Feb 022017

1992 Chevy S10Would a broken map sensor connector cause an odb1 engine code 33 and 34? Right now I have the connection zip tied, but it just will not run right. It is a 1992 Chevrolet S10 2.8 v6.


Yes. If the engine sensor is unable to transmit the frequency to the ECM it will illuminate the check engine light and possibly store code 33 and code 34. The ECM monitors the frequency and thus determines airflow into the engine. Typical idle MAF is 5 to 7 grams per second.

Chevy Engine Code

Feb 022017

2005 Chevy SilveradoI have a 2005 Chevy 2500HD 4X4 that the rear differential is going bad in. It has a 6.0 gas engine with the stock auto transmission and transfer case. I have found a 2006 Chevy 2500HD with the Duramax engine and Allison auto trans and stock transfer case. My question is will the rear end from the 2006 pickup fit my 2005?



If you are buying this replacement differential from a junkyard you may want to inspect it since it is used.

Differential Inspection

  • Check the pinion gear shaft for unusual wear.
  • Check the pinion and the side gear teeth for wear, cracks, scoring and spalling.
  • Look at the thrust washers for wear.
  • Check the fit of the side gears in the differential case and on the axle shafts.
  • Check the differential case for cracks and scoring and replace all of the worn parts as necessary.


Bearings Inspection

Carefully and thoroughly inspect all drive unit parts before assembly. Thorough inspection of the drive parts for wear or stress with subsequent replacement of worn parts eliminates costly drive component repair after assembly.

Important The differential bearings and the bearing cups are matched sets. Replace both the bearing and the cup when either part requires replacement.

  • Lubricate the bearings with axle lubricant. Inspect the bearings for smooth rotation.
  • Look at the bearing rollers for wear.
  • Inspect the bearing cups for wear, cracks, brinelling, and scoring.
Jan 312017

1998 Chevy BlazerI need a transmission solenoid estimate. How much with parts and labor should changing 2 solenoids cost in transmission? Also, if you change 2, how likely is it that others might fail?


Shift solenoids are around $20 each on amazon with the torque converter clutch solenoid around $30. They also offer a 5 Solenoid piece kit under $100. Just depends what direction you want to go. And lastly you are going to need some transmission fluid and a new filter and gasket. About 6 quarts of transmission fluid at around $3. A Transmission filter and gasket kit around $30.

Now we know a shop is going to charge a mark up on the parts and may also want a diagnostic fee and some extra shop supply fees.

Transmission Solenoid Estimate

  • Total Parts + 50% markup = $225
  • Total Labor @$100 per hour(shop rate) = $225
  • Diagnostic fee = $75
  • Shop supplies(rags, cleaners, etc) = $25
  • Tax @7% = $38.50

Total Cost Estimate for 2 solenoids = $588.50 (low end estimate, dealership may charge more)

Total Cost Estimate for 5 solenoids = $765.05



50/50 chance of failure with other solenoids.

Labor time would be about 2 hours for replacing one solenoid. Add an additional 15 minutes for each additional transmission solenoid.

Converter Clutch Solenoid Assembly, Replace (b)

Labor Times
Comments Factory Regular Severe
1.4 1.9 2.2
Comments Factory Regular Severe
w/skid plate add 0.0 0.3 0.3
Jan 312017

1998 Chevy CavalierWhere would you find the torque converter clutch with pulse width modulated?


You would find this installed in the transmission valve body.

torque converter clutch

Torque Converter Clutch (TCC) Solenoid and Switches Replacement

Removal Procedure

  • Remove the valve body cover.
  • Remove the transmission mount bracket.
  • Disconnect the solenoid wire harness from the case electrical connector.
  • Disconnect the wire leads from the pressure switch.
  • Remove the torque converter clutch solenoid bolt from the control valve body.
  • Remove the 3rd clutch pressure switch.
  • Then Remove the 2nd clutch pressure switch.

Installation Procedure

Caution! Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

  • Install the 2nd clutch pressure switch, if applicable.

Tighten to 12 N·m (124 lb in).

  • Install 3rd clutch pressure switch.

Tighten to 12 N·m (124 lb in).

  • Install the torque converter clutch solenoid bolt to the control valve body.
  • Install the O-ring.

Tighten to 12 N·m (124 lb in).

  • Connect the wire leads to the pressure switch.
  • Connect the solenoid wire harness to the case electrical connector.
  • Install the transmission mount bracket.
  • Install the valve body cover with a new gasket.
  • Inspect the oil level.
Jan 302017

1999 Chevy CavalierMy car wont start. I changed the starter. I change the battery. Also change the ignition. The only power that comes on is the dome light and the hazard. When I turn the ignition to “ON” nothing happens.


Wont Start

You can check to battery positive at the “S” terminal on the starter while someone holds the ignition key in the “START” position. If you see battery positive, check the ground. If both are there, replace the starter. It is possible to get a BAD, new starter. If you do not see battery positive at the “S” terminal on the starter you will need to trace the wiring to see why not.

Could be as simple as a blown fuse. Start by checking the main 50 amp fuse and also check the battery voltage at terminal “B” on the starter to make sure your fusible link is good.

Next you will check the neutral switch or clutch pedal switch, depending on if it is an automatic or standard shift. If those check out, the wiring and ignition switch are the only things that are left.

1999 Chevy Cavalier Starting System Wiring Diagram



Jan 262017

 Chevy SilveradoDifficult to start, I have to crank the engine 3 to 4 times.
Fuel pressure ok, new fuel filter installed.
Is there like a throttle solenoid or something causing the problem? thanks


Possible Causes:

  • A leaky fuel pressure regulator
  • A small vacuum leak
  • Intake leak
  • Sticking IAC valve – most common

We are assuming the check engine light is not on.

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.