E014

ECM Code E014:

DFI Sensor Circuit:

DESCRIPTION:

The coolant sensor is a thermistor or variable resistor. The coolant sensor is a two wire sensor with a signal voltage coming from the ECM on Pin B, CKT 41OPC and a reference ground on Pin A, CKT 476PC.

As the temperature of the sensor increases, sensor resistance decreases. The signal voltage from the ECM to Pin A decreases as sensor temperature increases and current flows through the sensor element to Pin A, sensor ground.

Code EO14 "Shorted Coolant Sensor" sets because the ECM assumes that the coolant temperature can't be 142°C (287°F) or greater when the MAT sensor is 105°C or less (sensor signal shorted to ground).

TEST CONDITIONS:

1. Codes E037 and E038 clear.
2. MAT Sensor Value less than or equal to 105°C.

FAILURE CONDITIONS:

Coolant sensor value greater than or equal to 142°C. (sensor signal shorted to ground.)

ACTION TAKEN:

1. ECM turns on "SERVICE ENGINE SOON" telltale.
2. ECM commands BCM to display "SERVICE SOON" message on CCDIC.
3. ECM turns off both AIR solenoids.
4. ECM uses MAT sensor value in place of coolant sensor value for all calculations.

NOTES ON FAULT TREE:

1. With sensor shorted, parameter ED04 should read 142°C or greater. If not, then the sensor is not shorted, see NOTE ON INTERMITTENTS.

2. Checking for sensor shorted or CKT 410 shorted. If the parameter stays at 142° to 151° with the sensor unplugged, then the short is in CKT 410, between the sensor and ECM.

3. Fault is most likely at ECM connector or the ECM. Before ECM is replaced, perform "ECM Replacement Check", chart C-1.

NOTE ON INTERMITTENTS:

Manipulate CKT 410 wiring, the coolant sensor and ECM connector while observing ECM Parameter EDO4. If the failure is induced, the coolant temperature will jump from its normal value to the shorted reading of 142° to 151°C. Remove and replace both the COOLANT and ECM connectors and ensure that they are latched. If wiring and connector check out OK, substitute a known good coolant sensor and retest.
Review the snapshot data parameters stored with this code to verify failure condition. If the failure condition is verified, check and repair intermittent wiring connection, or sensor.