4th Generation (1993 - Present)

4.8 Miscellaneous

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Q: I heard that starting in 1999 GM has included a "black box" in the F-bodies and Corvettes that can tell what was happening in my car during a crash. Is this true, and if so, what does this black box record?

A: Yes, there is a black box, which records data from your car right before an accident. However this isn't new. Reports as far back as 1992 say there has been a device in these cars that record air bag and ABS activity during an accident. These devices were rumored to record data only on the moment of impact. More recently, these new devices record data up to 5 seconds before an impact. The things that are supposedly recorded are:

These devices were originally installed for field research purposes only. Having these devices in our cars gives GM more information about what happens to their cars during tests. This information can also help GM in legal situations where the effectiveness of their safety systems is in question. There has been no known cases thus far about this information being used against the driver of the vehicle. There is also no known way to defeat this system.

Q: Where can I get ramps for my F-Body?  None seem to work.

A: There are a couple of brands that work.  Rhino and Tru-Cut Automotive both sell ramps that will work.  Tru-Cut Automotive ramps have an availble (optional) "Extension Kit" that will allow for lowered vehicals to drive up them without scraping, and should be available at Pep Boys, K-Mart and Autozone to name a few.

Q: Why does the gas gauge plummet after the 1/2 mark?

A: The main reason for this, is that the gas tank is sort of shaped like a 'V'. The gauge just takes the depth of gas in the tank. As gas gets lower down in the tank, it's used faster than at the top of the tank due to the smaller volume. Thus gas is used quicker. The half way mark is actually only 1/3 full. So when the needle starts going towards the 'E', find the next gas station because 'E' is means EMPTY.

Q: Why does the trip odometer on my 1999 F-body sometimes reset back to 0 during cold weather? I know I didn't reset it.

A: There is a Technical Service Bulletin that you can refer to when taking you car into the dealer for it. Apparently its something wrong with the gauge cluster on the 1999s only. The TSB number is 99-08-49-009. The problem only exists when the car is cold and the battery drops below approximately 85% normal operating voltage. This causes the instrument cluster to reset itself. The regular odometer is not affected, and no other areas of the car are affected.

Q: How does the PASS-Key II system work?

A: PASS-Key II works with a small resistor chip embedded in your ignition key. This chip gives a certain resistance. When the ignition key is inserted into the car for the very first time at the factory the computer controller memorizes the exact resistance of that chip and will not start again w/o it.

This provides pretty good protection against all but the more sophisticated thief. A knowledgeable thief can get around it with the right equipment, but the time to steal goes up considerably.

Q: How can I display the error codes from a Service Engine Light?

A: According to the 1994 F-Carline Service Manual, page 6E-6 states in part:

"Although it is recommended that a diagnostic scan tool be used to read diagnostic trouble code(s), it may be possible to flash trouble codes on certain vehicles equipped with a 12 pin DLC connector."

If your car does not have the 12 pin DLC connector, you may not be able to manually "flash" your trouble codes. The language "may be possible" appears to suggest that this method should work with most, if not all, 12 pin DLC equipped cars.

   | 1  2  3   4   5   6 |
   | 7  8  9  10  11  12 |
   Pin 6 = Ground
       5 = Diagnostic Terminal
       2,12 = Serial data
       1 = TCC (Torque Converter Clutch Solenoid)


Some people with 94 models and on have had trouble using the following method, but it still won't hurt to try it. Ground Pin 5, the diagnostic terminal (into Pin 6), with the ignition off - then turn the ignition to the on position without starting the engine will flash the "Service Engine Soon" light in the following sequence. flash, pause, flash-flash, long pause flash, pause, flash-flash, long pause flash, pause, flash-flash, long pause Following this "12" code repeating three times will come

any trouble codes stored, flashing each of them three times. If you do not see the "12" flash three times, your diagnostic circuit could be defective. Otherwise you probably need a GM scan tool.

Some vehicles will display stored trouble codes, then "12" again, followed by energizing "most system controlled relays." The fuel pump relay will not energize. The idle air control valve will fully extend to enable checking minimum idle speed.


Starting the engine with pin 5 grounded will place the system in "Field Service Mode" Open loop will result in the Service Engine Soon light flashing more than twice per second. Closed loop will result in (1) Light flashing once per second, (2) Light staying off when running lean, and (3) Light staying on if running rich.


Turn the keyswitch to the off position. To clear any trouble codes, disconnect the power feed for 30 seconds. If this is done at the battery, and your car stereo is equipped and programmed with a four digit pin code, you may have to re-enter that as well to use your stereo again. A better place to remove power is at the fuse.


13. Open circuit at left oxygen sensor
14. High temperature indicated at engine coolant temp. sensor
15. Low temperature indicated at engine coolant temp. sensor
16. Low voltage at battery
17. Circuit fault/error at camshaft position sensor
18-20. N/A
21. High voltage at throttle position sensor
22. Low voltage at throttle position sensor
23. Low temperature at intake air temperature sensor
24. Fault in vehicle speed sensor
25. High temperature at intake air temperature sensor
26-27. N/A
28. Fault in transmission pressure switch assembly
29-32. N/A
33. High voltage (low vacuum) at manifold pressure sensor
34. Low voltage (high vacuum) at manifold pressure sensor
35. Idle speed can not be set to desired RPM
36. 24X signal
37. Fault in torque converter clutch brake switch
38. N/A
39. Fault in torque converter clutch circuit
40. N/A
41. Fault in ignition control timing circuit
42. Error in ignition control
43. Fault in knock sensor circuit
44. Left oxygen sensor lean
45. Left oxygen sensor rich
46. PASS-Key II circuit
47-50. N/A
51. PROM error
52. N/A
53. High voltage at battery
54. Low voltage at fuel pump
55-57. N/A
58. High temperature in transmission fluid
59. Low temperature in transmission fluid
60. N/A
61. A/C performance
62. N/A
63. Right oxygen sensor open circuit
64. Right oxygen sensor lean
65. Right oxygen sensor rich
66. Low A/C refrigerant pressure
67. A/C refrigerant pressure circuit error
68. A/C compressor relay short circuit
69. A/C compressor relay open circuit
70. High A/C refrigerant pressure
71. Low temperature at A/C evaporator
72. Signal error at vehicle speed sensor
73. High temperature at A/C evaporator
74. N/A
75. EGR solenoid #1 error
76. EGR solenoid #2 error
77. EGR solenoid #3 error
78. N/A
79. Transmission fluid hot
80. Transmission slipping
81. N/A
82. 3X signal, ignition control error
83. N/A
84. CAGS open circuit (95's and up only)
85. PROM error
86. Analog to digital converter error
87. EEPROM error
88-89. N/A
90. Torque converter clutch error
91-92. N/A
93. Pressure control solenoid Circuit current error
97. Voltage low in transmission system
98-99. Invalid PCM Program
Q: How can I determine a particular wire by its color and location?

A: The wires can be found as follows:

ignition harness
yellow (or purple)
ignition harness
ignition harness
orange(must enable)
right of dr.kick panel
White or white/black
ac coil/dist. assembly *
Power Lock
light blue**
either kick panel -
Power Unlock
Dark blue **
test from pass. sw.
Parking Lights
drivers kick panel
Door Trigger
behind left rear spkr
black conn. steer col.
L.F. Win Up/dwn
dark blue - brown
in drivers door
R.F. Win Up/dwn
light blue - tan****
in drivers door
Trunk Pin
same as door trigger
Trunk Release
at switch
Horn Trigger
black conn. st. column
Brake Wire
at brake switch
Reverse Lights
black conn. st. column
*White for the V6 and white/black for the V8.
**For keyless-entry versions, there are also red/black and orange/black lock wires in the passenger kick panel which are 5-wire and still mastered from the passenger switch.
***There are also gray/black in drivers kick panel (non-delay without connection for trunk).  The gray may be found in the harness below the speaker. So do not use the orange wires from dome light and door lock B+ circuits for 12V source as they shut off with timer.
****Bypass module for drivers window and connect directly to motor leads. In passenger door motor wires are dark blue and brown.







Crank Sensor (96 only)


IAC Coil A High

A/C Request



Trans Press Control Sol Low

IAC Coil A Low

Low Resolution Signal


Injector # 1

Ignition Positive Voltage

Right Rear O2 Low(96 only)

Distributor Ref Low


Injector # 4


Right Rear O2 High (96 only)



Injector # 6


IAC Coil B Low

Ignition Control


Injector # 7

Trans TCC PWM Sol

IAC Coil B High

Sensor GND


FP relay

Serial Data Class 2(96 only)

Right Front O2 Low

Trans 1-2 Shift Control



A/C Clutch Control

Right Front O2 High



EGR Control

MIL Control




Cooling Fan R2&3

EVAP Purge Sol.




Cooling Fan R1

Trans TCC Sol.

TCS Active signal



EBTCM TP sensor Signal

A/C Pressure sensor


Trans 2-3 Shift Control


Tachometer Out


Performance Mode Switch Signal

Skip Shift Control or 3-2 downshift


Air Pump Relay


Brake Signal Switch

Distributor Ignition feed


Trans Mode Lamp Control

Skip Shift Lamp

PNP Switch

+12V Battery




Trans Pressure Control Sol.

Sensor GND




Left Rear O2 low(96 only)





Left Rear O2 High(96 only)



Injector # 2


Left Front O2 Low

MAF signal


Injector # 5

Output/Field service Enable

Left Front O2 High

High Resolution Signal


Injector # 3


IAT sensor

A/C Clutch Status


Injector # 8

Knock Sensor

TP sensor



TCS Retard Control


MAP sensor

EVAP Vacuum Switch (96 only)



A/C Temp Sensor




Fuel Enable signal


ECT sensor














Trans Fluid Temp Sensor

Trans Range Signal A

5 Volt Reference




Trans Range Signal B

5 Volt Reference



Serial Data

Trans Range C

Ignition Positive Voltage


VSS Signal Low



Bat Positive voltage


VSS Signal High




Q: Why do the fans and service engine light come on just after cold start?

A: It's probably a blown air pump fuse (20 amp). Take the cover off the fuse box under the hood and locate the fuse. If it's blown, simply replace it. If it keeps blowing, then you probably have a faulty air pump which should be replaced as per the Technical Service Bulletin (#636502).

Q: How fast is my LT1 car?

A: Numbers are always different depending on who drove the car, how it was driven, the conditions of the track, how much weight was in the car, etc. And of course every car is not created equal. However these numbers, taken from the August '94 Chevy High Performance magazine, will give you an idea.

GM's advertised numbers are:

   0-60         1/4 mile                Top Speed               Model
   ---- ------------    ---------       ----------------
   6.1  14.8 @ 97          155          Z28 Coupe                
   6.3          14.8 @ 97          155          Trans Am Coupe M6        
   4.9          13.5 @ 104         160          Firehawk Coupe M6

Auto magazine reviews resulted in:

   Magazine  Date   Page  0-60  1/4 mile      Top Speed  Model
   --------  -----  ----  ----  ------------  ---------  -----------------
   C&D       01/93  121    5.4  14.2 @ 99        153     Formula Coupe M6
   MT        01/93   52    6.2  14.7 @ 96.9      n/a     Z28 Coupe M6
   MT        01/93   80    6.3  14.8 @ 97.6      n/a     Trans Am Coupe M6
   R&T       01/93         6.3  14.8 @ 95.5      n/a     Trans Am Coupe
   C&D       02/93   32    5.3  14.0 @ 100       154     Z28 Coupe M6
   C&D       02/93   32    5.5  14.2 @ 99        152     Formula Coupe M6
   MT        02/93   41    5.6  14.0 @ 98.8      n/a     Z28 Coupe M6
   MT        06/93   52    5.8  14.4 @ 97.9      151     Z28 Coupe M6
   MT        06/93   52    6.1  14.7 @ 97.2      152     Formula Coupe M6
   MT        08/93   82    5.8  14.4 @ 97.9      n/a     Z28 Coupe M6
   C&D       10/93         5.8  14.6 @ 97        104     Z28 Ragtop M6
   CR        10/93  682    6.6  15.1 @ 94        n/a     Trans Am Coupe A4
   MT        10/93   36    6.2  14.5 @ 96.2      n/a     Z28 Ragtop A4
   AW      11/22/93  19    5.8  14.3 @ 99        n/a     Z28 Coupe M6
   C&D       12/93         5.4  14.1 @ 101       156     Z28 Coupe M6
   R&T Spec  1994          6.2  14.8 @ 95.1      n/a     Z28 Coupe
   C&D       08/94         6.1  14.6 @ 96        153     Trans Am Coupe A4
   MT        08/94   41    5.7  14.2 @ 98.8      159.3   Z28 Coupe M6
   R&T Sport 1995    53    6.3  14.8 @ 95.5      n/a     Z28 Coupe M6
   R&T Sport 1995   130    6.7  15.1 @ 95.0      n/a     Formula Ragtop M6
   AM        06/95   53    n/a       n/a         152     Trans Am Coupe M6
   AM        06/95   56    n/a       n/a         155     Z28 Coupe M6
   R&T       06/95   79    6.4  14.9 @ 93.6      155.3   Z28 Coupe M6
   R&T       06/95   90    6.5  14.9 @ 93.9      157.8   Trans Am Coupe A4
   MT        07/95   51    5.6  14.0 @ 101.6     157     Trans Am Coupe M6
   MT        07/95   48    5.7  14.2 @ 100.2     155     Z28 Coupe M6
   C&D       06/97   50    5.3  13.9 @ 104       159     Trans Am Coupe M6 (1998)       
   CHP       04/98   40    n/a  13.34 @ 105.75   n/a     Z28 Coupe M6 (1998)

Other cars reviewed in the auto magazines include:

   Magazine      Date   Page  0-60  1/4 mile      Top Speed  Model
   --------     -----  ----  ----  ------------  ---------  ----------------
   C&D          06/93        9.2   17.0 @ 79        110     3.4 Camaro Coupe A4
   PP           06/93        6.2   14.7 @ 96.9      n/a     Z28 Coupe M6
   MT           07/93   49   4.9   13.5 @ 103.5     n/a     Firehawk Coupe M6
   MT           09/93   51   9.7   16.8 @ 77.6      n/a     3.4 Camaro Coupe A4
   CR           10/93   682  9.8   17.3 @ 79        n/a     3.4 Camaro Coupe A4
   C&D          05/94        8.9   16.8 @ 82        107     3.4 Camaro Coupe M5
   C&D          04/95        4.1   12.6 @ 114       183     Lingenfelter 383 M6
   MT           05/95   76   5.3   13.9 @ 103.6     n/a     Firehawk Coupe M6
   MT           05/95   102  7.4   15.7 @ 88.3      n/a     3800 Camaro Coupe A4
   MT Spec      05/95        4.9   13.4 @ 109.7     n/a     Rippie Camaro M6
   MT Spec      05/95        5.1   13.3 @ 113.1     n/a     Lingenfelter 383 M6
   MT Spec      05/95        5.1   13.2 @ 111.0     n/a     Paxton Camaro M6
   MT Spec      05/95        5.1   13.5 @ 107.4     n/a     Vortech Tran Am M6
   C&D          06/95        4.8   13.3 @ 109       172     Callaway Camaro C8 M6
   R&T          06/95   79   5.2   13.6 @ 110.2    177.1    Vortech Camaro M6
   R&T          06/95   89   4.5   12.7 @ 114.7    192.1    Lingenfelter 383 M6
   C&D          07/95        7.7   15.9 @ 86        114     3800 Camaro Coupe A4
Key to Magazines:
AM Automobile
AW Autoweek
C&D Car and Driver
CR Consumer Reports
MT Motor Trend
PP Petersen's Performance Cars
R&T Road & Track
CHP Chevy High Performance

Q: How fast is my LS1 car?

A: Once again, each car will perform differently, however various magazines have tested the new cars, and came up with quarter mile times between 13.6 and 13.9 stock for 1/4 mile times, and top speeds between 160 for the Camaro to 162 for the Trans Am WS6.
  Q: GM part numbers for common replacement parts.


Part Number:



Stock 48mm throttle body gasket


Intake manifold gasket set


Exhaust manifold gasket set


Stock .049" head gaskets


Head Gasket Kit (includes intake/heads/exhaust/etc)


Front cover (timing cover) gasket


Front cover Optispark Seal


Front cover crank seal


Water pump drive seal


Water pump bearing seal


Water pump gasket (2)


LT1 Water Pump


Centerbolt Valve Cover Gasket 


EGR Valve Gasket 


EGR Tube Gasket 


Oil Pan Gasket 


LT4 Extreme Duty Roller Timing Set 


LT4 Roller Timing Set Cam Gear (95+ LT1) 


LT4 Roller Timing Set Crank Gear (95+ LT1) 


LT4 Roller Timing Set Roller Chain (95+ LT1) 


LT1 Link-Chain Timing Set Crank Sprocket 


LT1 Link-Chain Timing Set Link Chain 


93-94 LT1 Link-Chain Timing Set Cam Sprocket 


95+ LT1 Link-Chain Timing Set Cam Sprocket 


Optispark Cap & Rotor Kit (inc bolts/cover/o-rings) 


left motor mount (LT1) 


right motor mount (LT1) 


Rear main seal housing gasket 


Pressure regulator seal kit 


1LE AC delete pulley 


94-95 LT1 PCM 


Knock module - LT1 95 Impala SS 


Knock module - LT1 F-Body OBD-I 


Knock module - LT1 F-body OBD-II 


Knock module - LT1 Corvette 


Knock module - LT4 Corvette 


Knock module - LT1 Impala 


Pinion seal 


Pinion crush sleeve 


Pinion nut 


Series 3 Carrier ABS Reluctor (Speed sensor reluctor) 


Pinion bearing outer assembly 


Pinion bearing assembly-inner 


Carrier bearing assembly 


Differential cover gasket 


Mobil 1 75W-90 Synthetic Gear Lube GL-5 


93-97 f-body stock driveshaft (steel 2.5"d wall 0.065"t 40.8"l 16 lbs) 


1LE 87-92 f-body driveshaft (aluminum 2.75"d wall 0.130"t 12.2 lbs) 


3.5" MAF sensor 


1 bar MAP sensor


Q: What is Dal's phone number?


Van Devere Olds Co.

300 West Market St.

Akron, Ohio 44303


fax: 330-253-1370

URL: http://www.vandevere.com/

Email: lockitup@bright.net


Q: What can I expect from a specific mod?

A: Various mods give various results when combined with other mods.  Sometimes the results are good, sometimes they are bad.  Be extra careful with exhaust and intake mods as oversizing on either will result in a power loss.   Below is a listing of some of the list members cars, and their results.   Whenever possible, if the same car is tested under different mods, they are listed.   While these are very informative, please realize that your results will probably be different depending on fuel pressure, environment, etc.

1.        All tests below are taken at the rear-wheels unless otherwise stated.
2.        All tests are corrected using SAE standards.
3.        R Means that the car was re-tested again with a different setup.
Car Owner                         R     Year/Model                       Mods                                                                                                         RWHP        RWTQ
---------------                        --     -----------------------             ------------------------------------------------------------------------------            ---------        ---------
Bruce Yey                                   1995 Z28 M6                    Homemade Air Intake, 3'rd Gen Flowmaster Muffler,                         276.7           317.2
                                                                                                HPP, 160 Degree Therm.
Bruce Yey                          Y     1995 Z28 M6                     Same as above, but added 1.6 Crane Gold Rockers                            283.0           322.6
Steve Profio                              1998 Z28 M6                     Bone Stock                                                                                                300.5           326.4
Jody Shapiro                             1997 Z28 M6                     Vortech 7# S/C, 160 Therm., Hypertech Blower Pgm                         363.4           357.0
                                                                                                Borla Cat-Back (no plate)
Jody Shapiro                     Y     1997 Z28 M6                     Same as above, but with the middle Borla plate                                  348.5           344.7
David Fontaine                         1998 Z28SS M6                 Bone stock, no SLP Options, single outlet exhaust                           300.0           316.9
Paul Britton                               1997 Z28 A4                      Bone stock                                                                                                225.6           243.0
David Wilson                           1996 Z28 M6                     MTI Cold air, Air foil, MTI Underdrive pulley,                                   305.5           331.7
                                                                                                Ford SVO 24# Inj., SLP Flywheel, 1LE driveshaft,
                                                                                                MSD6AL, NOS #5115,GMPP 1.6RR,Crane 10308-1 springs
David Wilson                           1996 Z28 M6                     Same as above, but with NOS                                                                407.3           549.2
Ehrich Koch                              1996 T/A WS6 M6           Borla (1.75" plate), airfoil, Crane 99846 springs                                   292.0           320.0
                                                                                                1.6 Comp Cams Pro-Magnum Rockers
Joshua Andrews                      1995 Formula M6              Edelbrock Cat-Back,FIPK,Accel 300+,160 Therm.,                             298.8           260.8
                                                                                                AFPR (42 psi),HPP+
James Nance                             1996 Z28 M6                     K&N filter, 1LE intake elbow and driveshaft                                       258.5           301.4
Allen Woolley                          1995 Z28 M6                     Borla Cat-Back,AS&M Headers,3.73's, Accel Coil                             283.0           318.0
                                                                                                1LE driveshaft,Crane HI6TR,Jacob wires,
                                                                                                HPP+ and Custom Blower pgm,Random Cat.
Allen Woolley                  Y     1995 Z28 M6                     Same as above, but with Vortech 7# and Crane 1.6RR                      396.8           391.2
Mike Graham                             1995 Z28 A4                      Decoma Cat-Back, !TB, !MAF and K&N Filter                                   269.2           315.3
Keith Lockliear                 Y     1996 T/A WS6 M6           Bone Stock                                                                                                277.1           305.4
Keith Lockliear                 Y     1996 T/A WS6 M6           Same as above, but w/1LE driveshaft                                                   278.2           310.4
Keith Lockliear                 Y     1996 T/A WS6 M6           Same as above, but w/Hypertech Underdrive Pulley                         279.4           315.5
Keith Lockliear                 Y     1996 T/A WS6 M6           Same as above, but w/HPP+, 160 Thermostat                                     283.2           317.1
Keith Lockliear                 Y     1996 T/A WS6 M6           Complete setup: Borla cat-back, driveshaft,pulley                             295.0           324.3
                                                                                                air-foil, HPP+, 160 Therm., Synthetic Transmission and
                                                                                                rear-end fluid, Hypertech AFPR, !TB Coolant, Turbo
                                                                                                Shops Power Loader II Program, K&N Filter