Mechanics

THROTTLE POSITION SENSOR

2000 Jaguar Vanden Plas

Engine Mechanical problem
2000 Jaguar Vanden Plas V8 Two Wheel Drive Automatic 71000 miles

Yesterday I had submitted a question regarding the codes that came up on my 2000 Jaguar Vanden Plas with the engine warning light and traction control failure and ABS failure

Specifically P0121, P1251, P1647, P1657.

A local garage quoted me $3400 to replace the throttle body assembly and the left front oxygen sensor.

You had advised me to check the TPS. However, after researching in the year 2000 Vanden Plas, there appears to be no TPS replacement part. Ive found this part only through years 1987 for the Vanden Plas. Any suggestions other than having to order a new throttle body?
Avatar
Elisa404
October 19, 2010.




Hello and thanks for donating

Upon researching this information I have found that there is indeed no replacement for the TPS alone. The TPS is actually functioned as part of the throttle body assembly itself. Sadly but true, to replace the TPS. The whole assembly must be replaced.

Bluelightnin6
Oct 19, 2010.
Thank you for clearing that up. If you would look at the other codes to see if there are any other smaller items I need to check before such a big repair I would appreciate it. I know that replacing the TPS was a quick less costly fix that a memeber suggested. The codes are
P1642 Vehicle Speed Output Circuit
P1111 System Pass
P1251 Throttle Position
P1642 CAN Link Circuit
P1637 CAN Link ECM/ABS Control Module Circuit/Network
P1657 Throttle Motor Power Relay Coil Circuit On Failure
P1251 Throttle Position
Or
Throttle Motor Power Relay Malfunction (another site)

P0121 Throttle Position Sensor Circuit Range/Performance

P1647 heated upstreme oxygen sensor
OR
P1647 Linear O2 Sensor Control Chip (Bank 2) from another site.

P1657 saying throttle motor driver relay

The car is driving so well with no problems at all until out of the blue one crank results in a FAIL SAFE engine code. Also, in your opinion is there any reason to replace the O2 sensor? I've read this is a common misread code. Are there any fuses/ relays etc. Worth checking. Again thank you. I need to re-donate : )

Tiny
Elisa404
Oct 19, 2010.
Did all of these codes pop up at once? Was the check engine light on at all prior to this? If they did all come up at once I would not be surpised if this was a faulty engine control module (ECM) causing these issues. As a matter of fact, truely the only thing that should cause code 1657 would be a faulty ECM. As for the oxygen sensor(s), they are actually considered to be a regular maintenance item just like replacing engine oil etc.
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Bluelightnin6
Oct 19, 2010.
Actually,
P1642 Vehicle Speed Output Circuit
P1111 System Pass
P1251 Throttle Position
P1642 CAN Link Circuit
P1637 CAN Link ECM/ABS Control Module Circuit/Network

Came up at Advanced Auto and

The following are the codes with the shops description
P1647 heated upstream oxygen sensor
P1657 Throttle Motor Driver Relay
P1251 TPS
P0121 TPS sensor A
Came up at a shop that specializes in Jaguar. I should note my first posting as to my experience with this shop.

Tiny
Elisa404
Oct 20, 2010.
My money lies with a faulty engine control module (ECM). I don't see a faulty TB causing all of these codes, and like I said the ONLY possible cause for the 1657 is indeed a faulty ECM.

Bluelightnin6
Oct 20, 2010.
Thank you, finally are there any ideas on the most economic way to get this replaced? Is a salvage yard an option?

Again, thank you. You are definately the most knowledgeable of anyone we have asked for advice.

Tiny
Elisa404
Oct 21, 2010.
Replacing it with a used module is certainly an option, it does require a scan tool to perform a few setups though so you will probably need a repair shop to do that for you. The ECM itself is located at the right rear side of the engine compartment, in the control module enclosure. I have the location highlighted in the diagram.


http://www.2carpros.com/forum/automotive_pictures/261618_Noname_2813.jpg


Bluelightnin6
Oct 21, 2010.
After bringing my 2000 Vanden Plas to a local mechanic, the failsafe engine warning and traction control failure warnings would shut off upon disconnecting he Throttle Body Sensor plug and then plugging back in. Could this possibly still be an ECM-related issue? Or is it more likely the Throttle Body itself?

If I need a new Throttle Body, can you recommend where to find one at a discount?

Thanks

Tiny
Elisa404
Oct 25, 2010.

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