Greetings,
So yesterday on the way home from work I got a Check Engine light. Upon downloading the codes, I got some codes that I’ve not seen before in the Corvette Forum or in my car and I hope someone can help me. I intend on cleaning all my grounds.
Here are the codes that are new to me;
C1241 Magna Steer Circuit Malfunction
C1281 Steering Sensor Uncorrelated Malfunction
Can anyone help me with details on this circuit? I intend on cleaning the grounds first but can anyone identify the grounding points and the connections that I can check.
After I parked my car, I cleared out all the current and History codes. I restarted the car and rechecked the codes once again. The C1241 code is came up again. The grounds have never been cleaned and the Steering system has never been worked on. I don’t know if that makes a difference but the car is also stock.

Thanks

 

ttt

 

So I cleaned some of the grounds on my car that I was able to get to. I've cleaned G101, G102, G103, and G104. Most of the code cleared but the C1241 Magna Steer Circuit Malifunction and a new code poped up P0410 Air System.
Under Bill's advise, I've looked for any Steering related connector and was able to see one connector, I disconnected, cleaned and reconnected. Problem still exists. Is any one that has a service manual on these two section that can give me a hand?

Thanks

 

DTC C1241
Circuit Description
The variable effort steering (VES) system uses the electronic brake control module (EBCM) to control current to a bi-directional electromagnetic rotary actuator. The EBCM commands current from negative 2 amps to positive 3 amps to the actuator. At low speeds, a negative current is commanded, which assists steering. At medium speeds, no current is commanded and steering is assisted by hydraulics only. At high speeds, a positive current is commanded, which creates steering resistance.

Conditions for running the DTC
Ignition voltage between 10.5 and 17 volts
Off state test - Initial ignition ON, no engine rpm or vehicle speed present.
On state test - If off state test passes, engine rpm and vehicle speed present.
Conditions for Setting the DTC
An open, short to ground, or short to voltage in the VES actuator or the circuits to the actuator.

Action Taken When the DTC Sets
A DTC C1241 is stored in memory.
The DIC may display the SERVICE STEERING SYS warning message.
The VES system is disabled.
Conditions for Clearing the DTC
A current DTC will clear when malfunction is no longer present.
A history DTC will clear after 100 consecutive ignition cycles with no malfunction present.
Using the scan tool.
Diagnostic Aids
The vehicle needs to be driven to view full commanded and feedback current ranges on the scan tool.

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

Tests if the Commanded and Feedback Current parameters are at the specified value in there active state.

Tests if the resistance of the VES actuator is in the specified range.

Tests the high effort control circuit for an open or short to voltage.

Tests the low effort control circuit for a short to ground.

Tests for poor connections at the VES actuator harness connector.

Perform the setup procedure after EBCM replacement.

Step
Action
Value(s)
Yes
No

Schematic Reference: Steering Controls Schematics

Connector End View Reference: Steering Controls Connector End Views

1
Did you perform the Variable Effort Steering Diagnostic System Check?
--
Go to Step 2
Go to Diagnostic System Check - Variable Effort Steering

2
Install a scan tool.
Start the engine.
With the scan tool, observe the Magna Steer Commanded Current and the Magna Steer Feedback Current Data parameters in the Magna Steer data list.
Does the scan tool indicate that the Magna Steer Commanded and Magna Steer Feedback Current parameters are within .05 amps of each other and within specified range?
-1.84 to -1.99 A
Go to Testing for Intermittent and Poor Connections in Wiring Systems
Go to Step 3

3
Turn OFF the ignition.
Disconnect the VES actuator harness connector.
Measure the resistance of the VES actuator.
Does the resistance measure within the specified range?
1.6-3.1 ohms
Go to Step 4
Go to Step 10

4
Test the VES actuator and actuator harness for a short to ground. Refer to Testing for Short to Ground and to Wiring Repairs in Wiring Systems.

Was a short to ground located?
--
Go to Step 5
Go to Step 6

5
Visually inspect the actuator harness for any cut, chaffed or damaged wires.

Did you find and correct the condition?
--
Go to Step 14
Go to Step 12

6
Test the high effort control circuit of the VES actuator for a short to ground. Refer to Testing for Short to Ground and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?
--
Go to Step 14
Go to Step 7

7
Test the high effort control circuit of the VES actuator for an open or short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?
--
Go to Step 14
Go to Step 8

8
Test the low effort control circuit of the VES actuator for a short to ground. Refer to Testing for Short to Ground and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?
--
Go to Step 14
Go to Step 9

9
Test the low effort control circuit of the VES actuator for an open or short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?
--
Go to Step 14
Go to Step 11

10
Inspect for poor connections at the harness connector of the VES actuator. Refer to Testing for Intermittent and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?
--
Go to Step 14
Go to Step 12

11
Inspect for poor connections at the harness connector of the EBCM. Refer to Testing for Intermittent and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?
--
Go to Step 14
Go to Step 13

12
Replace the VES actuator. Refer to Power Steering Gear Replacement in Power Steering System.

Did you complete the repair?
--
Go to Step 14
--

13

Important
Perform the setup procedure for the EBCM. An unprogrammed EBCM will result in the following conditions:

Inoperative, or poorly functioning DRP/ABS/TCS/VSES/VES/TPM system, if equipped.
Set DTC C1248
Set DTC C1255

Replace the EBCM. Refer to Electronic Brake Control Module (EBCM) Replacement in Antilock Brake System.

Did you complete the repair?
--
Go to Step 14
--

14
Use the scan tool in order to clear the DTCs.
Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.
Does the DTC reset?
--
Go to Step 2
System OK




DTC P0410
Circuit Description
A secondary air injection (AIR) pump is used on this vehicle in order to lower the tail pipe emissions during start-up. The powertrain control module (PCM) supplies a ground to the AIR pump relay, which energizes the AIR pump.

The PCM monitors the heated oxygen sensor (HO2S) voltages in order to diagnose the AIR system.

During the AIR test, the PCM activates the AIR pump during closed loop operation. When the AIR is activated, the PCM monitors the HO2S voltages, and monitors the short-term fuel trim values for both banks of the engine. If the AIR system is operating correctly, the HO2S voltages should be low, and the short-term fuel trim should be high.

If the PCM determines that the HO2S voltages for both banks did not respond with the expected results during the tests, DTC P0410 sets. If only 1 sensor responded, the PCM sets either DTC P1415 or DTC P1416. The active DTC indicates which bank has the inoperative AIR system.

Conditions for Running the DTC
DTCs P0101-P0103, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0125, P0171-P0175, P0200, P0300, P0335, P0336, P0351-P0358, P0440, P0442, P0443, P0446, P0449, P1120, P1220, P1221, P1258, or P1441 are not set.
The fuel level is more than 12.5 percent but less than 87.5 percent.
The engine is running for more than 30 seconds.
The maximum air flow is 22 g/s.
The air fuel ratio is 13.125:1.
The engine load is less than 40 percent.
The ignition voltage is more than 11.7 volts.
Vehicle speed is more than 15 km/h (25 mph).
The engine is not operating in any of the following modes:
Power enrichment
Decel fuel cut-off mode
The catalyst over temperature
The engine is operating in a closed loop for more than 15 seconds.
The engine speed is more than 850 RPM.
The engine coolant temperature (ECT) is between than -10°C to +110°C (14°F-230°F).
The intake air temperature (IAT) is between -10°C to +100°C (14°F-212°F).
The fuel system is operating in fuel trim cells 1, 2, 4, 5, or 6.
Conditions for Setting the DTC
If the AIR pump turns ON during a closed loop operation and the HO2S voltage does not fall below 222 mV for 1.3 seconds.

Or

If the AIR pump turns ON during a closed loop operation and the short-term fuel trim does not change more than a predetermined amount.

Action Taken When the DTC Sets
The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.
Conditions for Clearing the MIL/DTC
The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
Clear the MIL and the DTC with a scan tool.
Diagnostic Aids

Important
Before you service the PCM or the throttle actuator control (TAC), remove any debris from the module connector surfaces, and from the module connector gaskets. Verify that the gaskets are correctly installed. The gaskets prevent debris from contaminating the modules.
For any test that requires probing the PCM or probing a component harness connector, use the Connector Test Adapter Kit J 35616-A . Using this kit prevents damage to the component terminals and to the harness. Refer to Using Connector Test Adapters in Wiring Systems.

AIR Pump Relay Underhood Electrical Center Terminal Identification

Front of Vehicle

Left Side of Vehicle
Ignition
B+
Right Side of Vehicle

Pump Supply
Control


For an intermittent condition, refer to Intermittent Conditions .
An intermittent may be caused by any of the following conditions:
Low system air flow may cause this DTC to set.
Excessive exhaust system back pressure
Moisture, water or debris ingested into the AIR pump
Pinched, kinked, heat damaged, or deteriorated hoses or vacuum lines
Restrictions in the pump inlet, duct, or filter
An AIR pump that has become inoperative and shows signs of exhaust gases in the outlet port would indicate a check valve failure.
Thoroughly check any circuitry that is suspected of causing the intermittent complaint. Refer to Testing for Intermittent and Poor Connections .
If a repair is necessary, refer to Wiring Repairs or Connector Repairs .
Test Description
The numbers below refer to the step numbers on the diagnostic table.

If DTCs P0412 or P0418 are set, diagnose those DTCs first.

Inspects for excess resistance in all of the circuits that are associated with the AIR system.

This step tests for the battery voltage at the AIR pump relay.

This step tests for power to the AIR pump.

This step tests the ground circuit for the AIR pump.

This step tests for a grounded circuit between the AIR pump and the AIR pump relay.

A restriction in a hose or in a pipe, between the shut-off valve and the point where the system branches to each bank, causes the setting of this DTC . Inspect for kinks or for blockages from the AIR pump to the connection point where the AIR system divides.

Step
Action
Yes
No

Schematic Reference: Engine Controls Schematics

1
Did you perform the Diagnostic System Check-Engine Controls?
Go to Step 2
Go to Diagnostic System Check - Engine Controls

2
Is the AIR pump fuse or the ENG IGN 1 fuse OK?
Go to Step 3
Go to Step 11

3
Is DTC P0412 or P0418 active?
Go to Diagnostic Trouble Code (DTC) List
Go to Step 4

4
Turn ON the ignition, with the engine OFF.
Command the AIR pump relay on with the scan tool.
Does the AIR pump turn ON?
Go to Step 8
Go to Step 5

5
Turn OFF the ignition.
Remove the AIR pump relay.
Test the B+ supply circuit of the AIR pump relay coil for an open using a test lamp connected to ground. Refer to Diagnostic Aids for terminal identification.
Does the test lamp illuminate?
Go to Step 6
Go to Step 16

6
Install the AIR pump relay.
Disconnect the AIR pump electrical connector. Refer to Secondary Air Injection (AIR) Pump Replacement .
Connect a test lamp to battery ground.
Probe terminal A of the AIR pump electrical connector. Refer to Probing Electrical Connectors in Wiring Systems.
Turn ON the ignition, with the engine OFF.
Command the AIR system ON with a scan tool.
Does the test lamp illuminate?
Go to Step 7
Go to Step 17

7
Test the ground circuit of the AIR pump for an open or poor ground connection using a test lamp connected to B+ and probing the B terminal of the AIR pump electrical.

Is the test lamp illuminated?
Go to Step 27
Go to Step 18

8
Turn OFF the ignition.
Disconnect the AIR pump outlet hose from the AIR pump.
Turn ON the ignition, with the engine OFF.
Command the AIR system ON with a scan tool.
Is air flow present at the AIR pump outlet?
Go to Step 9
Go to Step 10

9
Turn OFF the ignition.
Disconnect the vacuum hose from the AIR shut off valve.
Start the engine.
Command the AIR solenoid ON with a scan tool.
Is a vacuum present at the AIR shut-off valve?
Go to Step 14
Go to Step 19

10
Inspect for a restriction or for a blockage in the AIR Pump inlet hoses and in the AIR Pump inlet pipes.
If you find a restriction or a blockage in the AIR hoses and in the pipes, repair the restriction as necessary.
Did you find and correct the condition?
Go to Step 29
Go to Step 28

11
Turn OFF the ignition.
Remove the AIR pump relay.
Connect a test lamp to B+.
Test the B+ supply to the AIR pump and the AIR pump relay coil at the relay connector for a short to ground using a test lamp. Refer to Probing Electrical Connectors .
Refer to Diagnostic Aids for connector terminal identification.
Does the test lamp illuminate?
Go to Step 23
Go to Step 12

12
Disconnect the AIR pump electrical connector.
Connect a test lamp to B+.
Test the AIR pump connector terminal A with a test lamp for a short to ground.
Does the test lamp illuminate?
Go to Step 24
Go to Step 13

13
Install the AIR pump electrical connector.
Install a new AIR pump fuse.
Install the AIR pump relay.
Turn ON the ignition, with the engine OFF.
Command the AIR system ON with a scan tool.
Does the AIR pump fuse open?
Go to Step 28
Go to Diagnostic Aids

14
Install the following components:
The AIR pump outlet hose to the AIR pump
The vacuum hose to the AIR shut-off valve
Disconnect the outlet hose of the AIR shut-off valve.
Start and idle the engine.
Command the AIR system with a scan tool.
Is air present at the outlet of the AIR shut-off valve?
Go to Step 22
Go to Step 15

15
Replace the AIR shut-off valve. Refer to Secondary Air Injection (AIR) Shut-Off Valve Replacement .

Did you complete the action?
Go to Step 29
--

16
Repair the open in the B+ supply circuit to the AIR pump relay connector. Refer to Wiring Repairs in Wiring Systems.

Did you complete the action?
Go to Step 29
--

17
Repair the open in the AIR pump load circuit between the AIR pump relay and the AIR pump connector. Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?
Go to Step 29
Go to Step 25

18
Repair the poor ground connection or the open ground circuit of the AIR pump. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?
Go to Step 29
--

19
Turn OFF the ignition.
Disconnect the source vacuum hose from the AIR Solenoid Valve. Refer to Secondary Air Injection (AIR) Vacuum Control Solenoid Valve Replacement .
Start and idle the engine.
Is a vacuum present at the AIR solenoid valve?
Go to Step 20
Go to Step 21

20
Turn OFF the ignition.
Connect the source vacuum hose to the AIR solenoid valve.
Disconnect the vacuum hose to the AIR shut-off valve at the AIR solenoid valve.
Start and idle the engine.
Command the AIR solenoid valve ON with a scan tool.
Is a vacuum present at the AIR Solenoid Valve outlet?
Go to Step 21
Go to Step 26

21
Repair the restriction, the blockage, or the damage to the vacuum hose.

Did you complete the repair?
Go to Step 29
--

22
Repair the conditions in the AIR hose between the AIR shut-off valve and the point where the system branches to both sides of the engine.

Did you complete the repair?
Go to Step 29
--

23
Repair the short to ground in the ignition positive voltage circuit between the fuse and the relay. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?
Go to Step 29
--

24
Repair the short to ground in the circuit between the AIR pump relay and the AIR pump. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?
Go to Step 29
--

25
Replace the AIR pump relay.

Did you complete the replacement?
Go to Step 29
--

26
Replace the AIR Solenoid Valve. Refer to Secondary Air Injection (AIR) Vacuum Control Solenoid Valve Replacement .

Did you complete the replacement?
Go to s Step 29
--

27
Inspect for poor connections at the AIR pump electrical connector. Refer to Testing for Intermittent and Poor Connections in Wiring Systems.
If you find a poor connection, repair the terminal as necessary. Refer to Repairing Connector Terminals in Wiring Systems.
Did you find and correct the condition?
Go to Step 29
Go to Step 28

28
Replace the AIR pump. Refer to Secondary Air Injection (AIR) Pump Replacement .

Did you complete the replacement?
Go to Step 29
--

29
Clear the DTCs with a scan tool.
Turn OFF the ignition for 30 seconds.
Start the engine.
Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.
Does the DTC run, and pass?
Go to Step 30
Go to Step 2

30
Use a scan tool in order to observe the stored information in Capture Info.

Does the scan tool display any DTCs that you have not diagnosed?
Go to Diagnostic Trouble Code (DTC) List
System OK

 

Thanks Byron Hubter for the information.
I'm not giving up yet. I'm going to recheck the connection at the Steering Columm, the ECBM.
Just a few more q's.
First The Pump (P0410) , Is it the high pitch low noice sound that I hear when I start my car in te mornings? Before, I could hear the devise Fan/Pump starting and after a few minutes shutdown. As of last week, I noticed the devise starting and stopping "cycling". I never heard that before and felt that that not normal. This morning I did not hear it at all. Is that the Air pump? Also, i think it located at the front of the car.
The Magna Steering.......Dealer Issue. beside checking the connections and the ECBM, theirs nothing I can do the correct it.
last question. Can you tell me where the ECBM and ther PCM nodes are located?

Thanks

 

PCM down low, behind right front wheel. For ECBM, what year?

 

98 Coupe.