service engine soon light
07-23-2001, 01:13 PM
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I have a 96 with 36,000 miles. Saturday the service engine soon light came on while I was low on fuel. Filled it up and drove about 25-30 miles and it went off. Drove it saturday night and put about 100-150 miles on it. I get in it this morning and while I am on my way to work the light comes on again. Can I get the trouble code by using the paper clip method on a 96. Any help would be greatly appreciated.
07-23-2001, 02:09 PM
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Yes you can. Use positions 4 and 12. These are the 4th ones from the left of the terminal block as you face it. You then use the gage buttons to the right of the gages to cycle thru all the diagnostics. But my 96 can do the same thing without setting any codes if the gas cap is not put on extremely tight. Take it completely off and then apply a lot of pressure as you are tightening it before the built in clicking feature starts working. Good luck. Frank
07-23-2001, 02:19 PM
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The amount of codes you can get with the paper clip method are limited. Here is a list of them:
This is a summary of manual code display and clearing. It is for my '96 OBDII system. The information came from the HELM manual of this year of production. I hope in helps some of my fellow Vette owners.
The easiest and best way is to have a SCAN TOOL and plug into the data connector, but without that, you can retrieve some of your codes by:
DIAGNOSTIC MODE
To enter the diagnostic mode, ground terminal "12" of the Data Link Connector (located just forward of your right knee) and the ground terminal is "4 and 5". The Data Link Connector is numbered from Left to Right and then Top to Bottom starting with 1 and ending with 16. This makes the LEFT most holes numbers 1 and 9, and the RIGHT most holes 8 and 16.
Your speedometer, odometer, and the trip monitor located on the instrument cluster will display information while in the diagnostic mode.
The buttons on the Driver Information Center (DIC) are used to send instructions to the CCM when in the diagnostic mode.
FUEL INFO - Previous Values
ENG MET - Next Value
GAUGES - Previous Test
TRIP ODO - Next Test
FUEL RESET - Previous Module
TRIP RESET - Next Module
IMPORTANT
If the A/C fuse is blown, the Central Control Module (CCM) will not enter diagnostic mode.
After turning the ignition "ON" the CCM will display and Diagnostic Trouble Codes (DTC's) and the module for which they apply in an automatic DTC display sequence.
CCM is module 1
PCM (Power Train Control Module) is module 4
RTD (Real Time Damping) is module 7
ABS/TCS EBTCM (Antilock Brake System, Traction Control System, Electronic Brake and Traction Control Module) is module 9
DERM (Diagnostic Energy Reserve Module) is module A
During the automatic display sequence, each DTC is displayed for three seconds, followed by a one-second pause before the next DTC is displayed.
There is a three-second pause between the DTC display sequence for each module. The end of the DTC list for each module is indicated by "-----" being displayed in the speedometer. If there is a problem with the module, the speedometer will display "Err " when being interrogated.
The module being interrogated is indicated on the trop monitor, and the DTC are displayed on the speedometer.
When all DTC's have been displayed for all modules, the trip monitor will display 1.0 and the speedometer will be blank. At this time, you are in the manual mode and the CCM is waiting for input from the DIC buttons mentioned above.
DISPLAY ON THE TRIP MONITOR
1.0 Waiting for Instructions
1.1 Display CCM DTC's
1.2 Display CCM Data
1.3 Display CCM Inputs Status
1.4 Clear CCM Outputs
1.7 Clear CCM DTC's
4.0 Waiting for Instructions (PCM)
4.1 Display PCM DTC's
4.7 Clear PCM DTC's
7.0 Waiting for Instructions (RTD)
7.1 Display RTD DTC's
7.7 Clear RTD DTC's
9.0 Waiting for instructions (ABS/TCS)
9.1 Display ABS/TCS DTC's
9.7 Clear ABS/TCS DTC's
A.0 Waiting for Instructions (DERM)
A.1 Display DERM DTC's
A.7 Clear DERM DTC's
DISPLAY CCM DTC'S
DIAGNOSTIC MODE 1.1
To display CCM DTC's select the "Display DTC's " mode by pressing the "TRIP/ODO" button until "1.1' appears in the trop monitor area of the cluster. Then, press the "ENGMET" button to display the first DTC. Continue pressing the "ENG/MET" button to display additional CCM DTC's until the end is indicated by "---". A "C12" indicates no stored DTC's for the CCM.
CCM DTC LIST
12 On-Board Diagnostics operational No DTC's
13 DIC Switch Open or Shorted to B+
14 DIC Switches Shorted to ground
16 ignition 3 fuse circuit open
21 horn relay coil shorted to b+ or CCM Internal open
22 rear defogger relay coil shorted or open
24 courtesy lamp relay coil shorted to B+
25 courtesy lamp relay coil circuit open
26 LCD blanking control circuit shorted to B+
27 LCD Blanking Control Circuit Open or Shorted to Ground
31 LCD Data Circuit Shorted to B+ or CCM Internal Open
32 LCD Data Circuit Open or Shorted to Ground
33 Data Clock Circuit Shorted To B+ or CCM Internal Open
34 Data Clock Circuit Open of Shorted to Ground
35 Data Strobe Circuit Shorted To B+ of CCM Internal Open
36 Data Strobe Circuit Open of Shorted to Ground
37 M Clock Circuit Shorted to B+ or CCM Internal Open
38 M Clock Circuit open or shorted to Ground
51 PASS Key Invalid Key Detection
52 PASS Key Detection Circuit Shorted to B+
53 PASS Key Detection Circuit Open of Shorted to B+
54 FEDS Fuel Enable Failure
61 PASS Key #2 Programming Resistance out or range
62 PASS Key #2 Programming Resistance high
63 PASS Key #2 Programming Resistance low
71 LCD Dimming Output Circuit Shorted to B+
72 LCD Dimming circuit open or shorted to ground
73 LED display dimming output circuit shorted to B+ or CCM internal open
74 LED display dimming output circuit open or shorted to ground
81 invalid vehicle configuration
LTPWS manual Diagnosis
Ground Terminal 6 to 5 at the DLC connector with the ignition in the on position. This will enable the SERVICE LTPWS light to flash any stored DTC's
The SERVICE LTPWS light will flash in a logical sequence to depict a two digit DTC associated with each low tire or fault condition.
Each DTC displayed will consist of a number of flashes representing the first digit, followed by a short pause, followed by a number of flashes representing the second digit and then a long pause indicates the end of the DTC. All DTC's stored in memory will be displayed three times before proceeding to the next DTC. DTC 12 will always precede and DTC's stored in the receiver memory and will be continuously displayed if no DTC's are present.
DTC's for LTPWS
23 - Low Tire DTC Rt. rear
24 - Wheel Sensor DTC Rt. Rear
33 - Low Tire DTC Lt. rear
34 - Wheel Sensor DTC Lt. Rear
43 - Low Tire DTC Lt. front
44 - Wheel Sensor DTC Lt. front
53 - Low Tire DTC Rt. front
54 - Wheel Sensor DTC Rt. front
99 - Receiver/control module does not get any wheel sense signals for three consecutive thirty minute periods with the ignition in the on position
In case of actual failure the DTC's will be set after the vehicle has been driven at least 25mph for approx. 30 seconds or longer and tire pressure is below 25psi
Pressure sensor faults will be set after the receiver/control module as seen one sensor transmission.
Clearing LTPWS faults
1. Turn ignition off
2. Make sure jumper is removed
3. Turn ignition on
4. Short pins 5 and 6 three times within 10 seconds.
E-mail me or call at 520-305-0763 for an interpretation of any codes you get. I will type this list up at a latter time.
You will need to clear any codes or they will be forever stored in memory and will continue to flash the "check engine" light. If you have no problems in the next 40-50, some test cycles the codes will clear automatically.
CLEARING CCM DTC'S
1. With ignition OFF ground terminal "12" of the DLC connector.
2. Turn ignition ON
3. Press trip/ODO button in DIC until "1.7" appears in the trip monitor area of the instrument cluster.
4. Press ENG/MET button on DIC and hold until "----" appears in speedometer area of cluster, this will clear CCM DTC's
5. Turn ignition OFF
6. Turn ignition ON and verify that no CCM DTC's are present.
7. Turn ignition OFF, then remove DLC ground to terminal "12"
Electronic Automatic Air Conditions Diagnosis
When you get a system fault in this part of the car, you will have an LED blink above the air directional button (vent/vent and floor etc.) for approximately one minute. Diagnostic Trouble Codes (DTC's) will store.
Entering the diagnostic mode is pretty easy. Just push and hold the fan "up" arrow and fan "down" arrow at the same time for 5 seconds. The Liquid Crystal Display (LCD) will show "-00". Now push "AUTO FAN" and the LCD will show any DTC's stored in the programmer.
00 No system faults
01 Temperature Door Motor Circuit Fault
02 Door Motor Circuit Fault
03 Outside Air Temperature Sensor Open
04 Outside Air Temperature Sensor Short
05 Inside Air Temperature Sensor Open
06 Inside Air Temperature Sensor Short
07 Sun Load Temperature Sensor Open
09 Low Refrigerant Detected
10 Serial Data Failure
P.s. This is on my '96
This is a summary of manual code display and clearing. It is for my '96 OBDII system. The information came from the HELM manual of this year of production. I hope in helps some of my fellow Vette owners.
The easiest and best way is to have a SCAN TOOL and plug into the data connector, but without that, you can retrieve some of your codes by:
DIAGNOSTIC MODE
To enter the diagnostic mode, ground terminal "12" of the Data Link Connector (located just forward of your right knee) and the ground terminal is "4 and 5". The Data Link Connector is numbered from Left to Right and then Top to Bottom starting with 1 and ending with 16. This makes the LEFT most holes numbers 1 and 9, and the RIGHT most holes 8 and 16.
Your speedometer, odometer, and the trip monitor located on the instrument cluster will display information while in the diagnostic mode.
The buttons on the Driver Information Center (DIC) are used to send instructions to the CCM when in the diagnostic mode.
FUEL INFO - Previous Values
ENG MET - Next Value
GAUGES - Previous Test
TRIP ODO - Next Test
FUEL RESET - Previous Module
TRIP RESET - Next Module
IMPORTANT
If the A/C fuse is blown, the Central Control Module (CCM) will not enter diagnostic mode.
After turning the ignition "ON" the CCM will display and Diagnostic Trouble Codes (DTC's) and the module for which they apply in an automatic DTC display sequence.
CCM is module 1
PCM (Power Train Control Module) is module 4
RTD (Real Time Damping) is module 7
ABS/TCS EBTCM (Antilock Brake System, Traction Control System, Electronic Brake and Traction Control Module) is module 9
DERM (Diagnostic Energy Reserve Module) is module A
During the automatic display sequence, each DTC is displayed for three seconds, followed by a one-second pause before the next DTC is displayed.
There is a three-second pause between the DTC display sequence for each module. The end of the DTC list for each module is indicated by "-----" being displayed in the speedometer. If there is a problem with the module, the speedometer will display "Err " when being interrogated.
The module being interrogated is indicated on the trop monitor, and the DTC are displayed on the speedometer.
When all DTC's have been displayed for all modules, the trip monitor will display 1.0 and the speedometer will be blank. At this time, you are in the manual mode and the CCM is waiting for input from the DIC buttons mentioned above.
DISPLAY ON THE TRIP MONITOR
1.0 Waiting for Instructions
1.1 Display CCM DTC's
1.2 Display CCM Data
1.3 Display CCM Inputs Status
1.4 Clear CCM Outputs
1.7 Clear CCM DTC's
4.0 Waiting for Instructions (PCM)
4.1 Display PCM DTC's
4.7 Clear PCM DTC's
7.0 Waiting for Instructions (RTD)
7.1 Display RTD DTC's
7.7 Clear RTD DTC's
9.0 Waiting for instructions (ABS/TCS)
9.1 Display ABS/TCS DTC's
9.7 Clear ABS/TCS DTC's
A.0 Waiting for Instructions (DERM)
A.1 Display DERM DTC's
A.7 Clear DERM DTC's
DISPLAY CCM DTC'S
DIAGNOSTIC MODE 1.1
To display CCM DTC's select the "Display DTC's " mode by pressing the "TRIP/ODO" button until "1.1' appears in the trop monitor area of the cluster. Then, press the "ENGMET" button to display the first DTC. Continue pressing the "ENG/MET" button to display additional CCM DTC's until the end is indicated by "---". A "C12" indicates no stored DTC's for the CCM.
CCM DTC LIST
12 On-Board Diagnostics operational No DTC's
13 DIC Switch Open or Shorted to B+
14 DIC Switches Shorted to ground
16 ignition 3 fuse circuit open
21 horn relay coil shorted to b+ or CCM Internal open
22 rear defogger relay coil shorted or open
24 courtesy lamp relay coil shorted to B+
25 courtesy lamp relay coil circuit open
26 LCD blanking control circuit shorted to B+
27 LCD Blanking Control Circuit Open or Shorted to Ground
31 LCD Data Circuit Shorted to B+ or CCM Internal Open
32 LCD Data Circuit Open or Shorted to Ground
33 Data Clock Circuit Shorted To B+ or CCM Internal Open
34 Data Clock Circuit Open of Shorted to Ground
35 Data Strobe Circuit Shorted To B+ of CCM Internal Open
36 Data Strobe Circuit Open of Shorted to Ground
37 M Clock Circuit Shorted to B+ or CCM Internal Open
38 M Clock Circuit open or shorted to Ground
51 PASS Key Invalid Key Detection
52 PASS Key Detection Circuit Shorted to B+
53 PASS Key Detection Circuit Open of Shorted to B+
54 FEDS Fuel Enable Failure
61 PASS Key #2 Programming Resistance out or range
62 PASS Key #2 Programming Resistance high
63 PASS Key #2 Programming Resistance low
71 LCD Dimming Output Circuit Shorted to B+
72 LCD Dimming circuit open or shorted to ground
73 LED display dimming output circuit shorted to B+ or CCM internal open
74 LED display dimming output circuit open or shorted to ground
81 invalid vehicle configuration
LTPWS manual Diagnosis
Ground Terminal 6 to 5 at the DLC connector with the ignition in the on position. This will enable the SERVICE LTPWS light to flash any stored DTC's
The SERVICE LTPWS light will flash in a logical sequence to depict a two digit DTC associated with each low tire or fault condition.
Each DTC displayed will consist of a number of flashes representing the first digit, followed by a short pause, followed by a number of flashes representing the second digit and then a long pause indicates the end of the DTC. All DTC's stored in memory will be displayed three times before proceeding to the next DTC. DTC 12 will always precede and DTC's stored in the receiver memory and will be continuously displayed if no DTC's are present.
DTC's for LTPWS
23 - Low Tire DTC Rt. rear
24 - Wheel Sensor DTC Rt. Rear
33 - Low Tire DTC Lt. rear
34 - Wheel Sensor DTC Lt. Rear
43 - Low Tire DTC Lt. front
44 - Wheel Sensor DTC Lt. front
53 - Low Tire DTC Rt. front
54 - Wheel Sensor DTC Rt. front
99 - Receiver/control module does not get any wheel sense signals for three consecutive thirty minute periods with the ignition in the on position
In case of actual failure the DTC's will be set after the vehicle has been driven at least 25mph for approx. 30 seconds or longer and tire pressure is below 25psi
Pressure sensor faults will be set after the receiver/control module as seen one sensor transmission.
Clearing LTPWS faults
1. Turn ignition off
2. Make sure jumper is removed
3. Turn ignition on
4. Short pins 5 and 6 three times within 10 seconds.
E-mail me or call at 520-305-0763 for an interpretation of any codes you get. I will type this list up at a latter time.
You will need to clear any codes or they will be forever stored in memory and will continue to flash the "check engine" light. If you have no problems in the next 40-50, some test cycles the codes will clear automatically.
CLEARING CCM DTC'S
1. With ignition OFF ground terminal "12" of the DLC connector.
2. Turn ignition ON
3. Press trip/ODO button in DIC until "1.7" appears in the trip monitor area of the instrument cluster.
4. Press ENG/MET button on DIC and hold until "----" appears in speedometer area of cluster, this will clear CCM DTC's
5. Turn ignition OFF
6. Turn ignition ON and verify that no CCM DTC's are present.
7. Turn ignition OFF, then remove DLC ground to terminal "12"
Electronic Automatic Air Conditions Diagnosis
When you get a system fault in this part of the car, you will have an LED blink above the air directional button (vent/vent and floor etc.) for approximately one minute. Diagnostic Trouble Codes (DTC's) will store.
Entering the diagnostic mode is pretty easy. Just push and hold the fan "up" arrow and fan "down" arrow at the same time for 5 seconds. The Liquid Crystal Display (LCD) will show "-00". Now push "AUTO FAN" and the LCD will show any DTC's stored in the programmer.
00 No system faults
01 Temperature Door Motor Circuit Fault
02 Door Motor Circuit Fault
03 Outside Air Temperature Sensor Open
04 Outside Air Temperature Sensor Short
05 Inside Air Temperature Sensor Open
06 Inside Air Temperature Sensor Short
07 Sun Load Temperature Sensor Open
09 Low Refrigerant Detected
10 Serial Data Failure
P.s. This is on my '96
