Last year my wife’s 1995 Dodge Stratus didn’t start when she tried to come home from work. I looked at it and she didn’t have spark or fuel. Figured it was the crank sensor so I replaced it and everything seemed fine. Then the A/C stopped working and the car started to die intermittently. Sometimes it would die while she’s at a light sometimes it would die driving down the road sometimes it would die just idling. I checked the check engine light codes and got back code 71, code 33 twice, and code 23.
-Code 71 is PCM output voltage low.
-Code 33 is Air conditioning clutch relay circuit. An open or shorted condition detected in the compressor clutch relay circuit.
-Code 23 is Intake air temperature sensor voltage out of normal range.
After months with no success tinkering, I decided just to buy the engine control module. I put the new module in and the codes went away. The car was running fine, A/C and all, until a couple of days ago. The car is not dying intermittently like it was but the A/C is out and the CEL has the same codes: code 71 code 33 twice and code 23. I also observed the occasionally while checking codes the CEL will stay solid and the cruise light will come on and stay solid then CEL codes would start flashing from the beginning. Please help!
RESPONSE
I would start with one code and see if you can take care of it one at a time. The only thing in common with all three codes other than the PCM would be the wiring and or connection. This vehicle is quite old and the wiring harness would be as well. The Air Conditioning may just be a sticking relay.
Lets start with the IAT – Intake Air Temperature sensor.
Code 23 Intake Air Temperature (IAT) Sensor Operation
The Intake Air Temperature (IAT) sensor measures the temperature of the intake air as it enters the engine. The sensor supplies one of the inputs the PCM uses to determine injector pulse width and spark advance. As the intake air temperature varies, the IAT sensor’s resistance changes, resulting in a different input voltage to the PCM.
On all vehicles except 1996–98 models with the 2.0L SOHC engine, the IAT sensor threads into the intake manifold. On 1996–98 vehicles equipped with a 2.0L SOHC engine, the IAT and Manifold Absolute Pressure (MAP) sensors are combined into a single sensor which is attached to the intake manifold.
Code 23 Testing Intake Air Temperature (IAT) sensor
- Visually check the connector, making sure it is attached properly and all of the terminals are straight, tight and free of corrosion.
- With the ignition key OFF, detach the wire harness connector from the IAT sensor.
- Connect a digital ohmmeter (DVOM) to the sensor terminals. The ohmmeter should read as follows:
- With the engine and sensor at normal operating temperature, about 200°F, the DVOM should read about 700–1,000 ohms.
- With the engine and sensor at room temperature, about 70°F, the DVOM should read about 7,000–13,000 ohms.