Module 4 is ECM

4.0 ECM waiting for interrogation instructions
4.1 display ECM fault codes
ECM Fault Code List
1984-1991 (L98: VIN 8)
Code Definition
12 No Distributor Reference Pulse (this code is displayed only when engine is not running)
13 Oxygen Sensor Open
14 Coolant Sensor High Temp
15 Coolant sensor Low Temp
21 TPS Voltage High
22 TPS Voltage Low
23 MAT Sensor Temp Low
24 Vehicle Speed Sensor
25 MAT Sensor Temp High
32 EGR System Error
33 MAP Sensor Voltage High
34 MAP Sensor Voltage Low
41 Cylinder Select Error
42 EST System Error
43 ESC System Error
44 Oxygen Sensor (System Lean)
45 Oxygen Sensor (System Rich)
46 VATS Error
51 Mem-Cal Error
52 Engine Oil Temp Sensor Low
53 System Voltage Error
54 Fuel Pump Voltage Low
62 Engine Oil Temp Sensor High

ECM Fault Code List 1990-1993(LT5/ZR-1; VIN J)

Code Definition
13 Left Oxygen Sensor Open
14 Coolant sensor High Temp
15 Coolant Sensor Low Temp
16 DIS Fault Line Error
21 TPS Voltage High
22 TPS Voltage Low
23 MAT Sensor Temp Low
24 Vehicle Speed Sensor
25 MAT Sensor Temp High
31 Cam Sensor Missing or Too Many Pulses
33 MAP Sensor Voltage High
34 MAP Sensor Voltage Low
36 DIS Fault Line/Missing or Extra EST Signal
41 Cylinder Select Error
42 EST System Error
43 ESC System Error
44 Oxygen Sensor (Left Bank Lean)
45 Oxygen Sensor (Right Bank Rich)
46 VATS Error
51 Mem-Cal Error
52 Engine Oil Temp Sensor Low
53 System Voltage Error
54 Fuel Pump Voltage Low
55 Fuel Monitor Lean
56 Port Throttle Vacuum Sensor Low or High
61 Secondary Port Throttle System Error
62 Engine Oil Temp Sensor High
63 Right Oxygen Sensor Circuit Open
64 Right Oxygen Sensor (Right Bank Lean)
65 Right Oxygen Sensor (Right Bank Rich)

1992-1996 (LT-1 VIN P)

DTC Codes 72-99 Pertain to 1994-1996 (LT-1 VIN P)
Code Definition
DTC 11 – Malfunction Indicator Lamp (MIL) Circuit
DTC 13 – Bank 1Left Front) Heated Oxygen} Oxygen Sensor (H02S) #1 Circuit (Open Circuit)
DTC 14 – Engine Coolant Temperature (ECT) Sensor Circuit (Signal Voltage Low,
High Temperature Indicated)
DTC 15 – Engine Coolant Temperature (ECT) Sensor Circuit (Signal Voltage High,
Low Temperature Indicated)
DTC 16 – Distributor Ignition System (Low Resolution Pulse)
DTC 18 – Injector Circuit(s)
DTC 21 – Throttle Position (TP) Sensor Circuit (Signal Voltage High)
DTC 22 – Throttle Position (TP) Sensor Circuit (Signal Voltage Low)
DTC 23 – Intake Air Temperature (IAT) Sensor Circuit (Signal Voltage High,
Low Temperature Indicated)
DTC 24 – Vehicle Speed Sensor (VSS) Circuit
DTC 25 – Intake Air Temperature (IAT) Sensor Circuit (Signal Voltage Low,
High Temperature Indicated)
DTC 26 – Evaporative Emission (EVAP) Canister Purge Solenoid Valve Circuit
DTC 27 – Exhaust Gas Recirculation (EGR) Vacuum Control Signal Solenoid Valve Circuit
DTC 28 – Transmission Range (TA) Pressure Switch Assembly Fault
DTC 29 – Secondary Air Injection (AIR) Pump Circuit
DTC 32 – Exhaust Gas Recirculation (EGR)
DTC 33 – Manifold Absolute Pressure (MAP) Sensor Circuit (Signal Voltage High – Low Vacuum)
DTC 34 – Manifold Absolute Pressure (MAP) Sensor Circuit (Signal Voltage Low – High Vacuum)
DTC 36 – Distributor Ignition System (Faulty High Resolution Pulse or Extra Low Resolution Pulse Detected)
DTC 37 – Brake Switch Stuck “ON
DTC 38 – Brake Switch Stuck “OFF”
DTC 41 – Ignition Control (IC) Circuit (Open Circuit)
DTC 42 – Ignition Control (IC) Circuit (Shorted or Grounded Circuit)
DTC 43 – Knock Sensor (KS) Circuit
DTC 44 – Bank 1 (Left Front) Heated Oxygen Sensor (HO2S) #1 Circuit (Lean Exhaust Indicated)
DTC 45 – Bank 1 (Left Front) Heated Oxygen Sensor (HO2S) #1 Circuit (Rich Exhaust Indicated)
DTC 47 – Knock Sensor (KS) Circuit or Module Missing
DTC 48 – Mass Air Flow (MAF) Sensor Circuit
DTC 50 – System Voltage Low
DTC 51 – EEPROM Programming Error
DTC 52 – Engine Oil Temperature Sensor Circuit (Signal Voltage High, Low Temperature Indicated)
DTC 53 – System Voltage High
DTC 55 – Fuel Lean Monitor
DTC 58 – Transmission Fluid Temperature (TFT) Sensor Circuit Low (High Temperature Indicated)
DTC 59 – Transmission Fluid Temperature (TFT) Sensor Circuit High (Low Temperature Indicated)
DTC 62 – Engine Oil Temperature Sensor Circuit (Signal Voltage Low, High Temperature Indicated)
DTC 63 – Bank 2 (Right Front) Heated Oxygen Sensor (HO2S) #1 Circuit (Open Circuit)
DTC 64 – Bank 2 (Right Front) Heated Oxygen Sensor (HO2S) #1 Circuit (Lean Exhaust Indicated)
DTC 65 – Bank 2 (Right Front) Heated Oxygen Sensor (HO2S) #t Circuit (Rich Exhaust Indicated)
DTC 66 – A/C Refrigerant Pressure Sensor Circuit (Open or Shorted)
DTC 67 – A/C Refrigerant Pressure Sensor Circuit (Pressure Sensor or A/C Clutch Circuit Problem)
DTC 68 – A/C Relay Circuit (Shorted Circuit)
DTC 69 – A/C Clutch Circuit
DTC 70 – A/C Clutch Relay Driver Circuit
DTC 72 – Vehicle Speed Sensor Loss
DTC 73 – Pressure Control Solenoid (PCS) Circuit (Current Error)
DTC 74 – Traction Control System (TCS) Circuit Low
DTC 75 – Transmission System Voltage Low
DTC 77 – Fan Control PCM Terminal “All”
DTC 78 – Fan Control PCM Terminal “Al0”
DTC 79 – Transmission Fluid Over-temp
DTC 81 – Transmission .2-3 Shift Solenoid Circuit
DTC 82 – Transmission 1-2 Shift Solenoid Circuit
DTC 83 – TCC PWM Solenoid Circuit Fault
DTC 84 – 3-2 Control Solenoid Circuit (Automatic Transmission)
DTC 84 – 2nd and 3rd Gear Block-out Relay Control Circuit (Manual Transmission)
DTC 85 – Transmission TCC Stuck “ON”
DTC 90 – Transmission TCC Solenoid Circuit
DTC 91 – One to Four Up shift Lamp (Manual Transmission)
DTC 97 – VSS Output Circuit
DTC 99 – Tach Output Circuit
DTC P0116 – Engine Coolant Temperature (ECT) Circuit Range/Performance Problem
DTC P0117 – Engine Coolant Temperature (ECT) Circuit Low Input
DTC P0118 – Engine Coolant Temperature (ECT) Circuit High Input
DTC P0131 – Bank 1 HO2S #1 Circuit Low Voltage (Lean
DTC P0132 – Bank 1 HO2S #1 Circuit High Voltage (Rich)
DTC P0133 – Bank 1 HO2S #1 Circuit Slow Response
DTC P0134 – Bank 1 HO2S #1 Circuit No Activity Detected
DTC P0135 – Bank 1 HO2S #1 Heater Circuit
DTC P0151 – Bank 2 HO2S #1 Circuit Low Voltage (Lean)
DTC P0152 – Bank 2 HO2S #1 Circuit High Voltage (Rich)
DTC P0153 – Bank 2 HO2S #1 Circuit Slow Response
DTC P0154 – Bank 2 HO2S #1 Circuit No Activity Detected
DTC P0155 – Bank 2 HO2S #1 Heater Circuit Malfunction
DTC P0158 – Bank 2 HO2S #2 Circuit High Voltage
DTC P0160 – Bank 2 HO2S #2 Circuit No Activity Detected
DTC P0161 – Bank 2 HO2S #2 Heater Circuit Malfunction
DTC P0171 – Bank 1 Fuel Trim System Too Lean
DTC P0172 – Bank 1 Fuel Trim System Too Rich (1 of 2)
DTC P0174 – Bank 2 Fuel Trim System Too Lean
DTC P0175 – Bank 2 Fuel Trim System Too Rich (1 of 2)
DTC PO420 – Bank 2 Catalyst System – Low Oxygen Storage Capacity Indicated
DTC P1114 – Engine Coolant Temperature (ECT) Circuit (intermittent Low Input Voltage)
DTC P1115 – Engine Coolant Temperature (ECT) Circuit (Intermittent High Input Voltage)
DTC P1133 – Bank 1 HO2S #1 Circuit Not Enough Switches
DTC P1153 – Bank 2 HO2S #1 Circuit Not Enough Switches
DTC P1158 – Bank 2 HO2S #2 Shifted Rich

1994-1995 LT5/ZR-1 Trouble codes

Due to federal regulations implementing uniform trouble codes throughout the automotive industry, LT5/ZR-1 Corvettes used many of the same 1994 and up codes, except for the codes listed below. (These trouble codes may be in addition to the possible codes above or different meaning)
DTC 31 Camshaft Position Sensor Circuit
DTC 41 Cylinder Select Error (Faulty or Incorrect PROM)
DTC 54 Fuel Pump Circuit (Low Voltage)
DTC 56 Secondary Air Inlet Valve Actuator Vacuum Sensor Circuit (Signal Voltage High “High Vacuum or Signal Voltage Low” (Low Vacuum)
DTC 61 Secondary Air Inlet Valve System
DTC 66 Engine Power Mode Switch Circuit (Signal Voltage High or Signal Voltage Low)

4.7 clear ECM fault codes
Press the TRIP RESET button until 4.0 is displayed in the module number area. Then press the TRIP/ODO button until 4.7 is displayed in the module number area. Press and hold the ENG/MET button until “—“ is displayed. This will clear any ECM codes.
After “—“ is displayed turn the key off, wait ten seconds turn the key back on and check for any ECM codes.

ABS/ASR EBTCM

Press the TRIP RESET button until 9.0 is displayed in the module number area.
Press the TRIP/ODO button until “9.7” is displayed in the module number area. Press and hold the ENG/MET button until “—“ is displayed.
This will clear any ABS/ASR codes. after “—“ is displayed, turn the key off, wait ten seconds, turn the key back on and check for any ABS/ASR codes.