Oxygen Sensor Period Fault Code PO130/PO150 (17/03/97/NAS)

Publication date: 1997-12-19
Reference number: 17/03/97/NAS

OXYGEN SENSOR PERIOD FAULT CODE PO130/PO150

TECHNICAL SERVICE BULLETIN

Reference Number(s): 17/03/97/NAS, Date of Issue: December 19, 1997

OXYGEN SENSOR PERIOD FAULT CODE P0130/P0150

Model(s): 1996-97 Land Rover Discovery (LJ)

1997 Land Rover Defender 90 (LD) Reference: WSM Section 19 Issue: 3

Group: Fuel System

Bulletin Number: 17/03/97/NAS

Date: December 19, 1997

SITUATION

MIL ILLUMINATION, CODE P0130/P0150

NOTE: This information supersedes information given in Operation Pride article 1-13.

In some cases an Oxygen Sensor Period fault can be set and the MIL can be illuminated. In order to properly diagnose this fault the concept of an oxygen sensor period must be understood. The oxygen sensor period is defined as the time involved for the oxygen sensor signal to go from full rich through full lean and back to full inch again. See Fig 1 . GEMS will flag a fault code if the time involved for a full period is too long. GEMS uses a counter to allow for some abnormal switching of the Oxygen Sensor. Too many bad counts will flag a code. A fault may be set by a poorly switching sensor or, in some cases, a unique driving style.

Fig 1: Expected Oxygen Sensor Response For Snap Throttle Test

RESOLUTION

REPLACE GEMS PROM

Use the procedure detailed below to test the performance of the Oxygen Sensor. If the Oxygen Sensor operates properly the MIL illumination problem can be resolved by a software change to the PROM of the GEMS ECM.

NOTE: The repairs outlined in this TIB are to be performed to resolve customer complaint of the symptoms described.

PARTS INFORMATION

Part Number	Description
PRM9637	PROM (1996 Discovery-Automatic)
PRM9630	PROM (1996 Discovery-Manual)
PRM9643	PROM (1997 Discovery-Automatic, up to VA714241, VA546029)
PRM9644	PROM (1997 Discovery-Manual, up to VA714241, VA546029)
PRM9652	PROM (1997.5- Automatic, from VA714242, VA546030)
PRM9653	PROM (1997.5-Manual, from VA714242, VA546030)
PRM9642	PROM (D-90)
LRNASTATK	Anti-Static Mat

NOTE: PROM sets will only be released with the approval of the GEMS Helpline.

REPAIR PROCEDURE

Hook up Test Book and follow instructions.
Complete DTCR, recording all freeze-frame data.
Monitor H02s voltages and heater voltages. If any are out of specification, repair and retest.
Perform the oxygen sensor snap throttle test as outlined in TIB 17/01/96.
If the snap throttle test shows the sensor transition time, both rich to lean and lean to rich, to be good, DO NOT replace the sensor; look at the service history for other instances of this DTCR.
FAX DTCR to GEMS Helpline to get authorization to replace PROM set.
Reset engine adaptations and IACV to 20-25 steps.

WARRANTY INFORMATION

19.22.96: Test Book access codes, Uniscope analysis, DTCR and

Drive Cycle "C"

Time: 1.25 hrs.

19.22.89.29: Snap Throttle Test

Time: 0.25 hr.

18.30.89.26: Replace PROM Set

Time: 0.50 hr.

Comp Code: 7G1A

Normal warranty policy and procedures apply.