LT 1 codes
Le Mans Master
Joined: Mar 2004
Posts: 5,107
Likes: 171
From: Dublin CA
Thread Starter
Burning Brakes
Joined: May 2004
Posts: 1,230
Likes: 27
From: Athens Ohio
Melting Slicks
Joined: Mar 2008
Posts: 2,351
Likes: 222
From: Delta B.C. Canada
2023 C7 of the Year Finalist - Unmodified
2019 C4 of Year Finalist (appearance mods)
2015 C4 of Year Finalist
Codes for the 92 are:
13 Oxygen sensor voltage stays between 0.35 and 0.55 volts for 60 seconds. Engine was at normal operating temperature and had been running for at least 2 minutes after start with a throttle angle above 5%.
14 Coolant temperature sensor signal indicates a temperature of over 266? F.
15 Coolant temperature sensor signal indicates a temperature colder than -56? F.
16 A low resolution pulse was not detected by ECM within 720 high resolution timing pulses.
21 TPS voltage was above 2.5 volts for 3 seconds when the engine was running, or when the TPS was above 4.8 volts at any time.
22 TPS voltage was under 0.23 volts when the engine was running.
23 Inlet air temperature sensor signal showed an air temperature below -31? F for 60 seconds after the engine has been running for 4 minutes.
24 Vehicle speed was 0 MPH when engine speed was between 900 and 3000 RPM and throttle position angle was less than 2% for 5 seconds.
25 Inlet air temperature sensor signal showed an air temperature over 302? F for 12 seconds after the engine has been running for 4 minutes.
26 ECM detected the wrong potential voltage at the #1 quad-driver module circuit for 20 seconds.
27 ECM detected the wrong potential voltage at the #2 quad-driver module circuit for 3 seconds.
28 ECM detected the wrong potential voltage at the #3 quad-driver module circuit for 3 seconds.
32 EGR open command did not change the fuel mixture when the command was given during off idle operation. EGR opening should cause the mixture to be slightly richer because of the low oxygen content of the exhaust gas.
33 MAP sensor signal voltage was too high (low vacuum) for 1 second when throttle opening was under 3% and engine speed was above 500 RPM.
34 MAP sensor signal voltage was too low (high vacuum) when engine speed was under 700 RPM, or when TPS was greater than 20% with an engine speed above 700 RPM.
36 ECM detected less than 60 high resolution timing pulses between each low resolution pulse for 5 consecutive cycles.
41 EST circuit voltage was above 4.6 volts when engine speed was under 1500 RPM.
42 The EST circuit voltage was below 0.5 volts when engine speed was below 3000 RPM.
43 One or both of the knock sensors were either open or grounded for 5 seconds.
44 Left oxygen sensor voltage was under 0.2 volts for 50 seconds of closed loop operation.
45 Left oxygen sensor voltage was over 0.7 volts for 50 seconds when the throttle angle was above 4% during closed loop operation.
51 PROM error. (Means PCM problem)
52 Engine oil temperature was below -31? F after engine had been running for 30 minutes.
53 ECM detected a battery voltage either above 17.1 volts or below 8 volts.
55 ECM detected a lean oxygen sensor voltage for 3 seconds during the power enrichment modes of operation.
62 Engine oil temperature sensor indicated an oil temperature above 284? F after engine had been running for 30 minutes.
63 Right oxygen sensor was open showing a steady voltage between 0.35 and 0.55 volts for 60 seconds after the engine had been running for at least 2 minutes.
64 Right oxygen sensor voltage was below 0.2 volts for 50 seconds of closed loop operation.
65 Right oxygen sensor voltage was above 0.7 volts for 50 seconds of closed loop operation when the throttle angle was above 4%.
66 A/C pressure sensor circuit was either open or shorted showing a voltage below 0.12 volts or above 4.86 volts for 10 seconds.
67 ECM did not detect an A/C system pressure change of more than 9 psi when A/C clutch was engaged.
68 ECM detects voltage on the A/C status line for more than 20 seconds after ECM has disengaged the A/C relay.
69 ECM did not detect any voltage on A/C status line for 20 seconds after ECM had commanded A/C ON.
72 2nd or 3rd gear switch was open for 1.5 seconds when vehicle speed was above 30 MPH with engine speed greater than 5000 RPM and a throttle angle above 70%.
13 Oxygen sensor voltage stays between 0.35 and 0.55 volts for 60 seconds. Engine was at normal operating temperature and had been running for at least 2 minutes after start with a throttle angle above 5%.
14 Coolant temperature sensor signal indicates a temperature of over 266? F.
15 Coolant temperature sensor signal indicates a temperature colder than -56? F.
16 A low resolution pulse was not detected by ECM within 720 high resolution timing pulses.
21 TPS voltage was above 2.5 volts for 3 seconds when the engine was running, or when the TPS was above 4.8 volts at any time.
22 TPS voltage was under 0.23 volts when the engine was running.
23 Inlet air temperature sensor signal showed an air temperature below -31? F for 60 seconds after the engine has been running for 4 minutes.
24 Vehicle speed was 0 MPH when engine speed was between 900 and 3000 RPM and throttle position angle was less than 2% for 5 seconds.
25 Inlet air temperature sensor signal showed an air temperature over 302? F for 12 seconds after the engine has been running for 4 minutes.
26 ECM detected the wrong potential voltage at the #1 quad-driver module circuit for 20 seconds.
27 ECM detected the wrong potential voltage at the #2 quad-driver module circuit for 3 seconds.
28 ECM detected the wrong potential voltage at the #3 quad-driver module circuit for 3 seconds.
32 EGR open command did not change the fuel mixture when the command was given during off idle operation. EGR opening should cause the mixture to be slightly richer because of the low oxygen content of the exhaust gas.
33 MAP sensor signal voltage was too high (low vacuum) for 1 second when throttle opening was under 3% and engine speed was above 500 RPM.
34 MAP sensor signal voltage was too low (high vacuum) when engine speed was under 700 RPM, or when TPS was greater than 20% with an engine speed above 700 RPM.
36 ECM detected less than 60 high resolution timing pulses between each low resolution pulse for 5 consecutive cycles.
41 EST circuit voltage was above 4.6 volts when engine speed was under 1500 RPM.
42 The EST circuit voltage was below 0.5 volts when engine speed was below 3000 RPM.
43 One or both of the knock sensors were either open or grounded for 5 seconds.
44 Left oxygen sensor voltage was under 0.2 volts for 50 seconds of closed loop operation.
45 Left oxygen sensor voltage was over 0.7 volts for 50 seconds when the throttle angle was above 4% during closed loop operation.
51 PROM error. (Means PCM problem)
52 Engine oil temperature was below -31? F after engine had been running for 30 minutes.
53 ECM detected a battery voltage either above 17.1 volts or below 8 volts.
55 ECM detected a lean oxygen sensor voltage for 3 seconds during the power enrichment modes of operation.
62 Engine oil temperature sensor indicated an oil temperature above 284? F after engine had been running for 30 minutes.
63 Right oxygen sensor was open showing a steady voltage between 0.35 and 0.55 volts for 60 seconds after the engine had been running for at least 2 minutes.
64 Right oxygen sensor voltage was below 0.2 volts for 50 seconds of closed loop operation.
65 Right oxygen sensor voltage was above 0.7 volts for 50 seconds of closed loop operation when the throttle angle was above 4%.
66 A/C pressure sensor circuit was either open or shorted showing a voltage below 0.12 volts or above 4.86 volts for 10 seconds.
67 ECM did not detect an A/C system pressure change of more than 9 psi when A/C clutch was engaged.
68 ECM detects voltage on the A/C status line for more than 20 seconds after ECM has disengaged the A/C relay.
69 ECM did not detect any voltage on A/C status line for 20 seconds after ECM had commanded A/C ON.
72 2nd or 3rd gear switch was open for 1.5 seconds when vehicle speed was above 30 MPH with engine speed greater than 5000 RPM and a throttle angle above 70%.
Burning Brakes
Joined: Mar 2008
Posts: 881
Likes: 24
From: Coquitlam BC
Helpful post Harv! Hope to see you @ the Waterfront Show in N.Van. on Sunday! Be there by 9AM! 
Codes for the 92 are:
13 Oxygen sensor voltage stays between 0.35 and 0.55 volts for 60 seconds. Engine was at normal operating temperature and had been running for at least 2 minutes after start with a throttle angle above 5%.
14 Coolant temperature sensor signal indicates a temperature of over 266? F.
15 Coolant temperature sensor signal indicates a temperature colder than -56? F.
16 A low resolution pulse was not detected by ECM within 720 high resolution timing pulses.
21 TPS voltage was above 2.5 volts for 3 seconds when the engine was running, or when the TPS was above 4.8 volts at any time.
22 TPS voltage was under 0.23 volts when the engine was running.
23 Inlet air temperature sensor signal showed an air temperature below -31? F for 60 seconds after the engine has been running for 4 minutes.
24 Vehicle speed was 0 MPH when engine speed was between 900 and 3000 RPM and throttle position angle was less than 2% for 5 seconds.
25 Inlet air temperature sensor signal showed an air temperature over 302? F for 12 seconds after the engine has been running for 4 minutes.
26 ECM detected the wrong potential voltage at the #1 quad-driver module circuit for 20 seconds.
27 ECM detected the wrong potential voltage at the #2 quad-driver module circuit for 3 seconds.
28 ECM detected the wrong potential voltage at the #3 quad-driver module circuit for 3 seconds.
32 EGR open command did not change the fuel mixture when the command was given during off idle operation. EGR opening should cause the mixture to be slightly richer because of the low oxygen content of the exhaust gas.
33 MAP sensor signal voltage was too high (low vacuum) for 1 second when throttle opening was under 3% and engine speed was above 500 RPM.
34 MAP sensor signal voltage was too low (high vacuum) when engine speed was under 700 RPM, or when TPS was greater than 20% with an engine speed above 700 RPM.
36 ECM detected less than 60 high resolution timing pulses between each low resolution pulse for 5 consecutive cycles.
41 EST circuit voltage was above 4.6 volts when engine speed was under 1500 RPM.
42 The EST circuit voltage was below 0.5 volts when engine speed was below 3000 RPM.
43 One or both of the knock sensors were either open or grounded for 5 seconds.
44 Left oxygen sensor voltage was under 0.2 volts for 50 seconds of closed loop operation.
45 Left oxygen sensor voltage was over 0.7 volts for 50 seconds when the throttle angle was above 4% during closed loop operation.
51 PROM error. (Means PCM problem)
52 Engine oil temperature was below -31? F after engine had been running for 30 minutes.
53 ECM detected a battery voltage either above 17.1 volts or below 8 volts.
55 ECM detected a lean oxygen sensor voltage for 3 seconds during the power enrichment modes of operation.
62 Engine oil temperature sensor indicated an oil temperature above 284? F after engine had been running for 30 minutes.
63 Right oxygen sensor was open showing a steady voltage between 0.35 and 0.55 volts for 60 seconds after the engine had been running for at least 2 minutes.
64 Right oxygen sensor voltage was below 0.2 volts for 50 seconds of closed loop operation.
65 Right oxygen sensor voltage was above 0.7 volts for 50 seconds of closed loop operation when the throttle angle was above 4%.
66 A/C pressure sensor circuit was either open or shorted showing a voltage below 0.12 volts or above 4.86 volts for 10 seconds.
67 ECM did not detect an A/C system pressure change of more than 9 psi when A/C clutch was engaged.
68 ECM detects voltage on the A/C status line for more than 20 seconds after ECM has disengaged the A/C relay.
69 ECM did not detect any voltage on A/C status line for 20 seconds after ECM had commanded A/C ON.
72 2nd or 3rd gear switch was open for 1.5 seconds when vehicle speed was above 30 MPH with engine speed greater than 5000 RPM and a throttle angle above 70%.
13 Oxygen sensor voltage stays between 0.35 and 0.55 volts for 60 seconds. Engine was at normal operating temperature and had been running for at least 2 minutes after start with a throttle angle above 5%.
14 Coolant temperature sensor signal indicates a temperature of over 266? F.
15 Coolant temperature sensor signal indicates a temperature colder than -56? F.
16 A low resolution pulse was not detected by ECM within 720 high resolution timing pulses.
21 TPS voltage was above 2.5 volts for 3 seconds when the engine was running, or when the TPS was above 4.8 volts at any time.
22 TPS voltage was under 0.23 volts when the engine was running.
23 Inlet air temperature sensor signal showed an air temperature below -31? F for 60 seconds after the engine has been running for 4 minutes.
24 Vehicle speed was 0 MPH when engine speed was between 900 and 3000 RPM and throttle position angle was less than 2% for 5 seconds.
25 Inlet air temperature sensor signal showed an air temperature over 302? F for 12 seconds after the engine has been running for 4 minutes.
26 ECM detected the wrong potential voltage at the #1 quad-driver module circuit for 20 seconds.
27 ECM detected the wrong potential voltage at the #2 quad-driver module circuit for 3 seconds.
28 ECM detected the wrong potential voltage at the #3 quad-driver module circuit for 3 seconds.
32 EGR open command did not change the fuel mixture when the command was given during off idle operation. EGR opening should cause the mixture to be slightly richer because of the low oxygen content of the exhaust gas.
33 MAP sensor signal voltage was too high (low vacuum) for 1 second when throttle opening was under 3% and engine speed was above 500 RPM.
34 MAP sensor signal voltage was too low (high vacuum) when engine speed was under 700 RPM, or when TPS was greater than 20% with an engine speed above 700 RPM.
36 ECM detected less than 60 high resolution timing pulses between each low resolution pulse for 5 consecutive cycles.
41 EST circuit voltage was above 4.6 volts when engine speed was under 1500 RPM.
42 The EST circuit voltage was below 0.5 volts when engine speed was below 3000 RPM.
43 One or both of the knock sensors were either open or grounded for 5 seconds.
44 Left oxygen sensor voltage was under 0.2 volts for 50 seconds of closed loop operation.
45 Left oxygen sensor voltage was over 0.7 volts for 50 seconds when the throttle angle was above 4% during closed loop operation.
51 PROM error. (Means PCM problem)
52 Engine oil temperature was below -31? F after engine had been running for 30 minutes.
53 ECM detected a battery voltage either above 17.1 volts or below 8 volts.
55 ECM detected a lean oxygen sensor voltage for 3 seconds during the power enrichment modes of operation.
62 Engine oil temperature sensor indicated an oil temperature above 284? F after engine had been running for 30 minutes.
63 Right oxygen sensor was open showing a steady voltage between 0.35 and 0.55 volts for 60 seconds after the engine had been running for at least 2 minutes.
64 Right oxygen sensor voltage was below 0.2 volts for 50 seconds of closed loop operation.
65 Right oxygen sensor voltage was above 0.7 volts for 50 seconds of closed loop operation when the throttle angle was above 4%.
66 A/C pressure sensor circuit was either open or shorted showing a voltage below 0.12 volts or above 4.86 volts for 10 seconds.
67 ECM did not detect an A/C system pressure change of more than 9 psi when A/C clutch was engaged.
68 ECM detects voltage on the A/C status line for more than 20 seconds after ECM has disengaged the A/C relay.
69 ECM did not detect any voltage on A/C status line for 20 seconds after ECM had commanded A/C ON.
72 2nd or 3rd gear switch was open for 1.5 seconds when vehicle speed was above 30 MPH with engine speed greater than 5000 RPM and a throttle angle above 70%.
Drifting
Joined: Mar 2012
Posts: 1,492
Likes: 61
From: New Jersey
You can find all that info. right here on the C4 forum in this General Discussion sticky -
https://www.corvetteforum.com/forums...ps-w-pics.html
There is a lot of very good and useful information that members took a great deal of time compiling over the years in the sticky(s) at the top of each section, C4 General Discussion and C4 Tech/Performance. A lot of questions could be answered just by taking a look at them or using the search function in those threads. It's a shame when they aren't being utilized.
https://www.corvetteforum.com/forums...ps-w-pics.html
There is a lot of very good and useful information that members took a great deal of time compiling over the years in the sticky(s) at the top of each section, C4 General Discussion and C4 Tech/Performance. A lot of questions could be answered just by taking a look at them or using the search function in those threads. It's a shame when they aren't being utilized.
