Coolant Temp Sensors Will Not Always Set A Code (ACU0401AP)

Publication date: 1995-03-01
Reference number: ACU0401AP

COOLANT TEMP SENSORS WILL NOT ALWAYS SET A CODE

TECHNICAL INFORMATION TIP

Reference Number(s): ACU0401AP, Date of Issue: March, 1995

COOLANT TEMPERATURE SENSORS

MODEL(S): 1986-95 Acura Legend

1987-88 Sterling 825

DATE OF ISSUE: March, 1995

ISSUE & TIP

A bad coolant temperature sensor will not always set a code in the ECU on early Acura Legend and Sterling 825 models. If the customer complains of a no-start after short trips and normal diagnostic procedures produce no results, try this:

Bring the engine to normal operating temperature before turning it off.
Set a DVOM on the high OHMS scale, then hook it to the green/white and red/white wires of the CTS. Make your connections at the EFI harness connectors on the right side of the engine compartment.
As the engine cools back down, keep an eye out for any opens in the DVOM readings.
An open in the CTS reading will be interpreted by the ECU as a very cold engine. The ECU will flood the engine with a long injector pulse width, causing the hard starting problems.

Courtesy of Import Service Magazine

with thanks to:

Jimmy Fulmer

Morgan's Garage

San Leon, Texas

REFERENCE NUMBER

ACU0401AP

NOTE: This information has been obtained from sources generally believed to be reliable. Use your own judgment before relying on this data. Neither the suppliers of these Technical Information Tips, nor lemon-25 Repair Information Company, LLC, guarantees or assumes responsibility for data accuracy or completeness, nor is liability assumed by the suppliers of these Technical Information Tips or lemon-25 Repair Information Company, LLC, for any claims or damages resulting from the use of this information.