P1718 code

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Tezza_1
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Joined: 25 Aug 2021, 15:30

P1718 code

Post by Tezza_1 »

Hi, I've recently had the above code flash up on the dashboard, I've got a Citroen C4 Picasso semi-automatic, 09 plate, drives fine goes through gears fine, occasionally when trying to go into reverse it doesn't want to know. Any advice would be appreciated thanks
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GiveMeABreak
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Re: P1718 code

Post by GiveMeABreak »

Hi and welcome. This fault is to do with the gear selection control or an electrical issue with it:
Fault Code: P1718
Description of Fault: Gear selector signal fault (Lever) : Coherence. Signal from the gear selector sensor incoherent (one or more of the switches on the selector faulty).
Conditions for Fault to clear: No faults for 2 seconds.
Downgrade Modes whilst Fault is active:
  • If the vehicle is moving in forward gear, automatic mode is activated and reverse gear cannot be engaged.
  • Starting possible provided the gearbox is manually in neutral with presses on the brake pedal.
  • Possible to engage the gears via the paddles.
  • Crawling deactivated.
  • If the vehicle has the Stop and Start system: Stop and start function deactivated.
Warning Lamps Displayed:
  • "SERVICE" warning lamp
  • Sport warning lamp
  • Snow warning lamp
  • Automatic or 6-speed piloted manual gearbox warning lamps (Orange PRND triangle)
  • Display of a "-" on the fascia panel
Symptoms:
  • Difficult/impossible to change a gear.
  • Lack of power.
  • Absence of automatic stopping of the internal combustion engine.
Suspect Areas:
  • Piloted manual gearbox ECU.
  • Sealing of the connectors and harnesses.
  • 28-way connector of the piloted manual gearbox ECU.
  • 28-way harness of the piloted manual gearbox ECU.
  • Gear lever.
  • Gearbox ECU.
  • Earth cable.
  • Earth screw.

So has any work been done lately that could have impacted on the electrical connections of the gearbox selection controls or any wiring modifications or aftermarket equipment added?
Tezza_1
Posts: 5
Joined: 25 Aug 2021, 15:30

Re: P1718 code

Post by Tezza_1 »

Hi Marc, thanks for getting back to me, other than having 2 new drive sensors put on by my mechanic at a local garage then no. It only came up a few days ago. We did a diagnostic check and that's the code that came up , tezza
Tezza_1
Posts: 5
Joined: 25 Aug 2021, 15:30

Re: P1718 code

Post by Tezza_1 »

Hi Marc, other than having 2 new drive sensors put in then no, this came up a few days ago and when we did the diagnostic check it gave the code p1718 with a msg, gear lever signal fault,
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GiveMeABreak
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Re: P1718 code

Post by GiveMeABreak »

I'm not sure I understand what you mean by 'Drive Sensors' - can you explain what these are....
Tezza_1
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Joined: 25 Aug 2021, 15:30

Re: P1718 code

Post by Tezza_1 »

The drive sensors are located under the front wheels
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GiveMeABreak
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Re: P1718 code

Post by GiveMeABreak »

Ok, some terminology confusion - I think you are referring to the wheel speed sensors used by the ABS / ESP system for various functions - including supplying the piloted gearbox with information.

I would check that any connections have not been disturbed on the piloted gearbox ECU as these could easily have been moved during the recent work on the wheel speed sensors - but obviously some further investigation is needed. The first checks should always be the electrical plugs and connections on the piloted gearbox ECU and earths.
Tezza_1
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Joined: 25 Aug 2021, 15:30

Re: P1718 code

Post by Tezza_1 »

Hi Marc, that's great thank you I'll check that out and see how it goes