Automatic Gear Box issues

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GAZZEH
Donor 2021
Posts: 3
Joined: 17 Dec 2021, 10:15
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Automatic Gear Box issues

Post by GAZZEH »

Dear All,
(Please Richard, I need your help, along with the other members)
I'm a new member who found the forum after an online search.
If you can help, please be patient with my post, as I'm not specialized.
My issue:
When moving the automatic gear lever from P to R, from P to N, and from P to D, the car "literally jumps". This has been happening for months, and I realized that my engine mounting was damaged because of that (in part).
Replaced the 3 engine mountings: left, middle, and under the battery (view facing the engine bay and the windshield).
No change, the car still "jumping" when moving the lever from P to R, from P to N, and from P to D.

The display of the speeds are correct (when in D, it displays D, etc.).
A local garage has run a diagbox diagnostics and a very long list of trouble codes appears with 2 of them about the gearbox:
- U1308 00 - Control unit "gearbox" : Communication error between the automatic gearbox and the engine management distant (old code at 58289 km - current distance 85754 km)
- U1209 00 - Control unit "ABS/traction control": absence of communication with the automatic gearbox ECU distant (old code at 58641 km - current distance 85754 km)
- P0717 00 - Control unit "gearbox": gearbox input engine speed signal fault. local (New code at 82575 km - current distance 85754 km)
I have replaced the input engine speed sensor but no changes, my issue is still there (car "literally jumping").

This is the list of trouble codes, if it can help experienced members to figure out the reasons behind.
Citroën C4 - Model year 2012 - Automatic 4-speed gearbox.
1.6 VTi 16v 120 (B7)
Engine type EP6C
85754 km
Thank you for your time.
Last edited by GiveMeABreak on 17 Dec 2021, 11:38, edited 1 time in total.
Reason: Moved to the Citroen Technical Forum
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GiveMeABreak
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Re: Automatic Gear Box issues

Post by GiveMeABreak »

Hi and welcome (and thank you for your recent donation).

Please pop your VIN up for us (Automasked on post submission) so we can determine exact vehicle options / specifics and relate fault codes to the correct ECUs.
GAZZEH
Donor 2021
Posts: 3
Joined: 17 Dec 2021, 10:15
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Re: Automatic Gear Box issues

Post by GAZZEH »

Many thanks Marc
This is the VIN: VF7**************[VIN obfuscated, can be read by forum staff]
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GiveMeABreak
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Re: Automatic Gear Box issues

Post by GiveMeABreak »

Ok, so this is with the AL4 gearbox. These are the fault code descriptors for you - it should help give you some pointers. Note the subsequent 'Possibility' indicator responses relate directly to the original possibility numbers 1-5 in the Fault Description Section.
Fault Code: U1308
Description of Fault: Fault in communication between the automatic gearbox (BVA) and the engine management (ECM): Values received incorrect or invalid.

Possibility 1
- Accelerator pedal position value not valid
- Fault confirmation time: 1s
Possibility 2
- The engine speed value is invalid
- Fault confirmation time: 1s
Possibility 3
- Invalid cooling temperature information
- Fault confirmation time: 2s
Possibility 4
- Invalid actual engine torque information
- Fault confirmation time: 1s
Possibility 5
- Detection of an invalid value on one of the internal torques of the engine ECU
- Fault confirmation time: 1s
Conditions for Activation of Fault: Possibility 1, 3, 5
The following conditions have to be met
- Engine running
- Battery voltage between 10,5 and 16 V
Check that there are no fault codes
- U1003 (CAN communication fault (Missing/interference): No signal)
- U1108 (Fault in communication between the automatic gearbox (BVA) and the engine management (ECM): No signal)[

Possibility 2
The following conditions have to be met
- Engine running
- Battery voltage between 10,5 and 16 V
Check that there are no fault codes
- U1003 (CAN communication fault (Missing/interference) : No signal)
- U1108 (Fault in communication between the automatic gearbox (BVA) and the engine management (ECM) : No signal)
- Engine speed information invalid

Possibility 4
The following conditions have to be met
- Engine running
- Battery voltage between 10,5 and 16 V
Check that there are no fault codes
- U1003 (CAN communication fault (Missing/interference) : No signal)
- U1108 (Fault in communication between the automatic gearbox (BVA) and the engine management (ECM) : No signal)
- Invalid actual engine torque information/td]
Conditions for Fault to clear: Possibility 1
The accelerator pedal position signal is correct
Possibility 2
Engine speed information valid
Possibility 3
Invalid cooling temperature information
Possibility 4
Valid actual torque information
Possibility 5
Values of the valid internal torques in the engine ECU
Time of disappearance of the fault: 3 s
Downgrade Modes whilst Fault is active: Possibility 1
At least one of the following downgrade modes is present
- Emergency mode possible; Pedal position forced to a default value; No kickdown
- Pedal position forced to a value that can be calibrated

Possibility 2
Presence of sequence electrovalve fault codes
- P1592 (Electrovalves and regulators supply fault : Open circuit)
- P1593 (Electrovalves and regulators supply fault : Short circuit to positive)
- P0753 (Sequence solenoid valve 1 (SSV 1) output fault : Short circuit between 2 wires or open circuit or short circuit to positive)
- P0758 (Sequence solenoid valve 2 (SSV 2) output fault : Open circuit or short circuit to the plus)
- P0763 (Sequence solenoid valve 3 (SSV 3) output fault : Open circuit or short circuit to the plus)
- P0768 (Sequence solenoid valve 4 (SSV 4) output fault : Short circuit between 2 wires or open circuit or short circuit to positive)
- P0773 (Sequence solenoid valve 5 (SSV 5) output fault : Open circuit or short circuit to the plus)
- P1747 (Sequence solenoid valve 6 (SSV 6) output fault : Open circuit or short circuit to the plus)
- Absence of pressure regulation
- No lock-up control
- Absence of control of Neutral when cold (No engine starting assistance in low temperatures)
- Control of the solenoid valve controlling the flow into the exchanger according to turbine speed
Emergency mode possible whether or not any fault codes are present
- P0715 (Gearbox input speed signal fault : Not characterised)
- P0717 (Gearbox input speed signal fault : No signal)
- P0720 (Gearbox output engine speed signal fault : Not characterised)
- P0721 (Vehicle speed data fault : Coherence)
- P0722 (Gearbox output engine speed signal fault : No signal)

Possibility 3
- Coolant temperature = The oil temperature
- Absence of emission control mode : The driving mode is the "autoadaptive gear change laws" driving mode

Possibility 4
-

Possibility 5
Emergency mode possible
Symptoms:
  • Lack of power
  • Hesitation
  • Deactivation of the cruise control
  • Deactivation of the speed limiter
  • Difficult/impossible to change a gear
Suspect Areas:Engine management ECU

Fault Code: U1209
Description of Fault: Fault in the "Gear Engaged" information received from the Automatic gearbox or controlled manual gearbox: Value not valid. Data received invalid.
Triggered with engine running.
Conditions for Fault to clear: The following conditions have to be met:
  • Return of a valid value
  • Passing of the steering wheel through point 0.
Downgrade Modes whilst Fault is active: Directional headlamp not operational.

Warnings / Messages:
  • Displaying of an error message for the directional headlamps or the automatic headlamp adjustment
  • Flashing of the dipped beam indicator
  • Audible warning
Symptoms:
  • Directional headlamp not operational
  • The dipped headlamps are constantly straight ahead
  • Flashing of the dipped beam indicator
  • Audible warning
Suspect Areas: Fault in the information coming from the ECU concerned by the fault

Fault Code: P0717
Description of Fault: Gearbox input speed signal fault : No signal. Detection of absence of signal from the turbine speed sensor. Detection threshold: Absence of signal from the turbine speed sensor.
Fault confirmation time: 3s.

Fault Activation Conditions
The following conditions have to be met:
  • Engine running
  • Battery voltage between 10,5 and 16 V
  • Supply voltage provided by the alternator correct
Conditions for Fault to clear: Presence of a signal coming from the turbine speed sensor.
Time of disappearance of the fault: 3 s
Downgrade Modes whilst Fault is active: Lock-up impossible.
Driveability downgraded.

Refuge mode: Gear locked in 3rd
If there are fault codes
- U1308 (Fault in communication between the automatic gearbox (BVA) and the engine management (ECM) : Values received incorrect or invalid)
- P0720 (Gearbox output engine speed signal fault: Not characterised)
- P0721 (Vehicle speed data fault: Coherence)
- P0722 (Gearbox output engine speed signal fault: No signal)

No detection of wheel locking

Line pressure forced to 21 bars if there are fault codes:
- P0705 (Multifunction switch signal fault - Unstable position: Not characterised)
- P0706 (Multifunction switch signal fault - Inconsistent position: Not characterised)
- P0709 (Multifunction switch signal fault - Intermediate position: Not characterised)

Presence of sequence electrovalve fault codes:
- P1592 (Fault: electrovalves and regulators supply: Open circuit)
- P1593 (Fault: electrovalves and regulators supply: Short circuit to positive)
- P0753 (Sequence solenoid valve 1 (SSV 1) output fault: Short circuit between 2 wires or open circuit or short circuit to positive)
- P0758 (Sequence solenoid valve 2 (SSV 2) output fault: Open circuit or short circuit to the plus)
- P0763 (Sequence solenoid valve 3 (SSV 3) output fault: Open circuit or short circuit to the plus)
- P0768 (Sequence solenoid valve 4 (SSV 4) output fault: Open circuit or short circuit to the plus)
- P0773 (Sequence solenoid valve 5 (SSV 5) output fault: Open circuit or short circuit to the plus)
- P1747 (Sequence solenoid valve 6 (SSV 6) output fault: Open circuit or short circuit to the plus)
Symptoms:
  • Lack of power
  • Deactivation of the speed limiter
  • Deactivation of the cruise control
  • Difficult/impossible to change a gear
Suspect Areas:
  • Automatic gearbox ECU
  • Main harness
  • Input speed sensor
GAZZEH
Donor 2021
Posts: 3
Joined: 17 Dec 2021, 10:15
x 1

Re: Automatic Gear Box issues

Post by GAZZEH »

Really, truly appreciate your valuable help.
I will go through these different possibilities and proceed by "elimination" to narrow down their number.
Thank you.