Engine Controls - Revised Codes E041 and E059
89cadillac02Bulletin No.: T-89-62
File in Group: 8
Number: 94 Corp. Ref No.: 816533
Date: Jan. 1989
SUBJECT: ECM TROUBLE CODE DIAGNOSIS FOR CODES E041 AND E059
MODELS AFFECTED: 1988-1989 DE VILLES AND FLEETWOODS 1987-1988 ALLANTES
This bulletin provides updated information for the facing page and diagnostic chart for ECM Trouble Code Diagnosis for Allante Code E041, and DeVille and Fleetwood Code E059.
Attached you will find copies of the facing pages and diagnostic charts which can be inserted into your Service Information Manual.
FIGURE 8D1-62 - PFI HEI CIRCUIT:
CODE E041
NO CAM SENSOR SIGNAL
FIGURE 8D1-63 - ECM CODE E041:
TEST CONDITIONS: 1. Code E012 not set; 2. Distributor Reference pulses being received; 3. RPM < or = to 1600
FAILURE CONDITIONS: No cam reference pulses being received for 5 seconds.
ACTION TAKEN: ECM turns on "Engine Control System Fault" telltale.
DESCRIPTION: The cam sensor is located on the distributor shaft and provides one pulse per rotation of the distributor. The ECM uses the cam sensor signal to know the location of the camshaft for proper fuel distribution. Code E041 sets when the ECM knows the engine is turning (reference pulses being received on CKT 430) and does not detect any cam sensor pulses.
Notes On Fault Tree:
1. This trouble tree requires the use of five jumper wires which can be fabricated using terminal P/N 1201483 and 12014837. When checking voltage on cam sensor circuit, a typical good voltage is between 0.5 and 3.5 volts and varying.
NOTES ON INTERMITTENTS:
Manipulate affected wiring while the engine is running. If the fault is induced the code will set and the wiring should be repaired for an intermittent open or short to ground.
Disconnect and reconnect the distributor connector and ECM connector and ensure they are latched.
FIGURE 8D1-74 - DFI SENSOR CIRCUIT:
FIGURE 8D1-75 - ECM CODE E59:
ECM CODE E59, TRANSMISSION TEMPERATURE SENSOR CIRCUIT
TEST CONDITIONS: Always tested.
FAILURE CONDITIONS: Transmission temperature greater than or equal to 151~C or transmission temperature less than or equal to -40~C.
ACTION TAKEN: 1. VCC is engaged at a higher than normal vehicle speed.
Description:
The transmission temperature sensor is a two wire sensor that provides the temperature of the transmission oil as it enters the transmission oil cooler. The transmission temperature sensor receives a voltage signal from the ECM on CKT 520. As the temperature of the transmission oil increases, the sensor resistance decreases, and the signal voltage on CKT 520 increases. The ECM interprets low voltage as a low temperature and a high voltage as a high temperature. The transmission temperature sensor is a thermistor (like the Coolant Temp Sensor). The ECM uses the transmission temperature input to delay VCC engagement in cases of very high transmission oil temperature.
Code E59 is designed to detect a transmission temperature sensor open or shorted. Code E59 will not set due to transmission overheating or very cold ambient conditions.
Note On Fault Tree:
1. The transmission temp sensor CKT 520 is shorted to ground.
2. CKT 520 is open to the sensor or the sensor is open to ground.
Note On Intermittents:
Manipulate the transmission temperature sensor and ECM connector and the CKT 520 wiring while observing parameter P.1.5. Remove and replace the transmission temperature sensor and ECM connectors and ensure that they are latched. If the wiring and connectors check out OK, substitute a known good transmission temperature sensor and retest. Review the snapshot data parameters stored with the code to verify failure condition. Refer to section 6E-B "Symptoms" for complete details on using the "Snapshot on code set" feature. If the failure condition is verified, check and repair intermittent wiring connection or sensor.