I've just bought an XFRS from auction and I'm having some troubles with it.

I have the problem of losing power momentarily when increasing the RPMs quickly to get to motorway speed.

Then at a roundabout, I wanted to make a quick dash in and out, so opened the throttle quickly, and, "Restricted Performance" mode. This has happened 3 times now since I've had the car for 3 weeks.

I had the laptop and cable in the car, so very very very (max 20km/h) made my way to a safe spot and looked at the data:

• P0122-00 - PCM - Throttle/pedal position sensor A - circuit low input --- Sensor 1 circuit short to ground, open circuit. Sensor 1 failure.
• P0222-00 - PCM - Throttle/pedal position sensor B - circuit low input --- Sensor/switch B circuit open circuit, short to ground. Sensor/switch failure.
• P0237-00 - PCM - Turbo/supercharger boost sensor A - circuit low --- Sensor short to ground, open circuit, high resistance. Sensor 2 failure.
• P0341-00 - PCM - Camshaft position sensor A - circuit range/performance (bank 1 or single sensor) --- Sensor short to ground, short to power, high resistance, disconnected. Sensor gap incorrect, foreign matter on sensor face, damanged rotor. Sensor failure.
• P2127-00 - PCM - Throttle/pedal position sensor/switch E circuit low input --- Short circuit to ground, open circuit. Circuit reference VREF Open circuit. Failure.
• P2135-00 - PCM - Throttle/pedal position sensor/switch A/B voltage correlation --- Sensor circuit 1 and 2 short to ground, short to power, open circuit.
• U0401-64 - TCM - Invalid data received from engine control module/powertrain control module.

Car restarts and I can drive away normally again. Just going very smoothly on the throttle.

Previously when this happened I had the codes:
1. P0122-00: Tpa circuit low input
2. P0222-00: Throttle/pedal position sensor/switch b circuit low input
3. P2135-00: Throttle/pedal position sensor/switch a/b voltage correlation
4. P2092-00: Camshaft position actuator A - control circuit low, bank 2
5. P0341-00: Camshaft position sensor circuit range/performance
6. P0343-00: Camshaft position sensor A - circuit high (bank 1 or single sensor)
7. P0368-00: Camshaft position sensor B circuit high (bank 1)

What I've done:

• Checked the BCM(a)/CJB, BCM(b)/AJB. No evidence of any moisture ingress
• Replaced the dying main and auxiliary battery with new ones
• Checked all fuse boxes for any blown fuses (there were none)
• Reset the immobilisation and ran the new battery program on SDD, after changing the battery
• Checked the main positive cable that goes underneath the driver's wheel arch in the engine bay for any corrosion, none, looks like new
• Ruled out flood damage
• Checked the earths in the driver's wheel arch, boot, and behind the instrument cluster
• Cleaned out sensors for MAF, throttle body, and accelerator

Any thoughts as to what my issue is?

 

you have a bad reference voltage line. since it’s intermittent it is it’s probably rubbing on something or one of the components it’s pulling the ref down

 

Alright, so I spent the whole day with the car, doing some diagnostics, also took out the plugs for the accelerator pedal, gave them a good clean and reseated. The sensor data all looks okay. Also did the MAF plugs, because they're easy.



Then a really long drive the entire afternoon for 120km 75mi. And. Nothing.....
No faults, no codes, no restricted performance. Just good vibes.
Although I was very gentle and smooth with the throttle the entire time, I didn't push the car hard.

I thought I felt a little bit of that loss in acceleration on a quicker throttle again, but it actually feels like it might be the gearbox, or something in the rear, almost like it was holding the gear too long (revs weren't super high) and the power peters out. Once the gear changed happened I got power back. Is this normal??

I'm hoping it will keep this way if I just drive gently. I think it's due for a big engine checkup though, so at some point probably in the new year, I'm thinking of getting the timing chain done, super charger refreshed, coolant pipes redone, upper and lower pulleys, new solid coupler, and spark plugs. I plan on taking this to Europe and doing some tracks, so I want it in good shape.

Thanks for the help so far!

 

Just to update this, after a good couple weeks and 1,000km/620mi + of driving, it appears I've been able to resolve a lot of the issues Iv'e been having (part for 1 recurring fault which I know how to fix now). All I did was get down under the dash, pull the plugs from the accelerator pedal, the CJB/BCMa, and behind the instrument cluster. I gave them all a nice clean out with contact cleaner, and resat them making sure they were all nice and tight. I also made sure the two earths behind the instrument cluster were properly seated by undoing them, spraying with oil, and tighening again.