Peugeot 307 AL4 and ABS crazy on faults and car speed. 655Km/h

[phophollety]

Hello Mates,

I own a 2007 307 2.0 fitted with AL4 transmission.

Few days ago I was at traffic and suddenly got an ABS fault, light on dash and screen. This bizarre fault putted the AL4 transmission in emergency mode, engaging the 3rd gear, but after 40KM/h or so it disengage the 3rd and I can switch the gears through manual normally, but as soon as I stop the transmission engages the 3rd once again.

My transmission has a old problem of low launching torque. If I press the gas pedal all the way while the car is stopped (break fully depressed) the rpm won't go beyond 1500rpm, but you feel the engine giving all torque possibly, the oxygen sensor shows rich, the fuel injector goes > 90% and the buttlerfly valve fully opens but the car has very very low torque. I have being avoiding climbing hills through traffic.

Well, back to ABS. It show failure on the front left sensor C1320 Front LH wheel speed sensor signal fault but if the car ins moving all wheels shows the same speed and the speedometer works fine. I can clear this fault but it returns.

The AL4 Transmission gets U1313 Vehicle speed transmitted by the ABS fault. The crazy part is the fault logs engine RPM @ 8160rpm (never went there haha). The parametes measurements shows speed of 655Km/h while the vehicle is stopped and engine is off. Totally crazy.

I've replaced my battery, its was 3 years old and showing signs of wear.

I've removed engine and transmission ECU, BSI and PSF for electrical connectors inspection: all clear! All fuses are good, checked twice!

Well, I'm totally lost, any help is very appreciated.

[hhp]

Check the wheel speed sensor, which shows measurement data 655 km / h

[phophollety]

Check the wheel speed sensor, which shows measurement data 655 km / h

I've not yet removed the ABS Sensor (crowded garage yet). Engine is stopped, transmission in P. At ABS diag all speed sensors are 0, as well the ABS output speed 0. The speed on dash is 0. The speed on fuel injection diag is 0. The speed on transmission diag is 655km/h! Totally crazy!

Have not yet driven the car on street while watch transmission diag. I can acess the ECU normally through diag, all modules show up fine on global test.

BSI and PSF sometimes has failures of "mute on can" but the always had this faults since I got this car. My front fog lamps are removed and also got this fault on PSF, but I cat see no relation at all!

Here are all faults dialog. The AL4 thinks engine is running at 8000rpm when logged the fault

https://drive.google.com/drive/u/0/folders/0BxlZ1VzjFIjmSEM1dndIRElDaWM

[phophollety]

Up, please any tips are appreciated

[sjsephy91]

check whether the wiring is good from the sensor to the ABS, you can also try to change the PSF for test .. But I would have replaced the sensor and check the wiring ..

[phophollety]

Today I could disassemble the left wheel, the left sensor was open on resistance check, the right side shows 560K ohms, is that high??

Moving the cable around, it closes the circuit back to 560K in some points. Will order a new one tomorrow.

But can't stop thinking how stupid is this failure mode, put the transmission in this crazy situation just because ONE ABS sensor? OK, just disable the ABS but the unit has 3 more sensors to measure the vehicle speed.

What did that guys had in mind??

I'll let you know for the fix.

[phophollety]

Found the left ABS sensor with broken cable. The cable makes a little curve between the shock and the caliper. Measuring the good sensor (right wheel) the resistance was about 560K. Right side was open. Ordered the new sensors monday, installed yestearday. All working fine, neither had to clear the previous fault for everything work properly =D

[sjsephy91]

Yes, that's it ... speed 655 km / h, is a symptom of bad wiring or dead sensor ..

I'm glad you made it, salute! :D

[hhp]

I have the solution you wrote above, you could save a lot of time ....