MIL ON - DTC's 27 and 19 Diagnosis/Repair
Group: ENGINE ELECTRICALNumber: 93-36-012
Date: SEPTEMBER 1993
Model: 1993 SCOUPE
Subject:
KNOCK SENSOR CODES 27 AND 19
The following diagnosis and repair procedures should be used to repair 1993 Scoupes if the check engine light illuminates and Knock Sensor codes 27 and or 19 have been stored.
CONDITION: CODE 27
Two codes may be stored, Code 27 and 33. If a Code 33 (A/C compressor) is stored in addition to a Code 27, perform the Code 27 repair as outlined below. After that repair has been performed, clear all codes and check for any additional codes. Code 33 should not reappear.
DIAGNOSIS
1. With the engine at operating temperature, unplug the Knock Sensor Connector (C13). Using a digital volt ohm meter (DVOM), check for 4.75 - 5.0 M ohms resistance between pins 1 and 2 on the sensor side. If the sensor is not within specification, loosen the sensor and re-torque to 12-14 ft.lbs. with the engine at operating temperature. Recheck the resistance. If the sensor is still not within specification, replace the sensor.
NOTE:
Correct knock sensor torquing is critical to its proper operation.
2. If the sensor is within specifications, reconnect the knock sensor and remove the ECM connector (COl). Check resistance between pins 11 and 30 on the harness side of C01. If resistance is not within specification, repair or replace the wiring.
To check individual wires, Check ECM pin 11 to knock sensor harness side pin 2. Also check ECM Pin 30 to knock sensor side pin 1. If either wire has resistance, repair the wire.
CONDITION: Diagnosis Trouble Code 19
This code reveals an internal ECM (Electronic Control Module) circuit condition. Replacement of the ECM is necessary.