1998 JAGUAR X308 sensor

With EM012 and EM021 disconnected, measure the
resistance between EM012/015 and EM021/003. 1
Is the resistance < 0.5 OHM?
Yes GO to B14
No Inspect harness / connectors EM012 and EM021 for
corrosion, damaged / pushed back pins. Repair as necessary
and reconnect plug(s).
GO to B19
B14: HEATED O2 SENSOR SCREEN GROUND CONTINUITY

Is the voltage 0 (zero) V?
Yes GO to B17
No Inspect harness / connectors EM010, EM012 and EM021 for
corrosion, damaged / pushed back pins. Repair as necessary
and reconnect plug(s).
GO to B19
B17: 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
Ignition switch to position II 5
Measure the voltage between EM010/023 and EM015/002. 6
Is the voltage 0 (zero) V?
Yes Replace EMS fuse F14 but retain link lead.
GO to B18
No Inspect harness / connectors EM010, EM015 and EM021 for
corrosion, damaged / pushed back pins. Repair as necessary
and reconnect plug(s).
GO to B19
B18: 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 C2
C2: CHECK FOR O2 SENSOR FAILURE
Ignition switch to position II 1
Disconnect EM022
Bracket on top of gearbox or Bulkhead rear of engine
2
Run the engine for a period to warm the sensor and then
maintain a steady speed of approximately 2500 rpm. 3
Measure the voltage between EM022/001 and EM022/002. 4
Is the voltage between 600mV and 1.0 Volt?
Yes
GO to C3
No Renew O2 sensor and reconnect plug(s).
GO to C6
C3: CHECK FOR O2 SENSOR FAILURE
With the conditions held as C2, suddenly decelerate to idle. 1
Has the voltage dropped to 400mV or less ?
Yes

GO to C4
No Renew O2 sensor and reconnect plug(s).
GO to C6
C4: CHECK FOR O2 SENSOR FAILURE
With the conditions held as C3, suddenly accelerate to
approximately 2500 rpm. 1
Has the voltage risen to between 600mV and 1 volt?
Yes GO to C5
No Renew O2 sensor and reconnect plug(s).
GO to C6
C5: CHECK FOR O2 SENSOR FAILURE

With the conditions held as in C4, run the engine at 1500
rpm for approximately 3 minutes. 1
Does the displayed voltage drop below 400mV and rise above 500
mV, cycling approximately every 180 seconds?
Yes GO to C7
No Renew O2 sensor and reconnect plug(s).
GO to C6
C6: 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
C7: CHECK FOR O2 SENSOR CONTINUITY

With EM012 and EM022 disconnected, measure the
resistance between EM012/017 and EM022/002. 1
Is the resistance < 0.5 OHM?
Yes GO to C8
No Inspect harness / connectors EM012 and EM022 for
corrosion, damaged / pushed back pins. Repair as necessary
and reconnect plug(s).
GO to C10
C8: O2 SENSOR SCREEN GROUND CONTINUITY

With EM012 and EM022 disconnected, measure the
resistance between EM012/022 and EM022/001. 1
Is the resistance < 0.5 OHM?
Yes GO to C9
No Inspect harness / connectors EM012 and EM022 for
corrosion, damaged / pushed back pins.
Inspect harness / splice EM S08 for damage. Repair as
necessary and reconnect plug(s).
GO to C10
C9: O2 SENSOR SHORT CIRCUIT TO GROUND