Nov 302018
 

I changed my calibers and now I have a grinding noise in the brakes. I tightened the wheel bearing but it came back.


Most likely the brake dust shield got accidentally bumped and it is rubbing against the brake rotors. A close inspection of all moving parts will be needed. If this only occurs when the brakes are applied, you may need to remove the calipers and inspect there. If the noise was there before you installed the calipers and it went away when you tightened the bearings, there may be an issue with the bearings.

Nov 292018
 

Buick Century

Drivers side blowing cold air

1998 Buick Century Limited: It’s winter and I would like hot air to come out of both the driver side and passenger side middle-level vents. The problem seems to be that temperature is working for the passenger side but not the right side. Here are some clues:

– No amount of fiddling with the HVAC buttons in Auto or Manual mode seemed to fix the problem. Most of my tests were in manual mode because Auto seemed to behave the same. Also DUAL mode was OFF during these tests.
– Changing the temperature changed the temperature of the air on the passenger side but the driver side remained cold and unchanged. When temperature was set lower, both side would push cold air. At max high-temp, still cold air on driver side and then passenger side back to hot.
– I performed a ‘reset’ by disconnecting the battery for an hour
– Upon re-connection, the first thing I noticed was that the yellow Auto button light on the HVAC head was working. This wasn’t working before.
– The second thing I noticed that the fan wouldn’t come on. By fiddling with the buttons for 5 minutes, the fan came on.
– However, as soon as the fan came on, lo and behold, I got hot air coming from both driver and passenger side vents!
– To verify that this was not just a one-time thing, I turned the car off and then on.
– Immediately the original problem returned: cold air on driver side, hot air passenger side.
– The fan was also hard to start but I noticed that if I removed and put back the blower fuse, the fan would almost always start working again. (The fan is more of a red-herring….the temperature problem is the main thing I need to solve.)
– Btw, somewhere along the way the Auto button yellow light stopped working again.
– I noticed something weird: When HVAC was off, whenever a pushed a button to turn the unit on, I could hear the engine strain. It acted like, no matter what, the A/C compressor was turning on (even though the temperature was set to max-high and it was cold outside).
– Sure enough, I noticed the A/C clutch would engage whenever a button was pushed on the HVAC. I removed the fuse for the A/C clutch.
– From this point on, the compressor did not engage, however the driver side vent continued to blow “cool” (but not cold) air. Passenger side still hot.
– During testing, somehow, magically, after the HVAC was on for about 10 minutes, the driver side started blowing hot air.
– I turned car off and then on, and the problem returned immediately. The driver side blowing cold air, passenger side hot
– This morning on way to work, I waited to see if the driver side would magically start blowing hot. It didn’t.
– Then, after about 10 minutes, just on a hunch, I lowered the temperature as low as it could go, and then raised it again to max
– Voila, both sides start blowing hot air.
– My question: Is there a driver side thermostat separate from the passenger side? If so, it seems like the driver side thermostat always thinks that the temperature is “too hot” and thus turns the A/C on and then channels the A/C cold air into the driver side vents because it thinks it should be cooling the driver off even though it should be heating things up. Also, apparently, even when the A/C clutch is disconnected, it puts some flap in position to channel air from the A/C to the driver side vent, rather than channel air from the heater.
– At first thought, one might think that the driver side actuator that controls a flap may be at fault. However, if this were true, why would the HVAC be initiating the A/C clutch when it shouldn’t? If it was just a flap actuator problem and the thermostat was working properly, the A/C clutch would not be engaged, but the driver side would blow “cool” (outside) air.

Thoughts and suggestions much appreciated.
Duke
dumndac@comcast.net


Thank you for such a detailed description of your problem. 99% of the time when this issue occurs, the problem is in fact the Drivers Side Actuator.  They tend to stick and chew up the gears yet occasionally allowing it to work. The other 1 % of the time the door or linkage is damaged. This is quite common with all vehicles manufactured with electronic actuators.

Labor Time to Replace the Actuator is 1.0 Hours.

Actuator Replacement Procedure – Drivers Side

  • Disconnect the negative battery cable
  • Remove the instrument panel and instrument panel carrier
  • Unplug the temperature valve actuator harness connector
  • Remove the mounting screws, then temperature valve actuator.
  • Install in reverse order

Actuator Location Chart

Actuator location chart

 

Nov 272018
 

Ford Escape

Just had #4 fuel injector and spark plugs replaced. Added Gumout fuel injector cleaner to the next tank of gas as per directions. Time for a new tank of gas. Can I add another Gumout?


Yes, Shouldn’t need to add another but won’t hurt anything either. If you are using the Expert Series Gumout Fuel System Cleaner it is even advertised:

  • Best for maximized performance and fuel economy in one fill-up
  • Cleans direct and indirect fuel injectors, intake valves and ports, piston tops, cylinder heads, combustion chamber
  • Improves performance and maximizes gas mileage
  • Prevents future carbon buildup

Nov 142018
 

 Toyota Corolla

My car was hit on the left rear side while parked. The other car was parked behind me and was pulling out and hit my car. The damage to the body was repaired. After getting my car back I notice the steering wheel is turned slightly to the right even if the tires are straight. I don’t hear any grinding noises or any other kind of noises when I turn left or right. The brakes and engine work fine. The engine light is not on or any other warning light. I have driven it on the freeway and on the street. I don’t notice any problems. Is is safe to drive the car? What needs to be done to repair it? Thanks.


A front wheel or four wheel alignment would be the repair needed. During the alignment the discovery of a damaged part may come to light.

Nov 132018
 

This past Monday on my way to work, my car started bucking and the check engine light started flashing. I checked the code, it was P0301, Cylinder 1 misfire. Since then I have…

First I Changed the Ignition Coil Cylinder 1
Then I Changed the Spark Plug Cylinder 1
Changed the Fuel Injector Cylinder 1
Performed a Compression test Cylinder 1. Passed 185 psi
Visually inspected the wire harness
Visually inspected the vacuum hoses
Swapped the ECU

About 2 months, ago I installed a new fuel pump, fuel filter and pressure regulator.

When I first start the car, it runs fine. While it is still in park, I can rev ’til the cows come home without issue. When I put the car in gear and drive for a few seconds, I get the Flashing CEL and Misfire code(p0301 only) comes back every time. Also, I can feel the car missing, so I know its not an erroneous code. What should I try next?


I would recommend checking for intake manifold gasket leaks. It is a common failure that may cause a misfire problem. I have provided a diagnostic chart to help assist you.

Code P0301 Diagnostic Chart

P0301 Diagnostic Chart - 2009 Toyota

Nov 082018
 

Ford F150

I’ve been dealing with a parking brake light always on. We changed all my sensors and re soldered the wiring harness at the instrument cluster. I follow the wire all the way to the parking brake sensor and still cant find where the problem could be.


Parking brake light always on

You the provided wiring diagram to help diagnose your problem area.

*NOTE – the brake light will also illuminate when the brake fluid level is low or brake fluid level sensor is sticking. It will also illuminate if the park brake is not released completely. Sometimes this requires lifting up a bit on the park brake.

Parking Brake Light Switch wiring diagram – 2007 Ford F150

parking brake light wiring diagram 2007 Ford F150

 

Nov 042018
 

2010 Mercedes-Benz E350

I did a scan for codes with an OBDII Scantool for Mercedes only N code came up a10d00 saying power supply too low(stored) N. The next one read 9a4f13 right KEYLESS GO has a malfunction. THERE IS N OPEN CIRCUIT. CURRENT N STORED HOW DO I FIX IT


Did not find any reference to the second code you mentioned. However, there is a Technical Service Bulletin out related to this code A10D00. It refers a wiring harness being damaged in the area of the roof frame.  This could affect one or all of the following areas:

  • Overhead control panel nonfunctional
  • Bluetooth nonfunctional
  • Multi-function camera nonfunctional or , malfunctions

TSB Reference Number: LI54.18-P-048131, Date of Issue: November 20, 2009 – The entire TSB along with step by step corrective procedures and pictures are included in each manual. – Purchase Manual

Fault Code A10D00

Mercedes-Benz Code A10D00 Description – The power supply is too low.

Control Unit: MFK – Multi-function camera (A40/11)(MPC212)

 

Nov 042018
 

Dodge Grand Caravan

2003 Dodge Grand Caravan won’t turn over. New battery, new starter. All fuses and cables are good, ignition switch is good, the engine is not locked up. A few weeks ago the van would start fine then randomly shutoff going down the road. Then it could take between 2 minutes and 2 days to restart. It hasn’t started in a month now. What else could be the problem?


Sounds like a loose ground connection. But instead of jumping to that conclusion we have developed a step by step diagnostic chart just for this occasion.

Oct 252018
 

Nissan Titan

Have code 1273…Air fuel sensor…Where is it located and how to change?


Nissan Code P1273

Code P1273 Description:

Air Fuel Sensor 1 Heater Bank 1

Code P1273 Probable Causes:

  1. Sensor or solenoid faulty
  2. Connector terminal contact is damaged or corroded
  3. Wire harness – Check harness for correct voltage, open, short to ground or short to voltage
  4. Update control unit software – Check for the latest control unit update
  5. Powertrain or Engine Control Module faulty
  6. HO2S sensor contamination/damaged

Air Fuel Sensor Location

  • Sensor 1 Bank 1 – at left rear of engine (F65)
  • Sensor 1 Bank 2 – at right rear of engine compartment (F5)

Air Fuel Sensor Location Diagram

A closer look under the hood gives you a better view of the exact location of the A/F sensor.

A/F sensor location diagram

How to change Air Fuel Sensor

  1. Remove harness connector of air fuel ratio A/F sensor
  2. Remove the air fuel ratio A/F sensor is a 7/8 (22 mm) offset oxygen sensor socket.( the socket has a slot in one side to allow siding over the wiring harness.

Offset Oxygen Sensor Socket

  • Size: Common 6 point, 7/8 inch (22 millimeter) hex fits almost all oxygen sensors; 3/8″ drive for ratchets.
  • Design: This socket’s slotted design allows you to remove oxygen sensors with the wiring harness still attached, and the unique off set design of the T7822F Oxygen Sensor Wrench delivers maximum torque with maximum convenience! Made to increase torque on hard-to-remove O2 sensors and allows you to access tough spots, easily!

Shop Automotive

 

> > Need more, access a 2004 Nissan auto repair manual now!

Oct 252018
 

2005 GMC Yukon

Instrument Cluster, Radio, Door Locks, and Windows quit working on my 2003 GMC Yukon XL SLT 4×4. Believe it to be in the BCM. Need schematics, Connector Charts, and Diagnostic connector Diagram to Help in Diagnosing. Thanks, Patches


Here is the information that I have including wiring diagrams. A blown fuse that is used by all systems described would be the first thing I would look for. And it would be the most common cause if they all went out at the same time. Since the vehicle is more than 10 years old, rusted ground connections may also be a factor.

Body Control System Description and Operation

BCM Functions

The Body Control Module (BCM) performs multiple body control functions. The BCM can control devices directly connected to its outputs based on input information. The BCM evaluates this information and controls certain body control systems by commanding outputs on or off. The BCM control inputs can be:

  • Sensors and switches that are directly connected to the BCM
  • Class 2 serial data received from other control modules connected to the class 2 serial data link.

The BCM is also capable of controlling other vehicle systems that are not directly wired to the BCM. The BCM does this by sending specific messages on the class 2 serial data link. The control module capable of performing the required function will respond to the BCM message.

The BCM controls these functions:

  • Audible warnings
  • Automatic door locks
  • Automatic headlamp control
  • Interior lighting
  • Keyless entry (AUO option)
  • Passlock theft deterrent
  • Retained Accessory Power (RAP)

Serial Data Power Mode

On vehicles that have several control modules connected by serial data circuits, one module is the power mode master (PMM). On this vehicle the PMM is the Body Control Module (BCM). The BCM uses 3 signals from the ignition switch. These are the Ignition 0, Ignition 1, and Accessory.

To determine the correct power mode the BCM uses:

  • The state of these signals
  • Next , the sequence of switch closures received by the BCM
  • Finally, the status of the engine run flag

The chart indicates the power modes detected and transmitted by the BCM:

Correct Ignition Switch Inputs

Ignition Key Position

Power Mode Parameter

Engine Running

Sampled Ignition Signal State

Accessory

Ignition 1

Ignition 0

OFF Off-Awake or RAP No Inactive Off Off
UNLOCK Unlock or RAP Unlock No Inactive Off On
ACC Accessory No Active Off On
ON Run No Active On On
START Crank No Inactive On On
ON Run Yes Active On On

Fail-safe Operation

Since the operation of the vehicle systems depends on the power mode, there is a fail-safe plan in place should the BCM fail to send a power mode message. The fail-safe plan covers modules with discrete ignition signal inputs as well as those modules using exclusively serial data control of power mode.

Serial Data MessagesThe modules that depend exclusively on serial data messages for power modes stay in the state dictated by the last valid BCM message until they receive the engine status from the PCM. If the BCM fails, the modules monitor the serial data circuit for the engine run flag serial data. If the engine run flag serial data is true, indicating that the engine is running, the modules fail-safe to “Run”. In this state the modules and their subsystems can support all operator requirements. If the engine run flag serial data is false, indicating that the engine is not running, the modules fail-safe to “OFF-AWAKE”. In this state the modules are constantly checking for a change status message on the serial data circuits and can respond to both local inputs and serial data inputs from other modules on the vehicle.

Discrete Ignition SignalsThose modules that have discrete ignition signal inputs also remain in the state dictated by the last valid BCM message received on the serial data circuits. They then check the state of their discrete ignition input to determine the current valid state. If the discrete ignition input is active, B+, the modules will fail-safe to the “RUN” power mode. If the discrete ignition input is not active, open or 0 voltage, the modules will fail-safe to “OFF-AWAKE”. In this state the modules are constantly checking for a change status message on the serial data circuits and can respond to both local inputs and serial data inputs from other modules on the vehicle.

Body Control Module Programming

Introduction

The procedures below are designed to set-up the body control module (BCM) correctly during BCM related service. Before you start, read these procedures carefully and completely.

Important

The following procedures must be followed:

  1. BCM Programming
  2. Programming Theft Deterrent System Components, if equipped with Passlock System.

Programming the BCM

Important

After the procedure is completed, the personalization settings of the BCM are set to a default setting. Inform the customer that the personalization must be set again.

Programming Theft Deterrent System Components

Important

This procedure has to be performed only for vehicles equipped with Passlock System.

Perform the Programming Theft Deterrent System Components in Theft Deterrent after successfully finishing the Setup New BCM procedure. If the Programming Theft Deterrent System Components in the Theft Deterrent procedure is not performed after a BCM replacement, one of the following conditions will occur:

  • The vehicle will not be protected against theft by the PASSLOCK system.
  • The engine will not crank nor start.

Important

After programming, perform the following to avoid future misdiagnosis:

  1. Turn the ignition OFF for 10 seconds.
  2. Connect the scan tool to the data link connector.
  3. Turn the ignition ON with the engine OFF.
  4. Use the scan tool in order to retrieve history DTCs from all modules.
  5. Clear all history DTCs.

> > Need more, access a 2003 GMC auto repair manual now!