1998 JAGUAR X308 check engine

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

Connect the scan tool 1
Have the DTC(s) and freeze frame data been recorded?
Yes GO to D2
D2: CHECK FOR LOW EXHAUST TEMPERATURE
Check the engine and exhaust system for correct operation
and normal running temperature 1
Is the engine and exhaust system operating correctly and up to
normal running temperature?
Yes GO to D3
No Rectify leaking exhaust manifold / catalyst, general causes of
an over rich mixture and engine cooling system operation
and test the system for correct operation.
GO to D7
D3: 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 EM022/001 and EM022/002. 2

Is the voltage between 600mV and 1.0 Volt?
Yes GO to D4
No Renew O2 sensor; reconnect plug(s).
GO to D7
D4: CHECK FOR O2 SENSOR FAILURE
With the conditions held as D3, suddenly decelerate to idle. 1
Has the voltage dropped to 400mV or less ?
Yes Stop the engine
GO to D5
No Renew O2 sensor. Reconnect plug(s)
GO to D7
D5: CHECK FOR O2 SENSOR FAILURE

With the conditions held as in D5, 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 D8
No Renew O2 sensor. Reconnect plug(s).
GO to D7
D7: 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
D8: CHECK FOR O2 SENSOR CONTINUITY

Connect the scan tool 1
Have the DTC(s) and freeze frame data been recorded?
Yes GO to E2
E2: CHECK 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 E3
No Renew O2 sensor. Reconnect plug(s)
GO to E7
E3: 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
With EM023 disconnected, measure the voltage between
EM023/003 and EM023/004. 2
Is the voltage between 600mV and 1.0 Volt?
Yes
GO to E4
No Renew O2 sensor. Reconnect plug(s)
GO to E7
E4: CHECK FOR O2 SENSOR FAILURE

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?