel injected engines are controlled by a computer. This computer regulates idle speeds. It also supplies the correct amount of fuel during all engine operating conditions. No periodic adjustments are necessary or possible. Therefore there are no adjustments to be made.

When the idle is high, check for a vacuum leak. If it is low try cleaning the throat of the throttle body and check your air filter. When the idle seems to be stuck, clean or replace the IAC – Idle Air Control valve.

IAC Replacement

1.Disconnect the negative battery cable.
2.Disengage the electrical connector from the idle air control valve.
3.Loosen and remove the threaded IAC control valve and gasket using either a 1 1 ⁄ 4 in. (32mm) wrench, J-33031, or equivalent.
To install:

Before installing a new idle air control valve, measure the distance that the valve extends (from the motor housing to the end of the cone); the distance should be no greater than 1 1 ⁄ 8 in. (28mm). If it is extended too far, damage may occur to the valve when it is installed.

4.Measure the valve pintle extension. To retract the pintle on a NEW valve, use firm thumb pressure and, if necessary, rock the pintle with a slight side-to-side motion. BUT, if reinstalling a used valve on which the pintle is extended further than specification, an IAC tester MUST be used to electrically retract the pintle.
NOTE: Do not attempt to physically retract a pintle on an IAC valve that has been in service, the force may damage the pintle threads. The force required to retract the pintle is only safe on NEW IAC valves.

5.Install the IAC valve and gasket to the throttle body and tighten to 13 ft. lbs (18 Nm).
6.Engage the valve electrical connector.
7.Connect the negative battery cable.
8.Reset the IAC valve pintle: A.There are 2 possible methods to resetting the IAC valve. First, depress the accelerator pedal slightly, then start and run the engine for 5 seconds. Shut the engine OFF for 10 seconds, then restart it and check for proper idle operation. If this does not work, start and run the engine until it reaches normal operating temperature. Drive the vehicle and the IAC valve will reset once vehicle speed is above 35 mph.