1998 JAGUAR X308 sensor

With EM012 and EM023 disconnected, measure the
resistance between EM012/014 and EM023/003. 1
Is the resistance < 0.5 OHM?
Yes GO to E13
No Inspect harness / connecto rs EM012, and EM023 for
corrosion, damaged / pushed back pins.
Repair as required an d reconnect plug(s).
GO to E18
E13: HEATED O2 SENSOR SCREEN GROUND CONTINUITY

With EM010 and EM012 disconnected, measure the
voltage between EM010/023 and EM012/022. 1
Is the voltage 0 (zero) V?
Yes GO to E16
No Inspect harness / connecto rs EM010, EM012 and EM023
for corrosion, damaged / pushed back pins.
Repair as required an d reconnect plug(s).
GO to E18
E16: CHECK FOR SHORT TO B+ AT O2 SENSOR HEATER

Ignition switch to position 0 1
Remove EMS fuse F14. 2
Disconnect EM010 and EM015. 3
Using a link lead, bridge EM010/016 and EM010/022. 4
Measure the voltage between EM010/023 and
EM015/001. 5
Is the voltage 0 (zero) V?
Yes Replace EMS fuse F14 but retain link lead.
GO to E17
No Inspect harness / connecto rs EM010, EM015, and EM023
for corrosion, damaged / pushed back pins.
Repair as required an d reconnect plug(s).
GO to E18
E17: CHECK B+ AT O2 SENSOR HEATER CIRCUIT

Connect the scan tool 1
Have the DTC(s) and freeze frame data been recorded?
Yes GO to F2
F2: CHECK FOR LOW EXHAUST TEMPERATURE
Check the engine and exhaust system for normal running
temperature 1
Is the engine and exhaust sy stem up to normal running
temperature?
Yes GO to F3
No Rectify possible leaking exhaust manifold / catalyst,
general causes of an over ri ch mixture and engine cooling
system operation. Test the sy stem for correct operation.
GO to F8
F3: CHECK FOR O2 SENSOR HEATER CONTINUITY
Ignition switch to position 0 1
Disconnect EM023
Bracket on top of gearbox or Bulkhead rear of engine
2
Measure the resistance between EM023/001 and
EM023/002. 3
Is the resistance between 4 and 10 OHM?
Yes
GO to F4
No Renew O2 sensor. Reconnect plug(s).
GO to F8
F4: CHECK FOR O2 SENSOR FAILURE

Run the engine for a period to warm the sensor and then
maintain a steady speed of approximately 2500 rpm. 1
Measure the voltage between EM023/003 and
EM023/004. 2
Is the voltage between 600mV and 1.0 Volt?
Yes
GO to F5
No Renew O2 sensor. Reconnect plug(s).
GO to F8
F5: CHECK FOR O2 SENSOR FAILURE
With the conditions held as F4, suddenly decelerate to
idle. 1
Has the voltage dropped to 400mV or less ?
Yes GO to F6
No Renew O2 sensor. Reconnect plug(s)
GO to F8
F6: CHECK FOR O2 SENSOR FAILURE
With the conditions held as F5, suddenly accelerate to
approximately 2500 rpm. 1
Has the voltage risen to between 600mV and 1 volt?

Yes GO to F7
No Renew O2 sensor. Reconnect plug(s)
GO to F8
F7: CHECK FOR O2 SENSOR FAILURE
With the conditions held as in F6, run the engine at 1500
rpm for approximately 2 minutes. 1
Does the displayed voltage drop below 400mV and rise above
500 mV, cycling approximately every 4 seconds?
Yes GO to F9
No Renew O2 sensor. Reconnect plug(s)
GO to F8
F8: STOP
Perform appropriate service drive cycle and check for the
presence of DTC. 1
Has the fault code cleared?
Yes STOP
No Contact Jaguar Service
F9: HEATED O2 SENSOR SHORT CIRCUIT TO GROUND

With EM023 disconnected measure the insulation
resistance between sensor pin 001 and sensor body. 1
Repeat for pin 003 and sensor body. 2
Is the resistance > 10 MOHM?
Yes
GO to F11
No Renew the O2 sensor and reconnect plug(s).
GO to F10
F10: STOP
Perform appropriate service drive cycle and check for the
presence of DTC. 1
Has the fault code cleared?
Yes STOP
No Contact Jaguar Service
F11: SIGNAL GROUND 1 CONTINUITY

With EM010 and EM014 disconnected, measure the
resistance between EM014/004 and chassis ground
EM008L. 1
Is the resistance < 0.5 OHM?
Yes GO to F14
No Inspect harness / connector EM014 for corrosion, damage,
or pushed back pin.
Inspect earthing stud EM008L for corrosion or damage.
Inspect harness / spli ce EMS38 for damage.
Repair as required an d reconnect plug(s).
GO to F13
F13: CHECK FOR HEATED O2 SENSOR CONTINUITY