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Home >> Buick >> 1996 >> Roadmaster Base >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control Systems - Tests W/Codes >> Diagnostic Trouble Codes >> DTC P0125 - ECT Excessive Time To Reach Closed Loop >> Diagnostic Aids
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Diagnostic Aids

Using FREEZE FRAME and/or FAILURE RECORDS data may aid in locating intermittent condition. If DTC cannot be duplicated, the information included in the FREEZE FRAME and/or FAILURE RECORDS can be useful in determining how many miles since the DTC set. It can also be used to determine how many ignition cycles the diagnostic reported a pass and/or fail condition. Operate vehicle within the same freeze frame conditions (RPM, load, vehicle speed, temperature, etc.) that were noted. This will isolate when the DTC failed. If other DTC(s) are set that share the same ground and/or 5-volt reference circuit, check for faulty connections or wiring.

If engine is allowed to sit overnight, ECT and IAT values should display within a degrees of each other. If temperature is not within 5°F (3°C), check for faulty ECT or IAT sensor.

If it is determined that DTC is intermittent, performing DTC P1114 or P1115 diagnostic may isolate the cause of the fault.

If ECT is greater than 140°F (60°C), this indicates that engine is capable of reaching the proper temperature, but not necessarily in the correct amount of time. This test must be repeated on a cold engine, engine coolant and intake air temperature at less than 122°F (50°C) and within 5°F (3°C) of each other. When starting a cold engine, engine should reach the specified temperature within 7 minutes. If specified temperature is not reached within the specified time, check coolant level, thermostat operation or if cooling fans are operating at all times.