4th Generation (1993 - Present)
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.
THE CONNECTOR
-----------------------
| 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)
DISPLAYING THE TROUBLE CODES
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.
FIELD SERVICE MODE
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.
CLEARING THE TROUBLE CODES
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.
TROUBLE CODES
13. Open circuit at left oxygen sensor14. High temperature indicated at engine coolant temp. sensor15. Low temperature indicated at engine coolant temp. sensor16. Low voltage at battery17. Circuit fault/error at camshaft position sensor18-20. N/A21. High voltage at throttle position sensor22. Low voltage at throttle position sensor23. Low temperature at intake air temperature sensor24. Fault in vehicle speed sensor25. High temperature at intake air temperature sensor26-27. N/A28. Fault in transmission pressure switch assembly29-32. N/A33. High voltage (low vacuum) at manifold pressure sensor34. Low voltage (high vacuum) at manifold pressure sensor35. Idle speed can not be set to desired RPM36. 24X signal37. Fault in torque converter clutch brake switch38. N/A39. Fault in torque converter clutch circuit40. N/A41. Fault in ignition control timing circuit42. Error in ignition control43. Fault in knock sensor circuit44. Left oxygen sensor lean45. Left oxygen sensor rich46. PASS-Key II circuit47-50. N/A51. PROM error52. N/A53. High voltage at battery54. Low voltage at fuel pump55-57. N/A58. High temperature in transmission fluid59. Low temperature in transmission fluid60. N/A61. A/C performance62. N/A63. Right oxygen sensor open circuit64. Right oxygen sensor lean65. Right oxygen sensor rich66. Low A/C refrigerant pressure67. A/C refrigerant pressure circuit error68. A/C compressor relay short circuit69. A/C compressor relay open circuit70. High A/C refrigerant pressure71. Low temperature at A/C evaporator72. Signal error at vehicle speed sensor73. High temperature at A/C evaporator74. N/A75. EGR solenoid #1 error76. EGR solenoid #2 error77. EGR solenoid #3 error78. N/A79. Transmission fluid hot80. Transmission slipping81. N/A82. 3X signal, ignition control error83. N/A84. CAGS open circuit (95's and up only)85. PROM error86. Analog to digital converter error87. EEPROM error88-89. N/A90. Torque converter clutch error91-92. N/A93. Pressure control solenoid Circuit current error97. Voltage low in transmission system98-99. Invalid PCM Program Q: How can I determine a particular wire by its color and location?
A: The wires can be found as follows:
UNIT/OPERATION |
WIRE COLOR |
POL |
WIRE LOCATION |
12V |
red |
+ |
ignition harness |
Starter |
yellow (or purple) |
+ |
ignition harness |
Ignition |
Pink |
+ |
ignition harness |
Accessory |
orange(must enable) |
+ |
right of dr.kick panel |
Tach |
White or white/black |
|
ac coil/dist. assembly * |
Power Lock |
light blue** |
5wi |
either kick panel - |
Power Unlock |
Dark blue ** |
5wi |
test from pass. sw. |
Parking Lights |
brown |
|
drivers kick panel |
Door Trigger |
white |
- |
behind left rear spkr |
Headlights |
yellow |
+ |
|
Wiper |
green |
+ |
black conn. steer col. |
L.F. Win Up/dwn |
dark blue - brown |
A |
in drivers door |
R.F. Win Up/dwn |
light blue - tan**** |
A |
in drivers door |
Trunk Pin |
same as door trigger |
- |
|
Trunk Release |
black |
+ |
at switch |
Horn Trigger |
black |
- |
black conn. st. column |
Brake Wire |
yellow |
+ |
at brake switch |
Reverse Lights |
green |
+ |
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.|
|
Red |
Blue |
Grey |
Black |
|
1 |
Crank
Sensor (96 only) |
GND |
IAC
Coil A High |
A/C
Request |
|
2 |
GND |
Trans
Press Control Sol Low |
IAC
Coil A Low |
Low
Resolution Signal |
|
3 |
Injector
# 1 |
Ignition
Positive Voltage |
Right
Rear O2 Low(96 only) |
Distributor
Ref Low |
|
4 |
Injector
# 4 |
|
Right
Rear O2 High (96 only) |
|
|
5 |
Injector
# 6 |
|
IAC
Coil B Low |
Ignition
Control |
|
6 |
Injector
# 7 |
Trans
TCC PWM Sol |
IAC
Coil B High |
Sensor
GND |
|
7 |
FP
relay |
Serial
Data Class 2(96 only) |
Right
Front O2 Low |
Trans
1-2 Shift Control |
|
8 |
|
A/C
Clutch Control |
Right
Front O2 High |
VSS
Out |
|
9 |
EGR
Control |
MIL
Control |
|
|
|
10 |
Cooling
Fan R2&3 |
EVAP
Purge Sol. |
|
|
|
11 |
Cooling
Fan R1 |
Trans
TCC Sol. |
TCS
Active signal |
|
|
12 |
EBTCM
TP sensor Signal |
A/C
Pressure sensor |
|
Trans
2-3 Shift Control |
|
13 |
Tachometer
Out |
|
Performance
Mode Switch Signal |
Skip
Shift Control or 3-2 downshift |
|
14 |
Air
Pump Relay |
|
Brake
Signal Switch |
Distributor
Ignition feed |
|
15 |
Trans
Mode Lamp Control |
Skip
Shift Lamp |
PNP
Switch |
+12V
Battery |
|
16 |
|
|
Trans
Pressure Control Sol. |
Sensor
GND |
|
17 |
|
|
Left
Rear O2 low(96 only) |
|
|
18 |
GND |
|
Left
Rear O2 High(96 only) |
|
|
19 |
Injector
# 2 |
|
Left
Front O2 Low |
MAF
signal |
|
20 |
Injector
# 5 |
Output/Field
service Enable |
Left
Front O2 High |
High
Resolution Signal |
|
21 |
Injector
# 3 |
|
IAT
sensor |
A/C
Clutch Status |
|
22 |
Injector
# 8 |
Knock
Sensor |
TP
sensor |
|
|
23 |
TCS
Retard Control |
|
MAP
sensor |
EVAP
Vacuum Switch (96 only) |
|
24 |
|
A/C
Temp Sensor |
|
|
|
25 |
Fuel
Enable signal |
|
ECT
sensor |
|
|
26 |
|
|
|
|
|
27 |
|
|
|
|
|
28 |
|
Trans
Fluid Temp Sensor |
Trans
Range Signal A |
5
Volt Reference |
|
29 |
|
|
Trans
Range Signal B |
5
Volt Reference |
|
30 |
|
Serial
Data |
Trans
Range C |
Ignition
Positive Voltage |
|
31 |
VSS
Signal Low |
|
|
Bat
Positive voltage |
|
32 |
VSS
Signal High |
|
GND |
|
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).
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
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.
A:
|
Part
Number: |
Description: |
|
10105379 |
Stock
48mm throttle body gasket |
|
12524653 |
Intake
manifold gasket set |
|
12552469 |
Exhaust
manifold gasket set |
|
10168457 |
Stock
.049" head gaskets |
|
12369145 |
Head
Gasket Kit (includes intake/heads/exhaust/etc) |
|
10128293 |
Front
cover (timing cover) gasket |
|
12552428 |
Front
cover Optispark Seal |
|
10128316 |
Front
cover crank seal |