DTC Advanced Diagnostics: P1855
DTC P1855 : Inclination Sensor Circuit Range/Performance
General Description
The G sensor is built into the SRS unit. The G sensor detects the road gradient at the time of vehicle stop and outputs information to the transmission control module (TCM). The TCM uses the G sensor output received by F-CAN lines for vehicle creeping torque switching. If the G sensor output voltage is less changed during the condition there is a forward and backward acceleration, the TCM detects a malfunction and stores a DTC.
Monitor Execution, Sequence, Duration, DTC Type
| Execution | Continuous |
| Sequence | None |
| Duration | Depending on the driving conditions |
| DTC Type | Two drive cycles, MIL off, Shift position indicator off |
Enable Conditions
| Condition | Minimum | Maximum | |
|---|---|---|---|
| Engine speed [Engine Speed] | 500 rpm | - | |
| Difference of front wheel right-and-left average speed and rear wheel right-and-left average speed | - | 3 mph (5 km/h) | |
| Shift position/mode | D, S | ||
[ ]: HDS Parameter
Malfunction Threshold
The G sensor output voltage change width is less than 0.03 V after the vehicle is driven at following conditions:
- Drive the vehicle at accelerator pedal position 1/16 or more and vehicle speed [Vehicle Speed] more than 4 mph (5 km/h) for at least 1 second.
- Reach the vehicle speed [Vehicle Speed] to 14 mph (21 km/h) or more.
- Decelerate to more than 4 mph (5 km/h) with throttle fully closed for at least 1 second.
- Stop the vehicle.
Possible Cause
The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.
- SRS unit internal failure (G sensor)
Confirmation Procedure
Operating Condition
- Start the engine.
- With the brake pedal pressed, place the shift in D position/mode.
- Drive the vehicle at a speed of 14 mph (21 km/h) or more. (Accelerate for at least 1 second.)
- Release the accelerator pedal, and slow down the vehicle. (Take at least 1 second to decelerate to more than 4 mph (5 km/h).)
- Turn the vehicle to the OFF (LOCK) mode.
- Repeat Driving Pattern steps 1 through 4.
- Drive the vehicle in this manner only if the traffic regulations and ambient conditions allow.
Diagnosis Details
Conditions for setting the DTC
When a malfunction is detected during the first drive cycle, a Pending DTC is stored in the TCM memory. If the malfunction returns in the next (second) drive cycle, a Confirmed DTC and the freeze data are stored. The MIL does not come on and the shift position indicator does not blink.
Conditions for clearing the DTC
The Pending DTC, the Confirmed DTC, and the freeze data can be cleared with the scan tool clear command.