My cheat sheet lists 1718 as an open or short in the fluid pressure sensor cct so I'd be pulling and cleaning connectors and attempting a reset via techstream as a first pass attempt. The book says check sensor, sensor cct then ECU. Pulling AHC IG 20A fuze for 20 minutes or so (drivers foot well, firewall end of the fuze block for an 03 LHD) may help. I suspect you're not going to be able to progress fault finding and definitively rule in or rule out failed globes until you can get the system out of fail safe. Also try and get front neutral pressure back to 6.9MPa and rear within that 5.6 to 6.7 range. If you have had one or both rear accumulators fail you would have seen a significant drop in the fluid's reservoir level, and it has very little excess capacity between its high and low fluid marks, and the charge(s) (nitrogen I guess) would be entrained in the system too unless it has been properly bled. For the main accumulator I get readings around 10.4 or so.laptop back and semi-functional… DTC code C1718 present for the Pressure Sensor Circuit. Found this below elsewhere on this board (format is poor):
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CIRCUIT INSPECTION
CIRCUIT DESCRIPTION
DI3GI−06
DTC
C1718 / 18
Fluid Pressure Sensor Circuit
This circuit is sending the data to detect the pressure output from the pump and to judge the abnormality of the fluid pressure by the ECU.
DTC Detecting Condition:
Either of the following 1. or 2. is detected:
1. When detecting the abnormal signal from the fluid pressure
sensor (Fluid pressure sensor terminal voltage of ECU is 0.3 V or less or 4.7 V or more) for every 0.01 sec. and that condition continued for 1 sec.
2. While the motor relay is non−operating, the condition that the fluid pressure exceeds 1 MPa (10.2 kg/cm2, 145 psi) continued for 10 secs.
Trouble Area:
- Fluid pressure sensor
- Fluid pressure sensor circuit
- Suspension control ECU
Fail safe function:
If trouble occurs in the fluid pressure sensor circuit, the height control is prohibited after the ECU has adjusted the vehicle height to the standard.
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Suggestions where to go from here? I don't want to throw money at the problem and just start replacing things if I can further zero in on the problem. This is the first time I've dealt in anywhere near this kind of detail with Toyota codes and manuals (just got Techstream) and have more information than I know how to use.
BTW - my neutral pressures are a little high as well - 7.7 or 7.8 F and R. I'm going to try to fix the front this weekend with the torsion bars, but will have to wait on the rear and take it someplace that can install spacers or refresh the springs.
What is spec on the accumulator pressure?
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