_twisted_

Car sat for about 10 days, warmed up the car loaded up with parts etc parked it. Came out 1/2 hr later barely started, fan came right on and wouldn't run on its own, then SES lit up.These 2 codes showed up

Code #15 Coolant Sensor High
Code #43: Electronic Spark Control.

Drove it a few miles, then topped off the tank, restart no SES lit runs good.

Next morning, code 43 back again "safe to drive", drove to the garage

Was doing a t stat change so I replaced the sensor while it was drained, no more #15

43 still present, checking the scanner one minute I would have advance then not.

Shut the car off, clear codes, turn key to on and the damn fan is running again but no #15, started it and with in 30 sec the #43
came back, put car in rev and it barely stayed running.

Made it back home, sat over night.
Started but #43 still there and the fan was running before starting cold
ran without assistance, topped of tank, restart no more SES lit

Let it sit for a couple hours, restarted running good. I put about 15 miles on it, picked up dinner came out started was fine
was stopping at the merge onto the highway , as I rolled down the slight decline to get onto the highway she stutterd and almost died but recovered then through the #43 again.

Where do I start? Electrical or check my fuel.

I changed the fuel filt when I did the coolant.

Any help is appreciated.

skateparkdave

Code 43 is knock sensor.

42 is EST.

May be time for a new knock sensor if wireing is all connected and in order.

_twisted_

Code #42: Electronic Spark Timing.
Code #43: Electronic Spark Control.

Yeah that added to the confusion, cus I was focusing on the spark module, why don't they just say knock sensor

ChevyTech

A little more info on code 43s

Each time the car is started and certain criteria is met (coolant temp, MAP reading, engine RPM), a self test of the knock senor circuit is run. Only one test is run for each start of the vehicle. The ECM adds spark advance while anticipating a knock signal. If not knock signal is detected during the test a code 43 will be set.

_twisted_

Does this test take 15-30 seconds to complete or is it variable?

skateparkdave

What manual do you have that calls the knock sensor ESC?? Just curious. I bet replacing your knock sensor will remedy your trouble.

Here's a list of C4 codes and remedies I copied from a great website some time ago that is no longer up and running, but you may find this useful in the future.

Code Circuit or Sensor
13 Oxygen Sensor Circuit
14 Coolant Sensor Circuit (High)
15 Coolant Sensor Circuit (Low)
16 Ignition Pblms (Used on 1992-1996 models only)
21 Throttle Position Sensor (TPS) (High)
22 Throttle Position Sensor (TPS) (Low)
23 Intake Air Temperature (Low)
24 Vehicle Speed Sensor (VSS)
25 Intake Air Temperature (High)
26 Quad Driver Module Number 1
27 Quad Driver Module Number 2
28 Quad Driver Module Number 3
32 Exhaust Gas Recirculation Circuit
33 Mass Air Flow Sensor Circuit (1985-1990)
33 Manifold Absolute Pressure High (1984)
34 Mass Air Flow Circuit (1985-1990)
34 Manifold Absolute Pressure Low (1984)
35 Idle Air Control Circuit (IAC)
36 Mass Air Flow Burn Off Circuit
41 Cylinder Select Error Circuit (1985-1991)
42 Electronic Spark Timing Circuit (EST)
43 Knock Sensor Circuit
44 Lean Exhaust Present
45 Rich Exhaust Present
46 VATS Anti Theft Circuit Fault
51 PROM/EEPROM Error
52 Oil Temperature Circuit (Low Temperature)
53 System Charging Voltage High or Low
54 Fuel Pump Circuit (Low Voltage)
55 Engine Running Lean
62 Oil Temperature Circuit (High Temperature)
63 Oxygen Sensor Circuit (Open)
64 Oxygen Sensor Circuit (Lean Exhaust)
65 Oxygen Sensor Circuit (Rich Exhaust)
66 Air Conditioner Pressure Limit Exceeded
67 Air Conditioner Pressure Limit Exceeded
68 Air Conditioner Relay Fault
69 Air Conditioner Clutch Fault
72 Gear Selector Switch Fault (Start Lockout)

Possible Failures Associated with ECM Codes (From most likely to least likely)

13 Check wiring and connectors. Bad Sensor
14 Check wiring, connectors, thermostat. Monitor actual engine temperature. If within limits, and wiring/connector is OK, change thermostat and/or sensor.
15 See above, particularly thermostat
16 Direct Ignition (DI) Fault
21 Sticking or Misadjusted TPS. Also check wiring/connectors. Adjust/replace TPS.
22 Sticking or Misadjusted TPS. Also check wiring/connectors. Adjust/replace TPS.
23 Measure sensor resistance with Digital Ohm meter. Must not be 0 ohms or infinite ohms. Replace if it shows one of these readings. Check wiring/connector of sensor. If OK, replace sensor.
24 Only valid if vehicle moving. Check connections at ECM Check TPS setting. Possible ECM failure.
25 Measure sensor resistance with Digital Ohm meter. Must not be 0 ohms or infinite ohms. Replace if it shows one of these readings. Check wiring.connector of sensor OK.
26 Check EGR, Canister Purge and AIR pump relays with a digital Ohm meter. A resistance of less than 18 ohms indicates a bad relay. If OK, potential ECM failure.
27 Potential ECM or on a manual transmission car, potential upshift relay problem. Check relay, replace if less than 18 Ohms using a digital Ohm Meter.
28 Air conditioning Clutch relay and/or cooling fan relays. Check with digital Ohm meter, replace if less than 18 Ohms. If relays OK, potential ECM failure.
32 The most common cause of this code is a bad or intermittent EGR switch which is located on the EGR pipe between the exhaust manifold and the intake manifold. Replace this switch first when you get this code. Next, check electrical connections at EGR valve solenoid and then the ECM. Check all vacuum lines for leaks especially around the EGR valve. Possible ECM failure.
33 (1985-1990) Inspect intake system for leaks, Inspect for vacuum leaks, Check MAF connector and wiring, Check MAF for open using digital Ohm meter. Possible ECM failure.
33 (1984) Check vacuum hoses. Check wiring to sensor. Change sensor. Check connections at ECM.
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 IAC 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.

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ChevyTech

I don't know how long it takes to complete. 15-30 sounds reasonable to me.

I'll do a little digging, but I don't remember seeing this type of criteria in print.

ChevyTech

ChevyTech

I don't know how long it takes to complete. 15-30 sounds reasonable to me.

I'll do a little digging, but I don't remember seeing this type of criteria in print.

_twisted_

I got them from CAC http://www.corvetteactioncenter.com/....php?qstId=135
here
Also that ESC show on the snapon scanner, when I pulled the plug on the "what I thought was the esc" it threw a code 42.
I also looked in the helms, and unless I was delirious, I swore it pointed me to the module that threw the 42.

skateparkdave

Ok Im confused now. Did it throw a 43, as in thread title? Or a 42?

42 is EST circuit
43 is what you said in thread title that you had, and thats a knock sensor code.

I went here http://www.corvetteactioncenter.com/....php?qstId=135 and saw what you were talking about. Thats the first I've ever seen the knock sensor refered to as Electronis Spark Control. All of my books say 43 is knock sensor. Hmmmm, perhaps it's a different term for the same thing. Maybe someone else will chime in and clarify this.

_twisted_

Sorry for the confusion it threw a 43