CAMPAIGN: OIL PRESSURE LIGHT COMES ON/ INSTALL PROM

MODELS/YEARS: 1986 & 197 TORONADO

CONDITION

General Motors has determined that all 1986 and certain 1987 Oldsmobile Toronado models were produced with a low engine oil presure warning system that could malfunction resulting in an erroneous low engine oil pressure warning to the vehicle driver.

To prevent the possibility of this condition occurring on 1986 models, dealers are to install a new EPROM in the body computer module (BCM), replace the three-terminal oil pressure switch with a new four-terminal oil pressure sensor, inspect the sensor wiring harness connector terminals for corrosion, and clean or replace the terminals if necessary.

To prevent the possibility of this condition occurring on 1987 models, installation of a new EPROM in the body computer module (BCM) is required.

VEHICLES INVOLVED

Involved are all 1986 and certain 1987 Oldsmobile Toronado models within the following VIN breakpoints.

Model Year Plant Beginning Up To And Including ----- ----- --------- ------------------- 1986 Hamtramck (U) Start of Production End of Production 1987 Hamtramck (U) Start of Production HU305043

DEALER ACTION

Dealers are to service all vehicles subject to this campaign at no charge to the owner, regardless of mileage, age of vehicle, or ownership, from this time forward.

Whenever a vehicle subject to this campaign is taken into your new or used vehicle inventory, or it is in your dealership for service in the future, you should take the steps necessary to be sure the campaign correction has been made before reselling or releasing the vehicle.

Owners of vehicles recently sold from your new vehicle inventory are to be contacted by the dealer and arrangements made to make the required modification according to instructions contained in this bulletin.

SERVICE PROCEDURE

If the vehicle is a 1986 model, begin with Part A of this service procedure. If the vehicle is a 1987 model, begin with Part C of this service Procedure.

A. Inspection

1. Open hood and install fender covers.

2. Locate and disengage connector from oil pressure switch, Refer to Figure 1.

3. Inspect top of oil pressure "switch" to determine if it is a three (3) terminal switch or a four (4) terminal sensor. (If vehicle is equipped with a four (4) terminal sensor, sensor replacement is not required.)

o If three (3) terminals are present (oil pressure switch), proceed to step 4 below. o If four (4) terminals are present (oil pressure sensor), proceed to step 5 below.

4. Remove switch, examine the three male terminals on switch for corrosion and install new oil pressure sensor, part number 1644131.

5. Using a good light, closely examine the female terminal ends in the sensor connector for corrosion.

o If there are any signs of corrosion on either the male terminal(s) of the removed oil pressure switch or the female connector terminal(s) it will be necessary to clean or replace the connector terminal(s). Proceed to Part B of this Service Procedure.

o If there are no signs of corrosion, inspect the connector seal to ensure it is free of any dirt or debris and then reconnect connector to oil pressure sensor. If connector seal is contaminated with dirt or grease, or appears damaged, replace with new seal contained in connector kit, part number 1643680. Refer to Parts information. Proceed to Part B, step 17 of this Service Procedure.

B. Oil Presure Sensor Connector Terminal Cleaning/Replacement

1. Disengage secondary lock from back of connector and remove.

2. Grasp wire and push terminal forward in connector.

3. Insert terminal removal tool into entry canal of connector and angle tool slightly to depress lock tang on terminal. Refer to Figure 2.

4. Gently pull on wire to remove terminal through back of connector.

5. If corrosion is white powder and only on contact surface of connector terminal (where mating to sensor terminal occurs), clean only with a standard contact cleaner, such as CRC Electra Clean, CRC Contact Cleaner or equivalent. Proceed to step 13.

6. If corrosion is a greenish powder on the contact surface and/or in the area of the crimp to wire, the affected terminal(s) must be replaced. Follow steps 7 thru 13 for each terminal affected.

7. Cut off old terminal between insulation wings and core wings. Refer to Figure 3. Pull off old seal and remaining piece of terminal.

8. Strip 1/4 inch of insulation off wire and install new wire seal.

9. Position wire into terminal, Figure 4.

10. With 18 gauge wire crimpers, crimp terminal core wings.

11. Using rosin core solder, solder hand crimped terminal(s) as shown in Figure 5.

12. Align wire seal with wire insulation (Figure 6) and use nose of wire crimpers to wrap the insulation wings around seal. (Wings around seal should just hold seal in place. DO NOT OVER CRIMP.)

13. Ensure terminal lock tang is properly formed and plug terminal back into correct cavity of connector, Figure 7.

14. Install new secondary lock on back of connector.

15. Inspect the connector seal to ensure it is free of any damage, dirt or debris. If connector seal is contaminated with dirt or grease, or appears damaged, replace with new seal.

16. Reconnect the connector to the oil pressure sensor.

17. Position connector harness away from the serpentine belt and secure with electrical tape.

18. Install new EPROM. Refer to Part C.

C. EPROM Installation

1. Open I.P. compartment door.

2. Disconnect stop straps.

3. Remove screws attaching door to hinge.

4. Remove I.P. compartment door.

5. Remove relay center bracket assembly and position aside.

6. Remove fuse panel and position aside.

7. With ignition switch off, remove electrical connectors from BCM and loosen nuts attaching BCM to bracket.

8. Remove BCM.

9. Remove four screws from access cover and remove cover. Refer to Figure 8.

10. Remove EPROM as follows: Using the rocker type PROM removal tool (Figure 8), engage one end of the EPROM carrier with the hook end of the tool. Press on the vertical bar end of the tool and rock the engaged end of the EPROM carrier up as far as possible. Engage the opposite end of the EPROM carrier in the same manner and rock this end up as far as possible. Repeat this process until the EPROM carrier and the EPROM are free of the EPROM socket.

11. Install new EPROM, mounted in carrier, in EPROM socket. Small notch in carrier must be aligned with small notch in socket. Press on EPROM carrier until it is firmly seated in the socket. Do not press on EPROM; only the carrier.

12. Install access cover and secure with four screws.

13. Reinstall BCM (reverse Steps 1 through 7).

14. Proceed to Part D of this service procedure.

D. Clear BCM Malfunction Code

To clear BCM codes, press the fan up (^) or fan down (V) buttons on the electronic climate control (ECC) panel (refer to Figure 9) as indicated in the following procedure while watching the instrument panel information display.

If an incorrect button is pressed during this procedure, press the BI-LEVEL button to exit diagnostics. Begin the procedure again by entering diagnostics as before.

E. Campaign Identification Label

Each vehicle modified in accordance with the instructions outlined in this procedure will require a Campaign Identification label. Each label provides a space to include the campaign number, the five (5) digit dealer code of the dealer performing the campaign service, and the date vehicle was campaigned. This information may be inserted with a typewriter or ballpoint pen. When installing label, clean the surface of the radiator upper mounting support and apply the campaign label where it is readily visible.

PARTS INFORMATION

Parts required to complete this correction are to be obtained from General Motors Service Parts Operations (GMSPO). To ensure these parts will be obtained as soon as possible, they should be ordered from GMSPO on a C.I.O. order with no special instruction code, but on an advise code (2).

Model Year Description Use Part Number Quantity ----------- ---------- ----------- --------

Oil Pressure Sensor 1986 1644131 1

Connector Kit* 1986 1643680 1 (If Required) EPROM 1986 1228416 1

EPROM 1987 16075597 1

*Connector Kit Contains: 4 Terminals 1 Wire Seal (Red) 3 Wire Seals (Blue) 1 Connector Seal 1 Secondary Lock

CLAIM INFORMATION

1986 MODELS ONLY - Determine if vehicle is equipped with three terminal oil pressure switch or four terminal oil pressure sensor. If equipped with three terminal switch, replace with four terminal sensor. (NOTE: If vehicle is equipped with four terminal sensor, sensor replacement is not required.) Inspect sensor connector terminals for corrosion. Replace EPROM.

Failure Code Labor Operation Labor Hours* ------------ --------------- ----------- 96 V3940 .6

1987 MODELS ONLY - install new EPROM.

Failure Code Labor Operation Labor Hours ------------ --------------- ----------- 96 V3941 .4

.1 hour clerical administration may be added to the above operation.

*Add: To clean one or all connector terminals .1 hour To replace connector terminal(s) .1 hour each

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.