TATA PUNCH-SERVICE MANUAL

1.2L REVOTRON ENGINE 155  Preliminary Checks : 1. Loose/ Damaged Connections between Sensor and EMS ECU. 2. Check for back out of pins at both Sensor connector and ECU connector. 3. Check for damage of pins at both sensor connector and ECU connector. 4. Check the continuity from sensor connector pins to the ECU pins. 5. Check for Sensor poisoning /  Connector View :  Connector Details : Connector Description Upstream Downstream 1 Supply Supply 2 Ground Heater 3 Heater Ground 4 Signal Signal  Component Specification : The lambda sensor is mounted on the closed couple catcon. The lambda sensor has a four pin connector with a special ceramic body and gas permeable platinum electrodes on the surface. When the ceramic body is exposed to temperature 350 0 C, oxygen in the air diffuses into ceramic body. Depending on the porosity electrodes which are exposed to gas having varied level of oxygen. The lambda sensor provides air/fuel ratio signal in mili volts to ECU as a function of varying air/fuel ratio. At 350 0 C, Lambda = 0.97 - 800 mV ± 55 mV(Rich mixture) Lambda = 1.1 - 50 mV ± 30 mV (Lean mixture)  Sensor Stand alone Diagnosis : Connector details Use TATA diagnosis tool to check for : Signal voltage - > than 0.5V or < than 0.4V Switching frequency - > than 0.2 Hz Use multimeter to check the heater function by measuring the heater resistance. Heater resistance at room temperature – 90 ohms Supply voltage – 12V DC Check the signal voltage (Between pin number 2 and 3) Signal Voltage - 0.68 ± 0.25V DC- at idle position Signal Voltage - 04.25 ± 0.45V DC – at WOT position