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Nexon Gasoline – EMS ECU Bosch
DTC Troubleshooting Manual
Version: 0.1
Date: 26-08-2017
Prepared By: Sunu S Babu/Yogesh Jadhav
Checked By: Yeshwant Jadhav
Approved By: Satish Kumar
Document Part No: 2921 02 224 A1736
Page: 637 of 1203
Copyright ©
TATA MOTORS Ltd.
This document must not be used in any way, such as copying and redistributing to third parties, without the consent of author.
P0500-84: Vehicle Speed Sensor “A”– Signal Below Allowable Range
Overview:
ISO Code
P0500-84
Customer Symptom
Cluster might display incorrect vehicle speed.
Driveability will be bad
Fault Effects (On Vehicle)
Cluster might display incorrect vehicle speed.
Driveability will be bad
Lamp Status (If Any)
CE Lamp ON after 3 drive cycle
Fault Detection Condition
This Fault gets logged if the Vehicle speed signal sent by Instrument cluster
to EMS ecu on CAN is Implausible or not available.
Normal Operating Condition
Plausible Vehicle speed signal available to EMS
Probable Trouble Area
CAN bus, Faulty Vehicle speed Sensor, Improper Interface between
Instrument Cluster and Vehicle speed Sensor or, Improper Interface between
ABS and wheel speed Sensors?
Healing Condition
Vehicle running and after 1 drive cycle of fault rectification
Fault permanent deletion
1. Clear DTC Command form Scan tool
2. Stack Over Flow.
3. 40 warm up cycles.
4.ECU flashing
5. ECU Power-Fail
Component Details:
A typical Hall Effect Sensor has three wires or terminals: one for ground, one for supply or reference voltage and one
for the output signal. To produce an output signal, a Hall Effect Sensor must be supplied with a reference voltage.
When a metal/wheel passes through the air gap between the magnetic field (Magnet) and silicon chip, it blocks the
magnetic field and causes the chip’s output voltage to suddenly drop to zero else the chip's output voltage is 4.7 Volts.
So, it produces a near square wave/ pulses, which will be counted and vehicle speed is calculated.
Preliminary Checks:
1. Check whether the CAN Bus is Functional.
2. Check for any Vehicle Speed Sensor related faults in Instrument Cluster ECU or ABS.
3. Check for proper wiring Harness connections between CAN bus and EMS ecu.
4. Check for any pin back out at EMS ecu connector