Resetting computer after O2 sensor replacement

NCBill · Post by **NCBill** » 02 Feb 2009, 14:51

1997 850, non-turbo, stick shift, 170,000 miles

Took car in because check engine light was on. Rear O2 sensor was replaced. The light is now OFF, however, the shop says it still won't pass inspection because some codes still come up. They drove it several miles "to reset the computer." This is not a Volvo shop, but it's one of the best shops around. They said drive it for a few days and come back to see if it has reset.

If in a few days, it hasn't reset, does anyone have any idea what my options are?

Post by **MadeInJapan** » 02 Feb 2009, 15:29

They were hoping your car would go through a "readiness cycle" by driving it a few days. That probably won't do it. Unless you do what's prescribed by Volvo in this thread: https://www.matthewsvolvosite.com/forums ... rive+cycle your codes probably won't show a "readiness" state to be tested for emissions. If you don't want to hassle with this, keep driving it with varied driving. Every time you disconnect the battery your car has to be "readied" again.

Post by **Ozark Lee** » 02 Feb 2009, 15:35

From the Volvo TSB via allexperts.com:

Readiness / drive / cycle VOLVO 850 / 960 / S70 /S90

1996 Volvo 850 GLT L5-2.5L DOHC VIN 55 B5254S
Vehicle Level Technical Service Bulletins All Technical Service Bulletins Emissions - Establishing OBDII Readiness Codes

Emissions - Establishing OBDII Readiness Codes
Notes

NO: 25-19

DATE: 6-30-2004
MODEL:
960 - S/V 90/850/S70/V70/C70

M. YEAR:
1996-1998

SUBJECT:
Establishing Readiness for OBD II

DESCRIPTION:

As part of vehicle inspection programs various states have introduced a check of the vehicle Onboard Diagnostic System (OBD II). This inspection will check the operation of the malfunction indicator lamp (MIL), and scan for Diagnostic Trouble Codes (DTCs) and OBD II Readiness Codes within the electronic emission control system.

These programs have been introduced at the request of various State or Federal government agencies to assist states in meeting Clean Air Standards as required by Federal law and are applicable to all model year 1996 and later light-duty vehicles.

The OBD II system is a comprehensive system that is part of the vehicle Engine Management System that helps diagnose potential faults within the emission control system. The monitors within the OBD II system can provide very useful information about the status of the on board emission control system. These monitors indicate whether the emission system is, or is not, operating correctly and provide a fault code to help identify the malfunctioning system or component. This eliminates the traditional tail pipe exhaust gas test and expediting the inspection process.

Readiness is the method used to confirm that all of the engine management system emissions related on-board diagnostics have run successfully and no faults were detected. Readiness is only an indication that the diagnostic has run successfully The MY 1996 to 1998 Volvo are 'TRIP' based for establishing readiness. This requires two 'TRIPS' to be completed in order to reset readiness codes from 'NOT READY' to 'READY'. A 'TRIP' is identified in the Engine Management System Service Manuals TP 2308202 M 4.4, section KKKK, TP 2301202 M 4.3, section EBU, and TP2321201 M 4.4 (900) section VVV.

Following the procedures in these manuals may not allow all of the diagnostic monitors to run. The instructions listed in this bulletin will exercise all of the diagnostic monitors on these models. Upon completion of two trips and no diagnostic trouble codes are present; the readiness codes should be set to 'READY'.

A monitor remaining 'NOT READY' only indicates that the driving conditions for the diagnostic to run have not yet been met. There are several reasons the monitor status may be 'NOT READY', such as;

1. The battery has been disconnected for service and the ECM memory is erased.

2. A DTC has been erased from the ECM, resulting in readiness is re-set to 'NOT READY'

3. The driver may not normally drive far enough or in a pattern that readiness is completed during the drive.

General Instructions

1. No Diagnostic Trouble Codes (DTC) should be present in the ECM or TCM.

2. Fly wheel adaptation must be completed before diagnostics can run (Refer to Driving to change the flywheel status to "Ready").

3. Connect Volvo Systems Tester (VST). Enter the DIAGNOSTIC CHECK menu to verify if a trip has been completed as shown. Please Note: If using a scan tool other than the VST, different terms for reporting the same status may be displayed. 'READY' may be displayed as 'COMPLETE' and, 'NOT READY' may be displayed as INCOMPLETE'.

4. In order to insure EVAP leakage detection completion, the fuel level in the car should be above 1/4 and below 3/4 tank.

5. Air conditioning (A/C) must be off during idle periods. A/C compressor activation during the EVAP diagnostic may interrupt the EVAP test.

6. Select a suitable route where it is possible to achieve necessary speed and load conditions and occasionally stop at the side of the road safely. This needs to be done while obeying all traffic regulations and posted speed limits.

7. Important: Keep as steady a throttle pedal as possible when driving.

8. Engine temperature at start must be between + 29°C (84°F) to + 49°C (122°F). If engine temperature is below + 29°C, start engine to warm up over + 29°and then shut off. Restart engine when coolant temperature is between + 29°C and + 49°C.

Driving Sequence

A VST can be used to monitor the status of each readiness code. The readiness code is identified by a corresponding DTC/EFI code. As each readiness code is completed the DTC/EFI code will drop off the screen.

1. Drive a normal urban driving cycle for 6 minutes. Accelerate gently where necessary keeping the throttle as steady as possible. Moving the throttle and changing loads may interrupt individual diagnostics requiring a longer drive time.

2. Safely stop the vehicle and allow the engine to idle for 1-1/2 minutes. Fuel trim adaptations should be checked during this stop, DTC/EFI 231 and 232.

3. Drive a normal urban driving cycle for 6 minutes. Accelerate gently where necessary keeping the throttle as steady as possible.

4. Safely stop the vehicle and allow the engine to idle for 2-3 minutes. Secondary air system should be checked at this stop, DTC/EFI 442, 445 and 448.

5. Accelerate normally to a road speed over 45 MPH and try to keep the engine between 1800-2200 RPM. With an automatic transmission select 3rd or 4th gear. It is most important to keep the throttle pedal as steady as possible. It is better to let the road speed or RPM fluctuate slightly and keep the pedal steady. Drive for 5-6 minutes.

6. Safely stop the vehicle and allow the engine to idle for 2-3 minutes. Leakage diagnostics should be checked and at this time, DTC/EFI 611 and 612.

7. Accelerate normally to a road speed over 45 MPH and try to keep the engine between 1800-2200 RPM. With an automatic transmission select 3rd or 4th gear. It is most important to keep the throttle pedal as steady as possible. It is better to let the road speed or RPM fluctuate slightly and keep the pedal steady. Drive for 5 minutes.

8. Safely stop the vehicle and allow the engine to idle for 1-1/2 minutes.

9. Accelerate the vehicle normally to 1800-2000 RPM and then slow back down to a stop, repeat this step 4 times to set the cycle flag for idle air adaptation. The ECM needs 7 idle phases total to adapt. These four and the three previous stops will complete this check.

10. Stop car but do not shut off the engine. Using the VST check the trip/readiness status. If the trip is not 'COMPLETE', use the enter function on the VST to see the DTCs that remain 'NOT TESTED'. Use the detailed information following to meet the conditions necessary to allow the specific DTCs to be checked. If trip is 'COMPLETE' but readiness is 'NO', a second trip will be needed to establish readiness.

all diagnostic functions are NOT completed:

To determine which diagnostic functions have not been completed use the VST and enter the DIAGNOSTIC CHECK menu. At the TRIP/READINESS window press enter. The EFI codes representing individual diagnostic functions will be displayed.

Note the codes that are NOT TESTED. For codes not tested it is possible to run only that portion of the TRIP. Listed below are the specifics on how individual codes can be addressed:^ DTC/EFI 233 - Adaptive Idle Air trim. After completing the trip and the function is not set, idle the engine for 60 seconds, press the accelerator and rev up the engine above 1500 RPM for a few seconds, return to idle for 60 seconds. Continue this until EFI 233 is completed.

^ DTC/EFI 425/436 - Rear oxygen sensor, Accelerate to at least 45 mph, drive for 5 minutes at 1800-2200 RPM.

^ DTC/EFI 611/612 - Fuel tank system. Run the quick test in VST for leakage detection monitoring. (ACTIVATION -> ACTIVATE DIAG -> LEAKAGE DIAGNOSIS)

^ DTC/EFI 442/445/448 - Pulsed Secondary Air Injection system. Run the Quick Test in VST for the Pulsed Secondary Air system monitoring (ACTIVATION -> ACTIVATE DIAG -> SAS DIAGNOSIS).

^ DTC/EFI 435 - Front heated oxygen sensor, slow response. Drive the car with an Engine speed between approximately 2200 to 2800 RPM and a load value between 1.1 to 1.8 ms (LOAD - TL in VST Monitor Test). If equipped with an automatic gearbox select a lower gear if necessary.

- Drive for 2 minutes at 1800-2200 RPM, manual gear box equipped gear selection dependent on vehicle speed.

- Accelerate directly to 3000 - 3500 rpm for 30 seconds, manual gear box equipped use third gear

- Reduce rpm to 1800 - 2200 for 2 minutes, manual gear box equipped use fifth gear

- Accelerate directly to 3000 - 3500 rpm for 30 seconds, manual gear box equipped use third gear

- Reduce rpm to 2300 - 2500 for 2 minutes, manual gear box equipped use fourth gear

Flywheel Adaptation

Background:

The ECM monitors crankshaft speed variations to help detect misfire. In order to make misfire detection very accurate, the ECM uses an adaptive program to make sure that any variations in flywheel speed are due to the actions of misfire rather than small manufacturing tolerance variations which are normally present in the flywheel trigger wheel teeth. This adaptive process occurs naturally during normal driving.

If the battery is disconnected or if the Flywheel Adaptive values are reset, the Flywheel Adaptive Status ("F ADAP") will change from READY to NOT READY. In order to be able to successfully perform an OBD II 'TRIP', the flywheel status must be changed to READY before starting the 'TRIP'.

The Flywheel Adaptive program is only active during engine fuel cut-off. The program only adapts when the throttle is closed, the engine speed is decreasing, and the ECM is in fuel cutoff. That is the only time that crankshaft speed variation is so small that it is reliable to start the adaptive process. The ECM will use one section of the flywheel signal as a reference, and "adapt" the other sections of the signal so that they match.
After a certain period of time, when the ECM is satisfied that the different sections of the flywheel signal look the same, the adaptive process stops and the Flywheel Adaptive status changes to 'READY'.

Motronic 4.3

NOTE: The VST cannot read the flywheel adaptation on M 4.3 vehicles. Therefore the assumption is that they are not set. See driving instructions below to ensure flywheel adaptation is set.

Motronic 4.4

Flywheel adaptation must be completed (status 'READY') TIP: Look in the Monitor Test Scroll List and find the entry 'F ADAP'. It will say either 'READY' or 'NOT READY'. If it says 'READY', continue. If it says 'NOT READY', refer to previous illustration.

Driving to change the Flywheel Status to 'READY':- Connect the VST and go into the Monitor Test Scroll List

- Find the Flywheel Status and the Flywheel Adaptive values (F ADAP, F ADAP B, F ADAP C, etc.)

NOTE: These scroll list parameters are only available for M 4.4. The procedure works for M 4.3, but you cannot check to see if the Flywheel Adaptive Status has changed to 'READY'.
- Drive the car in second or third gear (2500 - 3500 rpm) and decelerate without using the brake (a long downhill is helpful for this but not necessary). The flywheel adaptive values should begin to change.

- Repeat the decelerations until the adaptive values stop changing. At that time, the Flywheel Status changes to 'READY'.

- Let the engine temperature cool down to between 29°C 49°C so you can begin the 'TRIP'.

Unique Characteristics

Motronic 4.3 and 4.4

The VST does not provide continuously updated online updates of the diagnostic status.

To check the status of readiness before, during or after a drive cycle, exit and re-enter the VST function. The screen will then be updated.

Turn air conditioning off during all stopped or idle periods, as the A/C load may cause a diagnosis to be interrupted. This will require more driving to get that diagnosis to run again.

Using the VST, it can be determined if all diagnostic functions were completed. To do so, enter the VST 'DIAGNOSTIC CHECK' menu. At the 'TRIP/READINESS' screen press enter to display the status of the DTCs that still need to be tested on the current trip. Refer to Driving Sequence for the specific instructions on how get individual diagnostics to run.

Motronic 4.3

Flywheel adaptation needs to be "ready" before a trip can be completed, on Motronic 4.3 the VST cannot read the flywheel adaptation status, therefore we should assume the adaptations are not set and follow the "Flywheel Adaptation Procedure" before continuing with the first trip.

When interrogated using a generic OBD II scan tool the MY 1996 Volvo 850 equipped with Bosch Motronic 4.3 Engine Management System, may experience all of the Readiness Codes changing from 'COMPLETE' to 'INCOMPLETE' when the ignition key is cycled. This behavior applies to all 1996 M 4.3 850s and cannot be corrected. DO NOT turn the engine off until after the Enhanced Inspection/Maintenance OBD II check has been completed.

Readiness status cannot be read from a vehicle equipped with Motronic 4.3 using the VST, but the completion of two 'TRIPS' will establish readiness.

MY 96 850 non-turbo: Run first test as described. Prior to running second trip activate SAS and Leakage diagnostic test. The second trip can be started with the engine at operating temperature. The coolant temperature can be read out from the 'SCROLL LIST' using the VST.

Motronic 4.4

Flywheel adaptation needs to be 'READY' before a trip can be completed. Establish flywheel adaptation at beginning of first trip following instructions under "Driving Sequence", and then continue with Trip.- Engine temperature at start must be between +29°C (84°F) + 49°C (122°F). If engine temperature is below + 29°C, start engine to warm up over + 29°C and then shut off. Restart engine when coolant temperature is between + 29°C and + 49°C.

- Start engine, go directly from position 2 to position 3 do not cycle key. The EFI 112 status should then change from 'NOT TESTED' to 'TESTED'. This indicates that the ECU has seen the correct start criteria.

- Another confirmation that the ECU has seen the correct start criteria is to access the EFI code 112 in the 'DIAGNOSTIC CHECK' menu. With ignition key in pos. 2, engine off, access the 'DIAGNOSTIC CHECK' menu and press enter. The EFI codes will appear. Scroll down until you get to EFI 112

- 'READINESS YES or NO' can be read using the diagnostic function in the VST. 'YES' requiring the successful completion of two trips.

- 960/S/V 90 - It is not possible to complete the test for code 211. Code 211 is not valid for this market. The trip is completed when 'substitute trip' is displayed and the only code remaining is 211. Using the monitor test confirm that a trip has set by 'TRI P=YES'.

Editorial note:

My head hurts - Thank God I don't have smog tests.

...Lee

dcovey · Post by **dcovey** » 06 Feb 2009, 13:21

Option 1. Remove both battery cables, hold the ends together for 15 seconds to clear the DTC codes.

Option 2. Get an OBDII code reader pull the codes to make sure you don't have any other issues, use the tool to clear the codes.

Post by **MadeInJapan** » 06 Feb 2009, 16:24

The problem after clearing codes with either method #1 or #2, above, is that your car has to now go through each of it's systems to post to the ECU that they are ready. This is what we're talking about, above. Each time you reset your ECU, you're back to square one for readiness- which is essential if you're getting emissions testing done.

Post by **JRL** » 14 Jul 2010, 05:51

Can't do.
They should have known about the correct drive cycle but now that you've driven it already, continue.
You can have TWO not ready codes and it WILL PASS.
There are seven, a couple should have gone out right away.
Take it to an Autozone or whoever has a reader, Have them check again.
If it has only two (2) not ready codes TELL THEM to run the test, it will pass

Post by **pkc303** » 14 Jul 2010, 07:31

They are correct, you can keep driving, it will then get the OBDII ready. Like the previous response, you must have 2 of 3 ready. I had to drive about 75 miles in our 850R. Have fun, avoid cops.

ptaylor-01 · Post by **ptaylor-01** » 08 Aug 2010, 18:12

I have a 98 V70 AWD. A few weeks ago I replaced my smog pump, and check valve, then cleared the code. It's been weeks now, and I've driven over 500 miles, yet all but 3 I/O monitors are still flashing as not ready on my reader. I've also tried doing the drive cycle described in this thread, about 3 or 4 times. Is there something else I could try? Also, it's been very hot and humid where I live, do these monitors only cooperate in cooler weather or something? Thanks.

Post by **pkc303** » 12 Aug 2010, 21:53

How many miles have you driven? You either need to keep driving, or something else is wrong. Are you getting codes?