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First of all, please tell us the year, model and engine of your Jaguar.
Secondly, as Jeff asks, do you know what diagnostic fault codes (DTCs) the shop found that prompted them to suggest a new battery and MAFS? Does the shop have a diagnostic system capable of reading proprietary Jaguar codes? I ask because standard OBDII scanners can only read the Powertrain (P-prefix) codes, but codes that can cause Traction Control and Automatic Stability Control to be disabled are often Chassis (C-prefix), Body (B-prefix) and Network (U-prefix) codes.
If you will post all the codes here and we'll do our best to help.
See page 101 :Blue wire 0.50 volts DC at idle going toward 5.0 on throttle up . The Green wire should read the same as a comparison as there are 2 TPSs on the same connector .
No need to run the engine just key on before start and twist the throttle for single person operation
First of all, please tell us the year, model and engine of your Jaguar.
Secondly, as Jeff asks, do you know what diagnostic fault codes (DTCs) the shop found that prompted them to suggest a new battery and MAFS? Does the shop have a diagnostic system capable of reading proprietary Jaguar codes? I ask because standard OBDII scanners can only read the Powertrain (P-prefix) codes, but codes that can cause Traction Control and Automatic Stability Control to be disabled are often Chassis (C-prefix), Body (B-prefix) and Network (U-prefix) codes.
If you will post all the codes here and we'll do our best to help.
What you don't want to see on the TPSs is a reading going to zero volts as you slowly move the throttle though it's range as this would indicate a open spot on the wiper brush on the resistance coil inside the TPS .
Just for kicks, try turning on the ignition fully without starting the engine and then depress the accelerator through its full range 30 or 40 times.
Maybe there is a corrosion spot in the TPS?
See if doing that improves anything. If it doesn’t work at least it didn’t cost anything to try. If it does improve things then it points to your problem.
Yep , Nailed it with that suggestion with the exception of effects of vibration and heat effects which is not accounted for , including in my suggestion .
You can read the codes for free at the auto parts store with the exception of the ABS / TC . Be sure to have them reset the codes to see it they reappear latter in the week .
Last edited by Lady Penelope; Mar 29, 2018 at 11:32 AM.
Don't believe the MAF will give you Failsafe -- will give you the CEL. How is it running?
Do exercise the pedal to clean the sensor ... best to invest the $30 bucks for a simple code reader. It can sometimes take a few times to get all the codes cleared -- it's a strange OB system.
It could be a bad MAF ... hear of them failing. Have owned 100's of cars in the past 20 years -- have never had to replace one. I own a business with many vehicles.
I would install battery/ clear all codes and see what comes back first
Urgent,help!Failsafe engine mode, traction ,ASC
