| Code |
Code
Possible Fault (From most likely to least likely) |
| 34 |
(1985-1990) Clean the
throttle body. Check MAF connections. Replace MAF relay.
Replace MAF Sensor. Possible ECM failure. |
| 34 |
(1984) Check Vacuum hoses
associated with MAP sensor. Check wiring and connections,
particularly at ECM. Replace the sensor. Possible ECM
failure. |
| 35 |
Check fuel pressure, injectors,
leaking throttle body. Change the Idle Air Control valve.
|
| 36 |
Check connections at MAF,
MAF relay and MAF Burn off relay. Check resistance of
MAF relay and MAF burnoff relay with digital Ohm meter.
replace if less than 18 Ohms. Possible ECM failure. |
| 41 |
Check wiring at ECM. Possible
PROM failure, or incorrectly seated PROM. Reseat PROM.
Possible ECM failure. |
| 42 |
Check wiring at ignition
module. Replace ignition module. Possible ECM failure. |
| 43 |
Check ECM wiring. Replace
knock sensor |
| 44 |
Check wiring.connectors
at Oxygen sensor. Check fuel pressure. Replace Oxygen
sensor. |
| 45 |
Check evaporative charcoal
canister for smell of fuel (which normally comes from
filling fuel tank to full). check fuel pressure regulator.
Possible leaking fuel injector or sticking/bad EGR valve.
Possible bad Oxygen sensor. |
| 46 |
With negative battery
lead disconnected and using high pressure, non residue
contact spray cleaner, spray into area where ignition
key inserts followed by inserting and removing key several
times. Check for open / short on harness from steering
column VATS ignition key to ECM. Possible defective anti-theft
module. |
| 51 |
Faulty or incorrect PROM
in the ECM. Change PROM with correct version for automobile.
|
| 52 |
Check connections at the
oil temperature switch. If OK, replace switch. |
| 53 |
If voltage is more than
17.1 or less than 10 volts, this code will be set. Check
battery leads, alternator drive belt for tightness and
have electrical shop check alternator output. Voltage
with engine off should be 12 volts. Voltage with engine
running should be 14-15 volts. Use digital volt meter
for checks and measure at the battery terminals. |
| 54 |
Using digital Ohm meter,
check fuel pump circuits for shorts or opens. |
| 55 |
This code is set when
there is not enough fuel when accelerating. A possible
fuel pump failure or insufficient fuel pressure due to
a fuel line restriction is indicated. |
| 62 |
Check wiring associated
with Oil temperature switch. Replace switch. |
| 63 |
Check wiring and connections
to Oxygen sensor. |
| 64 |
Check wiring and connections
from Oxygen sensor to ECM. Check ECM ground terminal and
battery ground. Check fuel pressure and fuel pump. Replace
Oxygen sensor if all of above OK. |
| 65 |
Check evaporative charcoal
canister for fuel fumes. Replace if contaminated. Check
oil for presence of fuel. Check fuel pressure regulator,
fuel pump, check for leaking injectors, Check for stuck/defective
EGR valve, Replace Oxygen sensor if all above OK. |
| The C4 Corvette uses several
computers---more in the later models than the early years---
and each has it's own set of trouble codes. The Anti-Lock
Brake System (ABS) , Automatic Slip Regulation (ASR),
Selective Ride System (SRS) as well as the Air Conditioner
Controller, the Air Bag's computer system (called the
DERM module) plus the Central Control Module (CCM) on
1990 and later C4s, all have their own computers and their
own set of possible trouble codes. Some can be recovered
without a scan tool, some cannot. You will need a service
manual for your year C4 to discover the procedure to gain
access to those codes. |
