Operation CHARM: Car repair manuals for everyone.

Part 6






Signal too high (Continued)

Checking throttle position (TP) sensor signal








- Ignition off.
- Connect throttle position (TP) sensor.
- Start engine.
- Select Volvo Scan Tool (ST) to read off the throttle angle.





The throttle angle should be 0° when the engine is idling and should increase as the accelerator pedal (AP) is depressed.

OK - The cause of the diagnostic trouble code (DTC) has been loose connections in the throttle position (TP) sensor connector. Check connector for contact resistance and oxidation and remedy according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault. Then continue with Verification.
Checking for contact resistance and oxidation

Not OK - Try a new throttle position (TP) sensor. Then continue with Verification.
Replacing component

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

Checking for contact resistance and oxidation
The cause of the diagnostic trouble code (DTC) has been loose connections in the throttle position (TP) sensor 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 throttle position (TP) sensor.





Continue - Verification

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

Verification




Verification

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








- Ignition off.
- Throttle position (TP) sensor and engine control module (ECM) connected.
- Ignition on.
- Select Volvo Scan Tool (ST) to read off the value of the throttle position (TP) sensor.





At closed throttle position (CTP) voltage should exceed 0.1 V, at wide open throttle (WOT) voltage should be below 4.9 V.

OK - VERIFIED

Not OK - VERIFICATION FAILED

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

VERIFIED - FAULT FOUND

VERIFICATION FAILED - Fault-tracing information

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

Fault-tracing information
Information
Attempt New Test - Checking power cable

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

FAULT FOUND - Verification

No Fault Found - Verification

FAULT-TRACING FAILED - Verification

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

Checking for a short-circuit
- Check cable between transmission control module (TCM) #B20 and engine control module (ECM) #B20 for the Fenix 5.2, LH 3.2, Motronic 4.3 or Motronic 4.4 for a short-circuit to supply voltage according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.
- On cars with engine management system LH 3.2/EZ129K, also check the cable between engine control module (ECM) LH 3.2 #B20 and EZ129K #B20 for a short-circuit to supply voltage according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.





Select "Continue" when the fault has been repaired.

Continue - Verification

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

Checking voltage drop over the engine control module (ECM) signal ground.








- Ignition off.
- Control modules connected.
- Ignition on.
- Turn on as many power consuming components as possible.
Connect a voltmeter between ground terminal 31/33 and the breakout box:
- Fenix 5.2: #42 (#A42) signal ground
- LH 3.2: #20 (#A20) signal ground
- Motronic 4.3: #42 (#A42) signal ground
- Motronic 4.4: #42 (#A42) signal ground
Make a note of the voltmeter reading.









Continue - Checking voltage drop over the transmission control module (TCM) signal ground

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

Checking voltage drop over the transmission control module (TCM) signal ground








- Ignition off.
- Connect the control modules.
- Ignition on.
- Turn on as many power consuming components as possible.
Connect a voltmeter between ground terminal 31/33 and #20 (#A20) on the breakout box. Make a note of the reading. Add the previous reading to the new reading.









When added together the sum of the two readings should not be more than 0.1 V.

OK - Checking voltage drop over signal ground and power ground

Not OK - Checking for contact resistance and oxidation

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

Checking for contact resistance and oxidation




- Ignition off.
Check ground terminal 31/33 and transmission control module (TCM) connectors for contact resistance and oxidation according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.

Select "Continue" when the fault has been repaired.

Continue - Verification

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

Checking voltage drop over signal ground and power ground




- Ignition on.
- Turn on as many power consuming components as possible.
Connect a voltmeter between #20 (#A20) and #29 (#A29) on the breakout box.









The voltmeter should read less than 0.6 V.

OK - Checking throttle position (TP) sensor circuit

Not OK - Checking for contact resistance and oxidation

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

Checking for contact resistance and oxidation




- Ignition off.
Check ground terminals 31/32 and 31/33, the cables between the ground terminals and control module #A20 and #A29, and the control module connector for contact resistance and oxidation according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.

Select "Continue" when the fault has been repaired.

Continue - Verification

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

Verification




Verification

Hint: After repairs have been completed they must be verified as follows to ensure the fault has been eliminated:








- Ignition off
- Reconnect the connectors, reinstall components etc.
- Ignition on.
- Push down the accelerator pedal (AP) to wide open throttle (WOT) and keep it fully depressed
- Wait approx. 15 seconds.
Read off the status of the Diagnostic trouble code (DTC).





Does the status indicate INTERMITTENT FAULT?

Yes - VERIFIED

No - VERIFICATION FAILED

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

VERIFIED - FAULT FOUND

VERIFICATION FAILED - Fault-tracing information

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

Fault-tracing information
Information
Attempt New Test - Status message

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

Checking throttle position (TP) sensor circuit
Further fault-tracing depends on the vehicle's engine control module (ECM).

Select control module.

Fenix 5.2 - Connecting up the Test box to Fenix 5.2

LH 3.2 - Connection of test box to MFI module

Motronic 4.3 - Connecting up the Test box to Motronic 4.3

Motronic 4.4 - Troubleshooting Information

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






Connecting test box
951 1351 ADAPTOR 86-PIN 951 1351 Adaptor 86-Pin 981 3190 Replaced by 9511428 981 3190 Replaced by 951 1428
Connecting up the Test box to Fenix 5.2





Is the test box connected to the control module?

Yes - FAULT FOUND

No - Connecting test box to connector B (grey)

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

Connecting test box to connector B (grey)








- Ignition off.
- Disconnect control module.
- Connect adapter 951 1351 ADAPTOR 86-PIN 951 1351 Adaptor 86-Pin to control module connector.
- Connect test box 981 3190 Replaced by 9511428 981 3190 Replaced by 951 1428 to adapter, connector B.





Press Continue.

Continue - No Fault Found

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

CONNECTED - Checking voltage drop over the engine control module (ECM) signal ground

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






Connection of test box, MFI
981 3195 ADAPTOR 981 3195 Adaptor 981 3190 Replaced by 9511428 981 3190 Replaced by 951 1428
Connection of test box to MFI module





Is test box connected to MFI module?

Yes - No Fault Found

No -

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

Connection of test box to MFI module








- Switch off ignition.
- Disconnect MFI module.
- Plug adapter 981 3195 ADAPTOR 981 3195 Adaptor into MFI module connector.
- Connect test box 981 3190 Replaced by 9511428 981 3190 Replaced by 951 1428 to adapter.





Continue -

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

Checking ground terminals








- Switch off ignition
- Switch off all power consumers, such as interior lighting and radio.




- Use ohmmeter to measure resistance
- between #A20 (A20) on test box and battery negative terminal, and
- between #A29 (A29) on test box and battery negative terminal.

Instrument should indicate approx. 0 ohms in both cases.

OK - Resume fault tracing at point of interruption.
No Fault Found

Not OK - Check ground terminals 31/32 and 31/33 on engine and associated wiring for open-circuit as per Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault and for contact resistance as per Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.Check ground lead between engine and chassis for open- circuit as per Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault and for contact resistance as per Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.

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

Checking for open-circuit




- Check ground terminals 31/32 and 31/33 on engine and associated wiring for open-circuit as per Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault and for contact resistance as per Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.
- Check ground lead between engine and chassis for open- circuit as per Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault and for contact resistance as per Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.





Press Continue when fault is repaired.

Continue -

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

Verification

Hint: After repair, it is necessary to check that the fault has been corrected as described below:












- Switch off ignition
- Reconnect connectors.
- Switch off all power consumers, such as interior lighting and radio.
- Use ohmmeter to measure resistance
- between #A20 (A20) on test box and battery negative terminal, and
- between #A29 (A29) on test box and battery negative terminal.

Instrument should indicate approx. 0 ohms in both cases.

OK - FAULT FOUND

Not OK -

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

Troubleshooting Information
Information
Attempt New Test -

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

CONNECTED - Checking voltage drop over the engine control module (ECM) signal ground

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






Connector A
951 1351 ADAPTOR 86-PIN 951 1351 Adaptor 86-Pin 981 3190 Replaced by 9511428 981 3190 Replaced by 951 1428
Connecting up the Test box to Motronic 4.3





Is the test box connected to the control module?

Yes - FAULT FOUND

No -

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

Connection of break-out box to connector A (black)








- Switch off ignition.
- Disconnect ECM.

Note! The ECM must not be removed from the car until the main relay has interrupted the supply. This may take up to 150 seconds after the ignition has been switched off.

- Plug adapter 951 1351 ADAPTOR 86-PIN 951 1351 Adaptor 86-Pin into ECM base and connect break-out box 981 3190 Replaced by 9511428 981 3190 Replaced by 951 1428 to adapter.





Press Continue.

Continue -

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

Checking ground terminals








- Switch off ignition.
- Switch off all power consumers, such as interior lighting and radio.








- Use ohmmeter to measure resistance between battery negative terminal and
- #13 (#A13) on break-out box
- #28 (#A28) on break-out box
- #42 (#A42) on break-out box

Instrument should indicate approx. 0 ohms in all cases.

OK - Resume fault tracing at point of interruption.
No Fault Found

Not OK - Check ground terminals 31/32 and 31/33 at rear of engine and associated wiring for open-circuit as per Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault , and for contact resistance and oxidation as per Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.Check ground lead between engine and chassis for open-circuit as per Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault , and for contact resistance and oxidation as per Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.

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

Checking for open-circuit, contact resistance and oxidation




- Check ground terminals 31/32 and 31/33 at rear of engine and associated wiring for open-circuit as per Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault , and for contact resistance and oxidation as per Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.
- Check ground lead between engine and chassis for open-circuit as per Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault , and for contact resistance and oxidation as per Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.





Press Continue when fault is repaired.

Continue -

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

Verification

Hint: After repair, it is necessary to check that the fault has been corrected.
Perform as described below.




- Switch off ignition.
- Switch off all power consumers, such as interior lighting and radio.




- Use ohmmeter to measure resistance between battery negative terminal and
- #13 (#A13) on break-out box
- #28 (#A28) on break-out box
- #42 (#A42) on break-out box

Instrument should indicate approx. 0 ohms in all cases.

OK - FAULT FOUND

Not OK -

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

Troubleshooting Information
Information
Attempt New Test -

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

CONNECTED - Checking voltage drop over the engine control module (ECM) signal ground

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

Connector A
CONNECTED - Checking voltage drop over the engine control module (ECM) signal ground

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