Coolant Temperature Gauge Circuit Test
- Test coolant temperature sending unit. See COOLANT TEMPERATURE SENDING UNIT
under COMPONENT TESTS. If coolant temperature sending unit is okay, go to next step. If coolant temperature sending unit is defective, replace coolant temperature sending unit.
- Disconnect instrument cluster 24-pin harness connector M33. Disconnect coolant temperature sending unit harness connector. Measure resistance in Purple/White wire between instrument cluster harness connector M33 terminal No. 18 and coolant temperature sensor harness connector. See Figure
. If resistance is 5 ohms or less, go to next step. If resistance is greater than 5 ohms, repair open or shorted condition in Purple/White wire.
- Check continuity between ground and instrument cluster harness connector M33 terminal No. 18 (Purple/White wire). If continuity exists, repair short to ground in Purple/White wire. If continuity does not exist, go to next step.
- Connect combination meter and ECM harness connectors. Start engine. Using an oscilloscope or CONSULT-II, check the output signal in the Purple/White wire between combination meter M33 terminal No. 18 (Purple/White wire) and ground. If using CONSULT-II, use "SIMPLE OSCILLOSCOPE" in "SUB MODE". If the signal is as shown in Fig 1
, replace the combination meter assembly. If the signal is not as shown in Fig 1
, check the ECM. See SELF-DIAGNOSTICS
article in ENGINE PERFORMANCE.
Courtesy of NISSAN MOTOR CO., U.S.A.