So I'm driving home today and my car started freaking out, the ASR, Service ASR, and Service Engine Soon lights all came on at the same time. After that my car would no longer shift gears properly. I have an automatic. I got the following trouble codes from it:
H22
H64
H67
H77
H78

After reading up, it looks like I have some explanations for most of them except the H78 which isn't listed in the Chiltons.

The H22 is : Throttle Position Sensor Circuit - Signal Voltage Low.

Could this one code cause all of the others?

I just installed the 383 and all of the items in my sig below this past weekend. I have put about 350 miles on the new motor since Tuesday without any problems whatsoever and then this happens all of the sudden.

Any help would be appreciated.

Tim

 

H78 is Fan control PCM terminal A10. Possible relay?

 

Hmmm - I have my electric water pump hooked up to one of the fan relays for the switched ignition power. I wonder if it's trying to draw too much when the fans are running....

 

I believe this is the correct list for corvette's (it is for LT1 f-bodies, and I am 99% sure it is the same)


DTC 11 - Malfunction Indicator Lamp (MIL) Circuit
DTC 13 - Bank I (Left) Heated Oxygen Sensor (HO2S) Circuit (Open Circuit)
DTC 14 - Engine Coolant Temperature (ECT) Sensor Circuit ( Voltage Low, High Temp)
DTC 15 - Engine Coolant Temperature (ECT) Sensor Circuit ( Voltage High, Low Temp)
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 ( Voltage High, Low Temp)
DTC 24 - Vehicle Speed Sensor (VSS) Circuit
DTC 25 - Intake Air Temperature (IAT) Sensor Circuit ( Voltage Low, High Temp)
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 (TR) 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 ( Voltage High - Low Vacuum)
DTC 34 - Manifold Absolute Pressure (MAP) Sensor Circuit ( Voltage Low - High Vacuum)
DTC 36 - Distributor Ignition System (Faulty High Res. or Extra Low Res. 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) Heated Oxygen Sensor (HO2S) Circuit (Lean Exhaust Indicated)
DTC 45 - Bank 1 (Left) Heated Oxygen.Sensor (HO2S) Circuit (Rich Exhaust Indicated)
DTC 46 - PASS-Key Circuit
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 53 - System Voltage High
DTC 55 - Fuel Lean Monitor
DTC 58 - Transmission Fluid Temperature (TFT) Sensor Circuit Low (High Temp )
DTC 59 - Transmission Fluid Temperature (Low Temperature Indicated)
DTC 61 - A/C System Performance
DTC 63 - Bank 2 (Right) Heated Oxygen Sensor (HO2S) Circuit (Open Circuit)
DTC 64 - Bank 2 (Right) Heated Oxygen Sensor (HO2S) Circuit (Lean Exhaust Indicated)
DTC 65 - Bank 2 (Right) Heated Oxygen Sensor (HO2S) 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 Activity)
DTC 68 - A/C Relay Circuit (Shorted Circuit)
DTC 69 - A/C Clutch Circuit
DTC 70 - A/C Clutch Relay Driver Circuit
DTC 71 - A/C Evaporator Temperature Sensor Circuit
DTC 72 - Vehicle Speed Sensor Loss
DTC 73 - Pressure Control Solenoid (PCS) Circuit (Current Error)
DTC 74 - Traction Control System(TCS)CircuitLow
DTC 75 - Transmission System Voltage Low
DTC 77 - Cooling Fan Relay Control Circuit
DTC 78 - Fan control PCM terminal A10
DTC 79 - Transmission Fluid Overtemp
DTC 80 - Transmission Component slipping
DTC 81 - Transmission 2- 3 Shift Solenoid Circuit
DTC 82 - Transmission 1-2 Shift Solenoid Circuit
DTC 83 - Reverse Inhibit System (Manual Transmission) <<<<<<<<<select>>>>>>
DTC 83 - TCC/PWM (Auto Trans)
DTC 84 - Automatic Transmission 3-2 Control Solenoid Circuit <<<select>>>>>>
DTC 84 - Skip Shift Solenoid Circuit (Manual Transmission Only)
DTC 85 - Transmission TCC Stuck "ON
DTC 90 - Transmission TCC Solenoid Circuit
DTC 91 - Skip Shift Lamp Circuit
DTC 97 - VSS Output Circuit
DTC 99 - Tach Output Circuit


It sounds to me like you have an electric problem somewhere (sure that was a bunch of help ). In cases like that the first thing I would due is double check all the grounds and the grounding straps. Check any new electrical connections you made also. I would run a separate relay for your electric waterpump also - you can use any ign source to trigger it, but power it from +12v on the battery.
Now double check all your grounds .

Re: the TPS issue - what *is* your tps at idle/WOT (car doesn't have to be running to check this, just key on)? Is your TPS sensor possibly loose, and check to make sure the shaft isn't spinning inside the sensor.