Page 37 – Sparky's Answers

1997 Maxima Code P0340, No Start or Start and Stall

This 1997 Nissan Maxima was towed in from another shop after unsuccessful repair attempts. I am not sure how many shops it has been to. Tried to crank vehicle, it spit and coughed and jumped and carried on but I managed to get it to fire a little by depessing the gas pedal to the floor {clear flood mode}.

I checked the plugs and they were black and fouled out and several showed signs of gas blowby at the insulator seal, so I installed a new set of plugs. cranked the engine and it ran. After a couple of minutes it had cleared up and was running good. Ran a few more minutes for good measure. Turned engine off and recranked. It cranked and ran fine. Did the other shops miss something this simple? I don’t know? Cranked it several times and no problems, time for a test drive. Backed the car out of the shop and took off on a test drive. Right, got 20 feet and it stalled and would not crank back up. Kind of figured it, plugs would be too easy.

Got the scanner out and checked codes P0325 and P0340 were stored. The P0325 code is for a knock sensor and will not cause the engine to not run, so I was going to concentrate on the P0340 code. The code P0340 is for a cam sensor error. Checked the cam sensor and it had been replaced.

I needed to check the continuity of the wires between the cam sensor and the ECM. The ECM is located under the center of the dash as shown below.

I removed the white plastic cover to have better access to the wiring.

I had to use an ohm meter hooked to both ends of the two wires. While the harness (shown below) was wiggled. Sure enough one of the two wires was broken. In doing this repair I had to try several things before I came up with a way to repair this vehicle in a cost effective way. The harness costs about two thousand dollars plus installation.

I clipped the two wires near the ECM harness connector. Then started to look for a way to run new wires. My first choice would be to attach new wires to the old, with splicing connectors and pull them through the harness, then splice at the other end. This would not work as the wires are glued into the grommet at the firewall. It would be virtually impossible for me to identify the two wires at the ECM so you will need to access that information from Mitchell 1. There is a link at the top right of this page.

My next choice was to try and run the new wires through, hopefully another grommet. The problem is the only other thing I could see was the a/c drain tube. Running new wires there did not seem like a good idea. To get a really good look the evaporator case needed to come out. Recovered the refrigerant and removed all of the interior mounting screws.

Problem, the evaporator case will not come out past the glove box support brace. A very close look and I determined that if I removed the metal brace. Then cut the plastic between the two screw holes on each side that the evaporator case would come out. When reassembling the two screws would hold the plastic pieces together. It appears to me that an engineer actually designed it to be cut, if the evaporator case needed to be removed.

The cut on the right side of the glove box opening.

At least now I can see where the wires go through the firewall. I felt around and decided that I could go through the original grommet. On the lower right side, as it is viewed in the pictures below.

I have a special tool for doing this procedure. The tool is similar to a screwdriver but it has hole running through it. Using the sharp end I pierced the grommet and ran the wire through the hole in the tool.

With the wire run through the hole in the tool and to the other side of the firewall, I pulled the tool back out over the remaining wire on the inside of the vehicle.

A close up look at the hole in the handle.

The sharp end of the tool that easily pierces the rubber grommet.

I purchased a special piece of shielded, twisted, pair wire cable from an aircraft supplier. The first thing that had to be done was to loosen the shielding and move it down the cable assembly enough to stagger the joints. I did have to split it length way also.

After prepping the cable, I connected it to the factory harness connector. I staggered the joints.

Heated the tubing and shrank it into place.

Twisted the remaining cable, around the repair.

Pulled the shielding back up and around the spliced wires, then used tape to hold it in place.

I repeated the process at the other end near the computer. I then taped and wire tied the new cable to the old harness. One thing that I learned through this whole experience is that if at all possible do not pull the harness out from under the dash. It is looped to the top of the ECM and is almost impossible to get it back into place. The reason I had pulled it out was so that I could pull the new wiring through the old harness and just attach it on both ends. The glue in the fire wall grommet prevented me from doing this, so in the end, there was no reason to pull the harness loose that far.

A closer look at where the wiring breaks inside the harness. My experience on this one also convinced me to not open the harness to actually see the damage. Way too hard to get it all back together that way. Just make sure the wiring is the problem with a meter and/or piggy back a new harness to the outside of the old harness and attach it at both ends.

1999 Ford F150, P0306 Misfire Cylinder #6

This 1999 Ford F150 Came in with a misfire on cylinder number 6. No big deal except that the spark plugs, spark plug wires and coil assembly have already been changed with quality parts. The other thing I noticed was that the misfire did not come in until the engine speed reached about 1500 RPMs. Diagnosing this wound up being easy after I thought about it for a little while.

To confirm the cause, note the RPM range when the misfire comes in. Disconnect the EGR valve vacuum hose and plug the hose end. Bring the RPMs back into the misfire range as previously noted. If the misfire is gone the EGR tubes are restricted.

To correct the condition, remove the upper intake and inspect the EGR orifices in the lower intake openings. I did not bother listing how to remove the upper intake, as that information is available in any repair manual for this vehicle.

The picture may be too dark but there are tubes with holes in them where I am pointing to.

A small piece of wire and a good shop vacuum and the debris (at least in my case) comes out easily. The same condition could have caused a misfire on any of the cylinders. Just coincidence that the #6 tube was open and the others were highly restricted. The one open tube was causing all of the exhaust air from the opened EGR valve to be dumped into cylinder #6. Thus causing a lean misfire on that cylinder.

Some new gaskets, put it back together and this one is done.

2003 Chevrolet Impala, Battery Goes Dead

This 2003 Chevrolet Impala came in with the complaint that the battery would go dead after a couple of days of driving. The customer stated that the battery light had been coming on and going off for a while now. The alternator has been replaced three times and the battery twice. The battery light was on, so I checked the basic charging system first. Hooked up my tester.

Cranked the engine and checked the meter. Not charging.

I decided to check the alternator output at the back of the alternator.

Well, twenty plus volts is pretty high. I have seen this problem multiple times on many different vehicles. The cause is an open circuit between the alternator and the battery.

This was the voltage with the engine off. A slight amount of voltage was present, so I was thinking a loose connection. Rather than a completely open circuit caused by a blown fuse or fusible link.

Looking over the engine compartment, I saw that the alternator output lead headed back to the starter. Pretty obvious that there is a problem there. Click on the picture below to enlarge for a better view.

I removed the nut and lock washer so that I could clean the mess up and check for deeper damage.

The ring terminals were arced up but they cleaned up well.

After thoroughly cleaning the ring terminals I found only cosmetic damage. I reassembled the wiring to that battery post on the starter. Installed a new nut and washer.

Check for voltage at the alternator with the engine off.

With the engine on.

I rechecked at the battery with my big tester and all was well, except that the battery was down, as indicated by slightly high amp reading and slightly low voltage reading.

A little time on the battery charger and this one will be ready to go.

2004 Ford Expedition, P0305 Misfire Cylinder #5

This 2004 Ford Expedition came in with a code P0305, misfire cylinder #5. The customer already had the spark plugs changed out a few days ago, but his misfire was back. Time to get to cylinder #5 coil. I removed the two bolts that held the engine cover in place.

After the top engine cover was removed, I could now get to the power steering bracket that covers the #5 coil assembly.

There are three bolts that hold the bracket on place. All 8 mm heads.

Now, unplug the coil and only one 7 mm headed bolt holds the coil in place.

Pull the coil out and inspect.

There is the misfire, right on the side of the coil. A new coil assembly and all is well.

This coil should have never been reinstalled when the spark plugs were changed. As a rule of thumb for myself, if there is a specific misfire on one cylinder, that coil is going to be replaced, when the tune up work is done. At the very least it will be moved to the easiest location for removal. This one was pretty easy but never put a suspect coil back in #3, #4, #7 or #8.

1997 GMC C1500 Pickup, No Blower Part 3

Last of a three part post on Chevrolet and GMC full sized truck and suv blower issues.

The best place to start testing is at the blower motor. Key on and blower set to high. Check for power on the purple wire and ground on the black wire. If power is missing on the purple wire recheck while switching to reach of the lower speeds.

If no power is found at all on the purple wire, go to the blower relay and check for the signals listed on the part 2 post. If all signals to the blower relay are good except on the dark blue wire, disconnect the blower resistor and check for the proper signals from the blower switch as outlined in the part 2 post.

If power on the red wire or ground on the black wires are missing check the integrity of the three wire connector to the right of the glove box opening.

If the connector is okay but power is still missing on the red wire check the A/C fuse in the underhood fuse box. If the ground signal is missing and the three wire connector is good, repair the loose black ground wire at the rear of the passenger side cylinder head. If you cannot find it in yourself to man up and fix the ground at the rear of the passenger side cylinder head, cut the black wire under the dash that goes through the firewall and attach it to a known good ground.

If you were missing any blower switch signals at the relay and or the resistor, remove the a/c control panel and check the circuits there as outlined in the part 1 post.

Lastly due to age and the type of plastics things may/will break when working with the a/c control panel. The main hold down for the blower switch will hold it in place even if the smaller retainers break. If the latches that hold the control panel to the dash break, the panel can be attached with small drill point screws.

1997 GMC C1500 Pickup, No Blower Part 2

Second part of a multi-part repair post on GM truck blower systems. The blower resistor and the blower relay are located on top of the heater case. Behind the glove box.

After opening the glove box, there may be two retention systems present. Sometimes there are plastic cables that are attached to the sides of the glove box. There will be a small latch that has to be lifted so that the cable can slide out of the slot in the glove compartment. Next there will be the plastic and rubber bump stop on the right rear corner of the glove box. That bump stop has to be flexed inward to allow the glove box to drop down fully. Once the glove box is fully down it will slide off of the hinge pins.

Okay with the glove box out of the way you can see the relay and the blower resistor locations.

A closer look shows the relay to the left and the resistor harness connector to the right. Testing at the relay is as follows.

Red wire, 12 volt battery constant power supplied from A/C (maxi fuse) in the underhood fuse box.
Black wire, constant ground supply from location at the rear of the passenger side cylinder head assembly under the hood.
Purple wire, power supply from blower relay to the blower motor.
Dark Blue wire, switched power supply from the blower switch, through the blower resistor. The dark blue wire and the purple wire contacts inside the relay are connected to each other at all times, other than high blower operation.
Orange wire, switched power from the blower switch in the high position only. Power on this wire energizes the relay coil which in turn closes the contacts between the red and purple wires. Giving full battery power to the blower motor.

Testing at the resistor is as follows.

Yellow wire, switched power from the blower switch, on the Low speed position, to the blower resistor where it travels through the three resistor coils and out on the dark blue wire.
Tan wire, switched power from the blower switch, on the M1 position, to the blower resistor where it travels through two resistor coils and out on the dark blue wire.
Light blue wire, switched power from the blower switch on the M2 position, to the blower resistor where it travels through one resistor coil and out on the dark blue wire.
Dark blue wire, variable power, from the blower resistor to the blower relay. While at rest the contacts between the dark blue wire and the purple wire are connected inside the relay. The varying power sent on the dark blue wire, goes through the relay and comes out of the relay, on the purple wire. This signal controls all of the speeds except for high.

If you need this resistor please click here.

This connector located at the right side of the glove box opening frequently burns out. When it is damaged power on the red wire or ground on the black wire will be lost. many times both wires will be burnt.

The two wires that go to the blower motor. During testing the purple wire will have varying voltage depending on the speed selected. The black wire will have ground at all times. If power is found on the black wire, while it is connected to the blower motor, it will be due to power bleeding through the motor windings from the purple wire and a Missing or Loose Ground. The common locations for the ground problem are at the rear of the passenger side cylinder head and at the connector shown above.

The ground connection at the blower motor.

This rubber cover has to be removed in order to replace the blower motor.

The orange piece in the center of the picture is the power connection to the blower motor. The color may vary.

The harness where the black wire travels through the firewall to be attached to the rear of the passenger cylinder head, under the hood.

1997 GMC C1500 Pickup, No Blower Part 1

This 1997 GMC C1500 came in for some other a/c service and I asked the customer about the blower working. He said it worked fine and asked why I wanted to know. I told him of the endless requests that I get for information on the blower systems on these trucks and how I wanted to meet my readers needs. He told me to take it apart and take as many pictures as I wanted to.

This information applies to 1995, 1996, 1997, 1998, 1999 old body style C1500 & K1500 Chevrolet and GMC pickup trucks and SUV’s, 1995-2000 C2500 and K2500 trucks and SUV’s, 1995-2002 C3500 trucks, and 1995-2001 K3500 trucks. SUV’s include Escalade, Suburban, Tahoe and Yukon. I will have to break this information into several posts, so please be patient. This part will deal with the blower switch and its signals. To gain access to the blower switch the dash face has to be removed.

Grasp the edge of the dash face panel and pull towards the steering wheel.

When the panel is pulled out far enough, depress the locking tab on the headlight switch wiring and unplug the harness.

As the face panel is worked loose, the switches to the left of the radio and a/c controls will need to be disconnected. Most of the time if the small panel will pull loose from the main panel it will be easier to work with.

It is easier to do all of this with the shifter handle pulled all of the way down to the D1 position.

As the trim panel is rolled away from the dash, the plastic will need to be flexed slightly in order to remove the face panel.

Now that the trim panel is out of the way, the a/c control head can be removed. There are two plastic clips that need to be released. One on each side.

Then the a/c control head assembly can be pulled from the dash.

The latch that holds the harness to the blower switch is on the underside of the assembly. Depress the latch and unplug the harness.

This harness connector is okay of course, but many times the brown and orange wires will be burnt. If there is any heat discoloration, the switch and the harness connector must be replaced at the same time or the condition will return very quickly.

The entire control panel does not have to be replaced if only the blower switch is damaged. There is one screw that holds the retaining plate in place. Remove the screw and retaining plate. There will be two smaller plastic clips that hold the switch to the main housing. Most of the time they will break due to age. That is okay as long as the main retaining plate and screw are installed after the switch replacement. If you need to order this switch please click here.

Terminal “A” = Light Blue wire, Speed M2, switched power to blower resistor
Terminal “B” = Tan wire, Speed M1, switched power to blower resistor
Terminal “C” = Yellow wire, Speed Low switched to blower resistor
Terminal “D” = Dark Green wire, A/C disable signal, switched power to connector C3, terminal “4”
Terminal “E” = Empty
Terminal “F” = Empty
Terminal “G” = Brown wire, 12 volt ignition supply from fuse #12 (25 amp)
Terminal “H” = Orange wire, Speed High, switched power to terminal “C2” of blower relay

2003 Chevrolet Trailblazer, Blower Not Working Any Speeds, Brake & ABS Lights On

This 2003 Chevrolet Trailblazer came in with the complaint that the blower would not work on any speed and that the Brake and ABS lights stay on. Since I have seen this problem before, I knew right where to go to test. then ignition switch. The first thing that has to be done is to remove the tilt lever handle. Some just pull straight out but this one was a little difficult so I used a screwdriver for leverage.

After the lever is pulled past the detent it comes out easily the rest of the way.

Now the trim panels under the dash have to come out. Two screws, 7mm, for the black hush panel under the dash.

With the black panel down there are two screws that hold the bottom of the knee bolster panel.

Two at the top of the panel.

Then the panel will unsnap. Someone has already been here. The spring clips are missing.

Now there is a soft piece of rubber trim at the rear of the lower cover. It needs to be worked loose of the lower cover. Then carefully unsnap the lower cover and work it loose from the column and the soft rubber piece in the rear. Some models may require removing the steering wheel to get the cover off and some may have screws in the underside of the lower cover.

Now that the switch wiring is exposed. Check for constant battery power on the red wire as shown below.

Turn the ignition on and check for power on the orange wire. We have just diagnosed a faulty ignition switch.

To remove the switch, I first gently pulled the wiring for the key buzzer and /or antitheft antenna out of the retainer as shown below.

There is a special GM tool for releasing the ignition switch retainers but I just use a couple of pocket screwdrivers. There are two white spring loaded pins that have to be pushed in to allow the switch to come out.

You can now see the two pins exposed as I pulled the switch down.

GM says to remove the lock cylinder and use a tool to fully rotate the inner mechanism but I don’t bother. I just make sure the ignition is off. Key out. Pull the switch down and note the position of the gear teeth. DO NOT rotate the gear teeth. Adjust the teeth on the new switch to match the old switch position.

The wiring harness lock is a little difficult to release. You are supposed to depress the locking tab.

I was having a problem so wedged my screwdriver between the switch housing and lifted it instead. If something breaks, I would rather break an old part that is being replaced, instead of the latch on the harness connector. Makes sense, right?

I checked the harness connector for damage and all was okay.

Maybe a better view of the plug in connection to the switch.

I adjusted the gear teeth to the same position. I also compared them one behind the other to check the alignment.

The new switch on the right with the gray cover. To purchase the new updated ignition switch please click here.

Slide the new switch into place until the spring loaded locking tabs click into place.

Plug the wiring harness back up to the switch. Positioned the rest of the wiring back into the retainer on the side of the switch.

Cranked the engine and checked the blower and all is well. Time to finish installing the rest of the parts.

To see the video for this repair please click here.

This ignition switch fits the following vehicles, however the repair procedure may vary between these vehicles.

2001-2005 Pontiac Aztek
2002-2004 Oldsmobile Bravada
2002-2007 Buick Rendezvous
2002-2009 Chevrolet Trailblazer
2002-2009 GMC Envoy
2003-2006 Cadillac Escalade
2003-2006 Chevrolet SSR
2003-2006 Chevrolet Suburban
2003-2006 GMC Savana
2003-2006 GMC Yukon
2003-2007 Chevrolet Silverado
2003-2007 Chevrolet Express
2003-2007 GMC Sierra
2003-2007 Hummer H2
2003-2008 Isuzu Ascender
2004-2006 Chevrolet Tahoe
2005-2007 Buick Rainier
2006 Chevrolet Avalanche
2006-2009 Saab 9-7X

2003 Chevrolet Impala, No Crank Condition

This 2003 Chevrolet Impala came in withe the complaint that it would not crank, starter would not work. It turned out to be a very simple problem. The car was purchased from a county auction and driven to my customers house. He started cleaning the vehicle up and had noticed a lot of extra wiring on the car. He didn’t want the excess wiring just hanging all over the place so he decided to clean it up a little. He could not get the nut off of the stud in the picture below, so he just clipped all of the wiring close to the stud. Notice all of the clipped wires around the stud? Enlarge the picture and take a closer look. If you don’t see the problem, just wait I will show it to you. It took quite a bit of effort but I was able to get the nut loose and remove the excess terminals and wiring.

Now, the real problem is a little clearer. In his haste to clean up the excess wiring, my customer clipped a factory wire (fusible link).

A new terminal and a little solder. The crimp is sufficient to connect the terminal but I like to seal the exposed end of the crimp.

Applied a little heat to my previously installed heat shrink tubing.

Installed the new ring terminal and wire back on to the stud.

Returned the factory cover back to its position on the stud and this one is fixed. I doubt that this will be a very common problem but I thought it might be of interest to those thinking of cutting wires.

General Motors Computer Hardware Requirements for Programming GM Vehicles

After an exhausting morning of trying to get my computer set up for TIS 2 Web Programming, this is what I found. Forget about using a modern computing system built for a consumer. At this time GM’s programming system will only work with 32 bit systems. GM recommends for successful programming to only use a professional grade Windows 32 bit operating system. I have used consumer grade hardware for programming in the past and have been told by others that it will work. However, GM states that they do not support those systems. The following is taken from ” General Motors Dealer Infrastructure Guidelines, ver 2010.07.01″. I have highlighted certain terms in red that I found important.

“Please Note the Following:

Dealerships may choose processor speeds, memory capacities, audio adapters and hard drive
capacities which exceed the recommended specifications based on needs and product
availability.

General Motors does not support the following: AMD or Pentium IV or lower processors, 64 Bit
Operating Systems or consumer grade hardware.

Techline does not support Windows XP Mode / Windows Virtual PC on Windows 7 Professional.

Techline does not support Windows XP Tablet Edition.

General Motors does support the following: Intel Dual Core, Intel Core 2 duo / quad,
Intel i3 / i5 / i7, Intel Atom (HP Mini 5102 High Definition), Business grade hardware,
Vista Business 32 bit SP1, and XP Professional SP3 (until December 31, 2010).

For Service Programming (SPS) purposes, a dealership may be asked to purchase a USB drive
to perform programming on a Radio/Navigation or Instrument Panel Cluster (IPC) system.

The following specification should be used when purchasing the USB drive:

USB 2.0 compliant flash drive 512 MB or greater

Techline application updates require Windows Administrative access

General Motors estimates the life cycle of a Desktop PC, Laptop or Notebook on average is three
(3) years.

Techline requires one (1) PC for every two (2) technicians”

Click here to read the entire document.
Nowhere on this page of “does and does not support hardware and operating systems”, does it state that it will work with Windows 7 Professional, 32 bit.

My biggest gripe, about this whole thing, is this not published on the TIS 2 Web programming website?

Click here to see for yourself.