Actually felt the ah applying the brakes several times today when it reset codes on the way to work. The battery tested ok so that eliminates the first step. Going by Grainger tomorrow to get a can of Corosion X. Will start cleaning the grounds/connectors Saturday. This is the first time the car has had any issues. Hope it's not a picture of horrors to come.

Got a friend that's replacing his steering position sensor on Sunday. Going to give him a hand just in case I end up having to replace mine.

 

I had a 98 and now a 2000. Both had the sender issue and both respond well to the use of the Techron fuel additive. I don't know what's so damn special about a small variable resistor that makes it cost so much but I really think Corvette owners are being deliberately raped by Chevrolet. They won't do the right thing and replace the bad senders, or the seat tracks, or the harmonic balancers, or the A/C controllers and on and on. They haven't even redesigned the known bad designed parts to correct common issues as they discover them. They just keep producing cars with known bad parts.

 

Good info Bill. Thank you.

 

No problem!

Bc

 

Decided to have another load test done on the battery because the guy at the first store was pretty much a flake. Last night the load test showed that the battery was not holding a charge so replaced it with a new Optima red top. Had to drive about 30 miles to get home. No codes and I thought that fixed it until I got about a mile from the house and the left rear brake pulsed and service active handling was back with C1281.

Picked up the Corrosion X I ordered at Grainger so I'll start cleaning the grounds/connectors this morning and see if that fixes it.

If that doesn't do it I'm going to get a new alignment done as the steering wheel is canted to the left slightly from the last alignment. That was done two years ago and no problems since then. if I had known at the time how critical that the wheel be exactly straight I would have made them correct it then.

Really hoping I don't have to replace the SPS.

 

Just finished pulling apart 101, 102 and 104. Could not get the nut off of 103 and definately didn't want to break that stud so I sprayed it liberally with Corrosion X. There was some minor corrosion on 101 & 102 (nothing near the pics on page 1) that I cleaned up and treated with Corrosion X. 104 just had very minor corrosion.

Took it for a test drive and got c1286 and c1287 again within 2 miles.

I'm kinda stumped at this point. Several posts mentioned getting a good alignment and checking the voltage on the SPS. The steering column has never been uncoupled so I don't see how the voltage could be wrong unless the sensor has gone bad. I'm unclear on how to check the voltage myself. Any help on a next step is appreciated.

Don't want to take it to my local stealership as they are clueless on C5's.

 

DO you have ACTIVE HANDLING???????

BC

 

I believe the active handling is working but when it sets the codes the active handling light comes on.

 

The AH TC, and steering wheel position system components DO NOT incorporate any CHASSIS Grounds. They all use discrete circuit grounds.

Thats not to say that the chassis grounds should be ignored. They provide the return path for the 12 VDC voltage that powers the modules that generate the signals that your having issues with.

Now that I know that you have AH (RPO JL4) I can provide you the CORRECT information:

DTC C1287 Steering Sensor Rate Malfunction DTC C1287 (RPO JL4)

Circuit Description
The EBTCM uses three inputs from the Steering Wheel Position sensor:

Phase A digital input
Phase B digital input
Analog input
This information is used to calculate three things:

The front wheels position when centered.
The front wheels position when turning.
The vehicles lateral acceleration.
The EBTCM runs a centering routine when the vehicle speed goes above 10 Km/h (6 mph). When the vehicle reaches 10 Km/h (6 mph), the EBTCM monitors the Steering Wheel Position Sensor inputs (Phase A, Phase B and Analog voltage) to see if the steering wheel is moving. If the steering wheel is not moving for a set period of time, then the EBTCM assumes the vehicle is going in a straight line. At this point, the EBTCM looks at the analog voltage signal and reads the voltage. This voltage, normally around 2.5V, is then considered the center position and the digital degrees also become zero at the same time. This centering routine is necessary to compensate for wear in the steering and suspension. Wear in the steering and suspension can result in a change in the relationship between the steering wheel and the front wheels. By running the centering routine the EBTCM can compensate for these changes by changing the digital and analog center position.

The EBTCM uses the digital input (Phase A and Phase B) from the Steering Wheel Position Sensor to calculate the direction the driver of the vehicle is trying to steer during an ABS and Active Handling event. This information is also used to calculate the vehicles lateral acceleration for Magnasteer®2.

Conditions for Setting the DTC
DTC C1287 can be set any time ignition is present. A fault exists if the steer rate (speed that the steering wheel appears to be turning) exceeds the limits set by the EBTCM.
DTC C1287 will set if the analog degrees differs from the digital degrees by more than 25 degrees for 5 seconds when the vehicle is not in a Active Handling event, or 1 second if the vehicle is in an Active Handling event.
Action Taken When the DTC Sets
ABS and TCS remain enabled, Active Handling™ is disabled.

Indicators that turn on: Car Icon (TCS indicator
Messages displayed on the DIC: Service Active HNDLG Service Vehicle Soon
Conditions for Clearing the DTC
Condition for DTC is no longer present and scan tool clear DTC function is used.
Fifty ignition cycles have passed with no DTCs detected.
Diagnostic Aids
It is very important that a thorough inspection of the wiring and connectors be performed. Failure to carefully and fully inspect wiring and connectors may result in misdiagnosis, causing part replacement with reappearance of the malfunction. Check connector C102 RH side rear of engine compart for water intrusion or missing plugs, and that the connector is oriented horizontal to prevent water intrusion.

Test Description
The numbers below refer to the step numbers on the diagnostic table.

Checks for normal state change of Phase A and Phase B when turning left.

Checks for normal state change of Phase A and Phase B when turning right.

DTC C1287 Steering Sensor Rate Malfunction Step
Action
Value(s)
Yes
No

1
Was the Diagnostic System Check performed?
--
Go to Step 2
Go to Diagnostic System Check - ABS

2
Is this vehicle equipped with Active Handling (RPO JL4)?
--
Go to Step 3
Go to DTC C1287 Steering Sensor Rate Malfunction

3
Start the engine.
Ensure the front wheels are straight.
Turn the ignition OFF.
Restart the engine.
Slowly rotate the steering wheel to the left while monitoring Phase A and Phase B of the Steering Wheel Position Sensor using a scan tool.
Did phase A and phase B change states uniformly as the steering wheel was rotated?
--
Go to Step 4
Go to Step 5

4
Slowly rotate the steering wheel to the right while monitoring phase A and phase B of the Steering Wheel Position Sensor using a scan tool.

Did phase A and phase B change states uniformly as the steering wheel was rotated?
--
Go to Step 6
Go to Step 5

5
Replace the Steering Wheel Position Sensor. Refer to Steering Shaft, Lower Bearing, and Jacket - Disassemble - Off Vehicle in Steering Wheel and Column.

Is the replacement complete?
--
Go to Step 6
--

6
Read the diagnostic aids and conditions for setting the DTC.
Cycle the ignition switch from the OFF to ON position.
Start the engine and rotate the steering wheel from left to right while monitoring a scan tool for ABS/TCS/Active Handling DTC(s).
Did DTC C1287 set as a current DTC?
--
Go to Step 7
Go to Diagnostic System Check - ABS

7
Replace the EBTCM. Refer to Electronic Brake Control Module (EBCM) Replacement .

Is the replacement complete?
--
Go to Diagnostic System Check - ABS
--



--------------------------------------------------------------------------------
Document ID# 379435
1999 Chevrolet/Geo Corvette



DTC C1286 Steering/Lateral Accelerometer Sensor Bias Malfunction DTC C1286 (RPO JL4)




Circuit Description
Steer angle centering is the process by which the EBTCM calibrates the steering sensor output so that it reads zero when the steering wheel is centered. The initial steering wheel center position is calculated after driving 10 Km/h (6 mph) for more than 10 seconds in a straight line on a fairly level surface. The EBTCM uses the Yaw Rate Sensor, Lateral Accelerometer and Wheel Speed Sensors to tell if the vehicle is moving in a straight line. This centering routine is necessary to compensate for wear in the steering and suspension. Wear in the steering and suspension can result in a change in the relationship between the steering wheel and the front wheels. By running the centering routine the EBTCM can compensate for these changes by changing the digital and analog center position.

Conditions for Setting the DTC
DTC C1286 can be set after the centering routines completion if the bias value is plus or minus 40 degrees from the previous bias value.
DTC C1286 can also be set at start up if the bias value was out of range on the last ignition cycle.
Action Taken When the DTC Sets
ABS and TCS remain enabled, Active Handling™ is disabled.

Indicators that turn on: Car Icon (TCS indicator
Messages displayed on the DIC: Service Active HNDLG Service Vehicle Soon
Conditions for Clearing the DTC
Condition for DTC is no longer present and scan tool clear DTC function is used.
Fifty ignition cycles have passed with no DTCs detected.
Diagnostic Aids
It is very important to check the vehicle for proper alignment. The car should not pull in either direction while driving straight on a flat surface.
It is very important to find out from the driver when the code was set, (when the SERVICE ACTIVE HNDLG message was activated). This information may help to duplicate the failure.
It is very important that a thorough inspection of the wiring and connectors be performed. Failure to carefully inspect wiring and connectors may result in misdiagnosis, causing part replacement with reappearance of the malfunction. Check connector C102 RH side rear of engine compart for water intrusion or missing plugs, and that the connector is oriented horizontal to prevent water intrusion.
An intermittent malfunction is most likely caused by a poor connection, rubbed through wire insulation, or a wire that is broken inside the insulation. Refer to Testing for Electrical Intermittents in Wiring Systems.
Test Description
The numbers below refer to the step numbers on the diagnostic table.

Recenters the Steering Wheel Position Sensor.

DTC C1286 Strg/Lateral Accel Sensor Bias Malf Step
Action
Value(s)
Yes
No

1
Was the Diagnostic System Check performed?
--
Go to Step 2
Go to Diagnostic System Check - ABS

2
Is this vehicle equipped with Active Handling (RPO JL4)?
--
Go to Step 3
Go to DTC C1286 Steering Sensor Bias Malfunction

3
Using a scan tool, read ABS/TCS/Active handling DTC(s).

Is DTC C1282 or DTC C1284 set as a current DTC?
--
Go to Applicable DTC Table. Refer to Diagnostic Trouble Code (DTC) List
Go to Step 4

4
Point the front wheels straight ahead.
Using a scan tool, check the Steering Wheel Position Sensor Analog voltage.
Is the voltage within the range specified within the value(s) column?
2-3 V
Go to Step 5
Go to Step 11

5
Using a scan tool, perform the Steering Wheel Position Sensor Test. Refer to Scan Tool Diagnostics .

Are the analog and digital displays on the scan tool within plus or minus 5 degrees of each other at the center (zero) position?
--
Go to Step 6
Go to Step 12

6
Perform the Diagnostic Test Drive while monitoring the Yaw Rate Sensor output in degrees/seconds on a scan tool. Refer to Diagnostic System Check - ABS .

Are the degrees/second displayed on the scan tool within the range specified in the value(s) column?
0-5 degrees/second
Go to Step 8
Go to Step 7

7
Replace the Yaw Rate Sensor. Refer to Yaw Rate Sensor Replacement .

Is the replacement complete?
--
Go to Step 14
--

8
With the ignition switch in the ON position and the engine off, monitor the Lateral Accelerometer output in voltage using a scan tool.

Is the voltage displayed on the scan tool within the range specified in the value(s) column?
2.3-2.7V
Go to Step 14
Go to Step 9

9
Replace the Lateral Accelerometer. Refer to Lateral Accelerometer Replacement

Is the replacement complete?
--
Go to Step 14
--

10
Replace the EBTCM. Refer to Electronic Brake Control Module (EBCM) Replacement .

Is the repair complete?
--
Go to Diagnostic System Check - ABS
--

11
Turn the ignition switch to the OFF position.
Disable the Supplemental Inflatable Restraint (SIR). Refer to Disabling the SIR System in SIR.
Remove the Inflatable Restraint Wheel Module Coil. Refer to Inflatable Restraint Steering Wheel Module Coil Replacement in Steering Wheel and Column.
Remove the Intermediate Shaft. Refer to Intermediate Steering Shaft Replacement in Steering Wheel and Column.
Turn the ignition switch to the ON position, engine off.
Using a scan tool monitor the Steering Wheel Position Sensors analog voltage as you rotate the steering column shaft.
Turn the steering column shaft until the analog voltage is close to 2.5 volts.
Does the analog voltage move to or close to 2.5 volts?
--
Go to Step 13
Go to Step 12

12
Replace the Steering Wheel Position Sensor. Refer to Steering Shaft, Lower Bearing, and Jacket - Disassemble - Off Vehicle in Steering Wheel and Column.

Is the replacement complete?
--
Go to Step 14
--

13
Leave the steering column shaft centered at 2.5 volts.
Turn the ignition switch to the OFF position.
Install the Intermediate Shaft. Refer to Intermediate Steering Shaft Replacement in Steering Wheel and Column.
Install the Inflatable Restraint Wheel Module Coil. Refer to Inflatable Restraint Steering Wheel Module Coil Replacement in Steering Wheel and Column.
Enable the SIR. Refer to Enabling the SIR System in SIR.
Is the repair complete?
--
Go to Step 14
--

14
Turn the ignition switch to the ON position, engine off.
Using a scan tool clear DTC C1286.
Drive vehicle above 30 Km/h (18 mph) for several minutes.
Using a scan tool check for DTC C1286.
Did DTC C1286 set as a current DTC?
--
Go to Step 10
Go to Diagnostic System Check - ABS



--------------------------------------------------------------------------------
Document ID# 379431
1999 Chevrolet/Geo Corvette



Take a read on the above two diagnostic guides and see what you think. How is your steering wheel positioned when your going straight down a level straight road. Should be dead nuts centered.

BC

 

When the car was aligned 2 years ago (10k miles) the steering wheel was set very slightly canted to the left. Didn't understand at the time how critical the wheel being exactly straight was. Everything seems to point to the swps having gone bad. Spent a lot of time researching the c1286 and c1287 codes the last few days. I checked the sensor plug this afternoon and it was firmly plugged in.

Still don't know if I should try an alignment first before I order a new swps ($251) from Gene Culley. Seems to be a fairly high failure rate on the sensor.

 

There's a lot to read in this read at 50 plus pages, so forgive me if this has been asked and answered, but is there a specific ground that would cause the engine to sporadically miss two or three times and then shut down giving the DIC error of "charging system fault". I was able to disengage the clutch, then drop it, and the motor fired right back up.

Or any other suggestions...

Thanks

Only codes were
B2282H
B2283H
B2284H
B2285H
U1064H

 

Without knowing a lot more info,,, it sounds like defective loose or dirty battery connection or an issue on the starter solenoid connection. Give that a shot first The battery terminal torque is 11 ft/lbs.

BC

 

I Just replaced my alternator due to intermitant performance, It is much better now, but I wonder if the ground may not be the issue, The one near the coolant tank is obviously corroded on the nut.

Can you provide clear instruction on how to unplug these conectors, I have pulled and pryed, but I supect there is a easier way.

 

I found the easier way, If you unbolt the conector from the car, you can see that there is a clip on the bottom as well as the top. If you push them both in it will unplug. You just cant see the bottom clip unless you remove the clip from the car.


I will post if this solves my problem, the ongoing issue that I am having is the active handling comming on during normal driving, this cause a small but noticable wiggle in the car when the active handling hit one on the brakes.

Yhe only other code I have, both H and C, is the Magnasteer manfunction (c1241)

 

I am really curios as to what you found. i have the exact same issue with my car right now. It started Monday and is driving me nuts.

Update: I pulled the alternator and had it tested. It failed.... Installed a new alternater this morning and everything works as it should.

 

Bill great info I just picked up my first vette. It's used and kind of a fixer up. Thanks for the info

 

Problems came back today....key fob didn't work, so I pressed both buttons to set it and it still wouldn't work.
So I unlock the car, and it has power when I put the key in, but turn it and nothing....pulled it out, and tried again and it started right up.
Then all the small gauges went dead, reduced power, AC turned off, power windows died, service TPMS, service traction control, etc all lit up in the DIC!!

So my left window still worked, but the right was dead. So I pulled over, and left the car idling and got out and opened the passenger door and pressed the window up and down button while wiggling the corrugated rubber boot between the door and car frame. The window started to work.
The wiggle that made it work was closer to the door end of it, so I guess I am going to pull the passenger door panel off on the weekend and check for a loose connection.

Also note that when the right power window switch was dead, so was the right side power lock....both were dead when you used the left side master switch too.

 

Hi Bill,

It seems you are the go to guy for electrical gremlins in C5's. My 2003 EB Z06 has 65k miles and is bone stock other than a Vararam intake. The car has never given me any major problems up until now...

I consider myself mechanically inclined, however on the electrical side I am a bit in the dark.

Over the past few months I've been throwing P0357 - "Ignition coil #7 circuit" I have done the typical things to diagnose the problem however the solution still evades me. I should also mention that this code is intermittent and can not be reproduced on command. Over the past few weeks it seems to be occurring in greater frequency. There is no noticeable difference in performance with the code active or when everything is temporarily OK. I have also noticed a slight "pinging" sound from under the dash (only occasionally at high WOT RPM's), but I'm willing to bet this is my throw out bearing telling me to replace it. I am mentioning this because it could very well be a ping from a bad coil circuit BUT if this were the case, why would I not get a misfire or knock code??

I have done the following to troubleshoot thus far:

-Swap Coil banks (code did not follow, still P0357)
-Swap plugs and wires from #3 and #7 (code did not follow, still P0357)
-New plugs and wires (old plugs looked OK. #7 was slightly darker than others)
-I have checked coil harnesses/pins for spread female ends and chaffing/rubbing.

It was mentioned here that the harness might rub on the fuel rail. My harness does show a small amount of rubbing, however was not able to locate a tear or break in the harness. Wiggling the harness does not replicate the code nor help my situation.

In doing these things I'm lead to believe that the problem is further up in the circuit, either a bad harness or PCM.

I was able to find this post that explains how to troubleshoot my code, however its in spanglish to me!! Can you or someone put this into laymens terms? I have a cheap DMM that I would love to use to check the continuity of the harness and the PCM, but have no clue where to start or what pins/locations to check.

I apologize if I omitted any important information questions/advise welcome!

I really don't want to take this into the stealership to fix so I'm at the forums mercy!

Thanks!!

 

Say what? I want my click back.

Charlie

 

Hi Bill,
I skimmed through the 57 pages and wanted your thoughts on my problem as it did not appear to be stated yet.

We have been having the intermittent problem with the passenger window, works, doesn't work, works, so I will have to try the wire issue between the door next time.

Lately, when I turn the headlights on, they light up, but do not raise. I then turn the switch to off, and then back on and almost always, they will raise on the second try. This is very puzzling. Car has 68k miles.

Also, during the day with the lights off, I have noticed that the blue MPH display is bright then fades to dim, then gets bright again. Tonight, sitting at idle in a parking lot and while driving, ALL of the lights, dash, interior, headlights flicker - go dim and then bright. (they dim for about a second or two, stay bright for 30 to 45 seconds). I might guess that the voltage regulator is going bad in the alternator, but I am not getting any of the strange DTC codes that most of this post talks about with the ground problems. We live outside chicago and the corvette is parked in the garage all winter. It has not seen snow.

Just hoping for a little insight before I jumped at the grounds or replaced the alternator. Car has had a replacement battery, and I use a battery tender during the winter when the car is in storage.

On a side note, the fuel sender issue you describe has been an intermittent problem and the key FOB does not work at all. Thanks.