1998 JAGUAR X308 Speed Sensor

Automatic Transmission/Transaxle - 4.0L SC V8 - AJ26 - Diagnostic
Strategy
Diagnosis and Testing
Symptom Chart
Symptom Chart
Special Tool(s)

Digital multimeter

Generic scantool
SymptomPossible SourcesAction
DTC P0740 Torque converter clutch system
electricalHarness fault
Connector pins(s) bent , loose or corroded
*
*GO to Pinpoint Test A
*
DTC P0740 Torque converter clutch system stuck
onTorque converter clutch stuck on
*GO to Pinpoint Test B
*
DTC P1744 Torque converter clutch system stuck
offTorque converter clutch stuck off
*GO to Pinpoint Test B
*
DTC P0702 Transmission control system electricalHarness fault
High side switch (FET) fault
Connector pins(s) bent , loose or corroded
*
*
*GO to Pinpoint Test C
or D
*
DTC P0753 Shift solenoid A electricalHarness fault
Solenoid open circuit
Solenoid short
Connector pins(s) bent
, loose or corroded
*
*
*
*GO to Pinpoint Test C *
DTC P0758 Shift solenoid B electricalHarness fault
Solenoid open circuit
Solenoid short
Connector pins(s) bent
, loose or corroded
*
*
*
*GO to Pinpoint Test C *
DTC P0763 Shift solenoid C electricalHarness fault
Solenoid open circuit
Solenoid short
Connector pins(s) bent
, loose or corroded
*
*
*
*GO to Pinpoint Test C *
DTC P0748 Pressure control solenoid electricalHarness fault
Pressure regulator open circuit
Pressure regulator short
Connector pins(s) bent
, loose or corroded
*
*
*
*GO to Pinpoint Test D *
DTC P1748 Pressure control solenoid B electricalHarness fault
Pressure regulator open circuit
Pressure regulator short
Connector pins(s) bent
, loose or corroded
*
*
*
*GO to Pinpoint Test D *
DTC P0702 Transmission control system electricalHarness fault
Speed sensor voltage supply out of
tolerance Connector pins(s) bent , loose or corroded
*
*
*GO to Pinpoint Test E
*
DTC P0715 Input / turbine speed sensor circuit
malfunctionSpeed sensor n2 or supply open circuit
Speed sensor n3
Harness fault
Connector pins(s) bent , loose or corroded
*
*
*
*GO to Pinpoint Test F
*
DTC P1601 Internal control module computer errorFaulty TCM
*GO to Pinpoint Test G *

With EM062 and GB001 disconnected, measure the
resistance between GB001/012 and EM062/033 1
Is the resistance < 0.5 OHM?
Yes GO to F4
No Inspect EM062, EM044 and GB001 for corrosion, bent /
pushed back pins or locate harness. Repair as necessary
and test the system fo r normal operation.
F4: CHECK SIGNAL CONTINUITY (N2 SPEED SENSOR)

With EM062 and GB001 disconnected, measure the
resistance between GB001/003 and EM062/012 1
Is the resistance < 0.5 OHM?
Yes Reconnect GB001
GO to F5
No Inspect EM062, EM044 and GB001 for corrosion, bent /
pushed back pins or locate harness. Repair as necessary
and test the system fo r normal operation.
F5: CHECK SIGNAL CONTINUITY (N3 SPEED SENSOR)

Connect the scan tool 1
Have the DTC(s) and freeze frame data been recorded?
Yes GO to A2
A2: CHECK O2 SENSOR HEATER CONTINUITY
Ignition switch to position 0 1
Disconnect EM021
Bracket on top of gearbox or Bulkhead rear of engine
2
With EM021 disconnected, measure the resistance between
EM021/001 and EM021/002. 3
Is the resistance between 4 and 10 OHM?
Yes
GO to A3
No Renew O2 sensor; reconnect plug(s)
GO to A6
A3: 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
Disconnect EM021 2

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 EM021/003 and EM021/004. 2
Is the voltage between 600mV and 1.0 Volt?
Yes
GO to B5
No Renew O2 sensor, reconnect plug(s).
GO to B8
B5: CHECK FOR O2 SENSOR FAILURE
With the conditions held as B4, suddenly decelerate to idle. 1
Has the voltage dropped to 400mV or less ?
Yes GO to B6
No Renew O2 sensor, reconnect plug(s).
GO to B8
B6: CHECK FOR O2 SENSOR FAILURE
With the conditions held as B5, suddenly accelerate to
approximately 2500 rpm. 1
Has the voltage risen to between 600mV and 1 volt?
Yes

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

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

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