1998 Jaguar XJR

I've been attempting to diagnose an ignition problem on my car and I believe I have it narrowed down to either the camshaft position sensor, crankshaft position sensor or the knock sensors. I was wondering if anyone knew if those sensors had a specific ohm or volt reading that you can get from them if you test them with a multimeter? I've searched on the forums and haven't found anything and I've searched alldatadiy but I can only find the torque specs for installing them and a graph for the voltage change on the camshaft position sensor but no resistance or volt ratings for them.

Is there a way to test any of these sensors? My car is throwing some codes but for whatever reason no OBD2 reader I've tried will interface with the car so I'm at a bit of a disadvantage in that sense.

I've tested every fuse and relay in the car and everything is good.

I've also checked my fuel pressure and it checks out according to alldatadiy which rates it at 42psi which is what I read from the fuel rail.

The timing chains didn't skip any teeth as the cam flats line up so I'm assuming my ignition problem is dealing with those sensors.

Any help would be appreciated.

 

JTIS pinpoint tests:

Knock sensors
P: DTC P0332, P0333; LEFT-HAND KNOCK SENSOR (KS) HIGH/LOW VOLTAGE
Note:
Before commencing this test, make sure that the sensor is making a good electrical contact with the cylinder block. See 'possible causes'.

P1: CHECK KS SENSE CIRCUIT FOR HIGH RESISTANCE
1. Disconnect the battery negative terminal.
2. Disconnect the KS electrical connector, PI27.
3. Disconnect the ECM electrical connector, EM83.
4. Measure the resistance between PI27, pin 01 (N) and EM83, pin 23 (N).
Is the resistance greater than 5 ohms?
-> Yes
REPAIR the high resistance circuit. For additional information, refer to the wiring diagrams. CLEAR the DTC. TEST the system for normal operation.
-> No
Goto <<P2>>

P2: CHECK KS SENSE CIRCUIT FOR SHORT TO HIGH VOLTAGE
1. Turn the ignition switch to the ON position.
2. Reconnect the battery negative terminal.
3. Measure the voltage between PI27, pin 01 (N) and GROUND.
Is the voltage greater than 3 volts?
-> Yes
REPAIR the short circuit to high voltage. For additional information, refer to the wiring diagrams. CLEAR the DTC. TEST the system for normal operation.
-> No
Goto <<P3>>

P3. CHECK KS SENSE CIRCUIT FOR SHORT TO GROUND
1. Turn the ignition switch to the OFF position.
2. Measure the resistance between PI27, pin 01 (N) and GROUND.
Is the resistance less than 10,000 ohms?
-> Yes
REPAIR the short circuit to GROUND. For additional information, refer to the wiring diagrams. CLEAR the DTC. TEST the system for normal operation.
-> No
INSTALL a new KS. CLEAR the DTC. TEST the system for normal operation.


Crankshaft position sensor

Q1: CHECK THE CKP SENSOR FOR CORRECT INSTALLATION

1. Turn the ignition switch to the OFF position.
2. Check the CKP sensor for correct installation.
Is the CKP sensor correctly installed?
-> Yes
Goto <<Q2>>
-> No
INSTALL the CKP sensor correctly. Reconnect the sensor. CLEAR the DTCs. TEST the system for normal operation.

Q2: CHECK THE CKP SENSOR FOR DEBRIS

1. Remove the CKP sensor and inspect for debris.
Is the CKP sensor free of debris?
-> Yes
Goto <<Q3>>
-> No
CLEAN the sensor and wheel. INSTALL the sensor. Reconnect the sensor. CLEAR the DTCs. TEST the system for normal operation.

Q3: CHECK THE CKP SENSOR SENSE CIRCUIT FOR HIGH RESISTANCE

1. Disconnect the battery negative terminal.
2. Disconnect the ECM electrical connector, EM83.
3. Measure the resistance between EM83, pin 08 (Y) and PI17, pin 02 (Y).
Is the resistance greater than 5 ohms?
-> Yes
REPAIR the high resistance circuit. For additional information, refer to the wiring diagrams. CLEAR the DTC. TEST the system for normal operation.
-> No
Goto <<Q4>>

Q4: CHECK THE CKP SENSOR SENSE CIRCUIT FOR SHORT TO HIGH VOLTAGE

1. Reconnect the battery negative terminal.
2. Turn the ignition switch to the ON position.
3. Measure the voltage between PI17, pin 02 (Y) and GROUND.
Is the voltage greater than 3 volts?
-> Yes
REPAIR the short circuit to high voltage. For additional information, refer to the wiring diagrams. CLEAR the DTC. TEST the system for normal operation.
-> No
Goto <<Q5>>

Q5: CHECK THE CKP SENSOR SENSE CIRCUIT FOR SHORT TO GROUND

1. Turn the ignition switch to the OFF position.
2. Measure the resistance between EM83, pin 08 (Y) and GROUND.
Is the resistance less than 10,000 ohms?
-> Yes
REPAIR the short circuit to GROUND. For additional information, refer to the wiring diagrams. CLEAR the DTC. TEST the system for normal operation.
-> No
INSTALL a new CKP sensor. CLEAR the DTC. TEST the system for normal operation.

CAMSHAFT POSITION SENSOR

R: DTC P0340, P0341; RIGHT-HAND CAMSHAFT POSITION (CMP) SENSOR CIRCUIT MALFUNCTION, RANGE/PERFORMANCE

R1: CHECK THE CMP SENSOR FOR CORRECT INSTALLATION
1. Turn the ignition switch to the OFF position.
2. Check the CMP sensor for correct installation.
Is the CMP sensor correctly installed?
-> Yes
Goto <<R2>>
-> No
INSTALL the CMP sensor correctly. CLEAR the DTCs. TEST the system for normal operation.

R2: CHECK THE CMP SENSOR FOR FOREIGN DEBRIS
1. Remove the CMP sensor and inspect for foreign debris.
Is the CMP sensor free of foreign debris?
-> Yes
Goto <<R3>>
-> No
CLEAN the sensor and wheel. INSTALL the sensor. CLEAR the DTCs. TEST the system for normal operation.

R3: CHECK THE CMP SENSOR SENSE CIRCUIT FOR HIGH RESISTANCE
1. Disconnect the battery negative terminal.
2. Disconnect the CMP sensor electrical connector, PI16.
3. Disconnect the ECM electrical connector, EM83.
4. Measure the resistance between EM83, pin 19 (G) and PI16, pin 01 (G).
Is the resistance greater than 5 ohms?
-> Yes
REPAIR the high resistance circuit. For additional information, refer to the wiring diagrams. CLEAR the DTC. TEST the system for normal operation.
-> No
Goto <<R4>>

R4: CHECK THE CMP SENSOR SENSE CIRCUIT FOR SHORT TO HIGH VOLTAGE
1. Reconnect the battery negative terminal.
2. Turn the ignition switch to the ON position.
3. Measure the voltage between EM83, pin 19 (G) and GROUND.
Is the voltage greater than 3 volts?
-> Yes
REPAIR the short circuit to high voltage. For additional information, refer to the wiring diagrams. CLEAR the DTC. TEST the system for normal operation.
-> No
Goto <<R5>>


R5: CHECK THE CMP SENSOR SENSE CIRCUIT FOR SHORT TO GROUND
1. Turn the ignition switch to the OFF position.
2. Measure the resistance between PI16, pin 01 (G) and GROUND.
Is the resistance less than 10,000 ohms?
-> Yes
REPAIR the short circuit to GROUND. For additional information, refer to the wiring diagrams. CLEAR the DTC. TEST the system for normal operation.
-> No
INSTALL a new CMP sensor. CLEAR the DTC. TEST the system for normal operation.

Jim Lombardi

 

It is important to note that these tests apparently DO NOT test the sensors themselves. The measurements are "looking" back towards the ECM with the sensor unplugged and are wiring checks only. I noticed this when I read the resistance measurement spec for the Knock Sensor was 5 ohms or less. The resistance measurement "looking" towards the knock sensor should be a good bit greater that 20 MEG ohms, as I recall. The other sensors are in the 750 to 1K ohm range.

The only really good way to test the reluctor pickups (the cam and crank sensors) is with a scope, looking for a -1-2 volt or so sorta square wave but an intermittent circuit is very difficult to diagnose. Sensor replacement is probably best if these are suspect. The knock sensors mostly fail when moisture gets into them after the case cracks. Look for micro cracks of the black plastic. Also,in my case, their resistance lowered to a few Meg ohms in my case when they failed. You can put a scope on a KS and tap it with a wrench to make sure it responds, but that obviously does not test calibration level, only operation.

Maybe you could let us know what symptoms led to your diagnosis of an ignition problem... Without the codes "ignition problem" covers a lot of territory and would usually include possibilities of faults from other systems with relayed systems.

 

Ordinary OBD tools should work - what goes wrong? Checked the OBD fuse/wiring?

I don't understand how you know you've codes if the reader doesn't work! MIL on, is that all you know?