Faulty Signal. Permanent Fault

Faulty signal. Permanent fault

EFI-143 Front knock sensor (KS), signal; EFI-433 Rear knock sensor (KS), signal

Checking ground lead

- Ignition off.
- Wait for approximately 150 seconds (cars with immobilizer 245 seconds).
- Disconnect knock sensors (KS). Knock sensor (KS) connectors are located on the cable duct in front of the engine.
Connect an ohmmeter between knock sensor (KS) connector terminal 2 (engine control module (ECM) side) and ground.

The ohmmeter should read approximately 0 ohms.

OK - Checking the signal cable

Not OK - Checking control module connector

-------------------------------------------------

Checking control module connector

- Ignition off.
- Knock sensor (KS) disconnected.
- Check control module connector for contact resistance and oxidation and remedy according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.
- Control module connected.
Connect an ohmmeter between knock sensor (KS) connector terminal 2 and ground.

The ohmmeter should read approximately 0 ohms.

OK - Fault-tracing information

Not OK - Checking for an open-circuit

-------------------------------------------------

Fault-tracing information
The cause of the diagnostic trouble code (DTC) has been loose connections in the control module connector.

Continue - Verification

-------------------------------------------------

Checking for an open-circuit

- Check cable between knock sensor (KS) connector terminal 2 and engine control module (ECM) #A17 for an open-circuit according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.

Continue - Verification

-------------------------------------------------

Checking the signal cable

- Ignition off.
- Knock sensor (KS) disconnected.
Connect an ohmmeter between knock sensor (KS) connector terminal 1 (EFI-143) or terminal 3 (EFI-433) and ground.

The ohmmeter should read approximately 1 Mohms.

OK - Checking front knock sensor (KS) signal

Low - Checking for a short-circuit

High - Checking control module connector

-------------------------------------------------

Checking for a short-circuit

- Check cable between knock sensor (KS) terminal 1 and engine control module (ECM) #A2 (EFI-143) or terminal 3 and engine control module (ECM) #A30 (EFI-433) for a short-circuit to ground according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.

Continue - Verification

-------------------------------------------------

Checking control module connector

The ohmmeter should read approximately 1 Mohms.

OK - Fault-tracing information

Not OK - Checking for an open-circuit

-------------------------------------------------

Fault-tracing information
The cause of the diagnostic trouble code (DTC) has been loose connections in the control module connector.

Continue - Verification

-------------------------------------------------

Checking for an open-circuit

- Check cable between knock sensor (KS) terminal 1 and engine control module (ECM) #A2 (EFI-143) or terminal 3 and engine control module (ECM) #A30 (EFI-433) for an open-circuit according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.

Continue - Verification

-------------------------------------------------

Checking front knock sensor (KS) signal

- Ignition off.
- Connect the knock sensor (KS).
- Start engine and run to normal operating temperature.
- Rev engine to 3500 rpm.
Select Volvo Scan Tool (ST) to read off the value of the knock sensor (KS) signal.

This value should be 2 - 6 at engine speeds (RPM) above 3500 rpm.

OK - Checking rear knock sensor (KS) signal

Not OK - Replacing component

-------------------------------------------------

Checking rear knock sensor (KS) signal

- Knock sensor (KS) connected.
- Rev engine to 3500 rpm.
Select Volvo Scan Tool (ST) to read off the value of the knock sensor (KS) signal.

This value should be 2 - 6 at engine speeds (RPM) above 3500 rpm.

OK - Checking for contact resistance and oxidation

Not OK - Replacing component

-------------------------------------------------

Checking for contact resistance and oxidation
The diagnostic trouble code (DTC) has been caused by loose connections in the knock sensor (KS) connector.
- Check connector for contact resistance and oxidation and remedy according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.

Continue - Verification

-------------------------------------------------

Replacing component
- Try a new knock sensor (KS).

Continue - Verification

-------------------------------------------------

Verification

Verification

Hint: After carrying out the repair, check that the fault has been remedied as follows:

- Ignition off.
- Reinstall connectors, components etc.
- Start engine and run to normal operating temperature.
- Rev engine to 3500 rpm.

- Select Volvo Scan Tool (ST) to read off the value from the front knock sensor (KS).

This value should be 2-6 at engine speeds (RPM) above 3000 rpm.

OK - Verification, continued

Not OK - VERIFICATION FAILED

------------------------

Verification, continued

- Rev engine to 3500 rpm.

- Select Volvo Scan Tool (ST) to read off the value from the rear knock sensor (KS).

This value should be 2-6 at engine speeds (RPM) above 3000 rpm.

OK - VERIFIED

Not OK - VERIFICATION FAILED

------------------------

VERIFIED - FAULT FOUND

VERIFICATION FAILED - Fault-tracing information

-------------------------------------------------

Fault-tracing information

Information

Fault-tracing information
The fault should have been detected and remedied. As this is not the case fault-tracing has failed.
Exit fault-tracing for this diagnostic trouble code (DTC) or make another attempt.

Do you want to exit fault-tracing?

Yes - Exit fault-tracing

No - Attempt New Test

------------------------

Attempt New Test - Checking ground lead

-------------------------------------------------