NEXON DIAGNOSTIC MANUAL

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: 1066 of 1203

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.

P2279-7A: Manifold Leakage Detection – Fluid Leak or Seal Failure

Overview:

ISO Code

P2279-7A

Customer Symptom

High Engine Idle RPM, Exhaust and catalyst heat up, Over heating of the engine.

Fault Effects (On

Vehicle)

Calculated Secondary Charge (Based on Throttle angle and Engine speed) will

drive the engine.

Lamp Status (If Any)

MIL ON after 3 drive cycles

Fault Detection Condition This fault gets logged if the TMAP Sensor Pressure signal is implausible with

respect to Engine Operating Condition.

Normal Operating

Condition

TMAP Sensor Pressure signal is plausible with respect to the Engine operating

condition

Probable Trouble Area

Wiring Harness Connections, Inlet Air Circuit Clogging / Damage, TMAP Sensor,

Boost Pressure Sensor, Throttle Actuator stuck closed, Boost / Turbo Actuator /

Waste gate stuck closed / Open.

Healing Condition

Engine Running and after 3 Driving Cycles

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:

TMAPSensor consists of a silicon chip mounted inside a reference chamber. On one side of the chip is the reference

chamber and on the other side is the pressure to be measured. The electrical resistance of the chip varies with the

variation of pressure. This change in resistance alters the voltage signal. ECM interprets the voltage signal as

pressure and any change in voltage signal as change in pressure. The temperature Sensor element is a NTC resistor.

Preliminary Checks:

1. Inlet Air Circuit Clogging.

2. Loose/ Damaged Connections between Sensor and EMS ECU.

3. Check for back out of pins at both Sensor connector and ECU connector.

4. Check for damage of pins at both Sensor connector and ECU connector.