WHAT COULD CAUSE THE ENGINE TO STALL WHILE DRIVING - 2002 Toyota Prius

Recall ID # 06V266000 - ENGINE AND ENGINE COOLING -

Recall Date:JUL 19, 2006
Model Affected:2002 TOYOTA PRIUS

Summary:ON CERTAIN PASSENGER VEHICLES, DUE TO IMPROPER MOLDING OF THE RESIN BODY OF THE CRANKSHAFT POSITION SENOR INSTALLED ON THE ENGINE BLOCK, ENGINE OIL MAY PENETRATE THE SEAL AND ENTER THE SENSOR WIRING CONNECTOR. THE WIRE HARNESS CONNECTOR MAY NOT BE SUFFICIENTLY ATTACHED TO THE LOCKING TAB OF THE SENSOR WIRING CONNECTOR.

Consequence:ENGINE OIL INSIDE THE SENSOR WIRING CONNECTOR COULD CAUSE EXPANSION DUE TO THE HEAT OF THE ENGINE AND COULD DEFORM THE SENSOR WIRING CONNECTOR. THE CONNECTOR MAY BECOME DISCONNECTED, WHICH COULD CAUSE THE ENGINE TO STALL WHILE DRIVING AND NOT BE ABLE TO BE RESTARTED INCREASING THE RISK OF A CRASH.

Remedy:DEALERS WILL REPLACE THE CRANKSHAFT POSITION SENSOR FREE OF CHARGE. THE RECALL BEGAN ON JULY 26, 2006. OWNERS MAY CONTACT TOYOTA AT 1-800-331-4331.
Potential Units Affected:34771
Notes:TOYOTA MOTOR NORTH AMERICA, INC. 60G

Air Conditioning pressure cycling switch

Question:

I have a 1994 Chevy truck and I need to recharge the air conditioning. When i hook up the can of R134a Freon the compressor does not engage to suck in the freon. Could it be a bad Air Conditioning Pressure Cycling Switch?

Answer:

The situation you are running into is normal. The compressor will not engage until there is enough pressure seen at the air conditioning low pressure cycling switch. So what you will need to do is manually bypass the switch with a jumper wire. This will engage the compressor and allow it to suck in the freon. After you have installed one can (14 oz.), then remove the jumper wire and finish the recharge cycle with the pressure cycling switch plugged in.

How to Recharge Air Conditioning

Chevy Code 42

Had a customer bring in a 1989 Chevy Van G20, 5.7L with a stumble issue and intermittent stall. The check engine light was on .The check engine light codes can be Extracted without a scan tool. The code that was extracted was Code 42 : Electronic spark timing (EST) circuit fault.

A quick read of a great article on Code 42 that covers the specific components involved : The EST system consists of the ignition module, computer (ECM/PCM), and the connecting wiring.

Used a Multi-meter to test and check the wiring and found no issues, but what was noticed is the fuel injectors would click several times by themselves with the key off. This was a bit strange, but lead me to believe there had to be a short somewhere causing this and sure enough there was an internal short in the ECM. Purchased an ECM for the local parts house for just under $100.00 and replaced it. The engine no longer has the stumble and it no longer puffs smoke when you start it up (originally thought to be valve seals gone bad).

Customer happy!

Side note* I did try a new EST first as it was easy to get to and a quick test. It is located under the drivers seat along with the ECM.

Check Engine Light On, What Do I do ?

When the Check Engine Light comes on and keeps a steady light the computer is letting you know there is an issue with one of the sensors or sensor readings. When the Check Engine Light is flashing the computer is letting you know that something serious is wrong and the vehicle should not be driven more than a mile and then towed to prevent irreversible damage.

On vehicles that are 1996 and newer, It requires the use of a Scan Tool to extract the check engine light codes. Once you have the code you can look out the code definition and determine the best course of action for the issue. Once the repairs are completed you will need to clear the codes out of the computers memory with the Scan Tool.

Gas Mileage Lower than Normal?

Today’s engine management systems rely on many different sensor inputs to regulate fuel economy, performance and emissions.

Symptom: Poor Fuel Economy

Probable Causes: Fuel Rich Codes (P0172 and/or P0175)

With the price of gasoline, you don’t want to ignore this kind of problem for long. When fuel economy is down, you may find any number of codes:
• P0172 and/or P0175 are rich codes, and indicate a general rich air/fuel condition. The underlying cause may be anything that increases fuel delivery, such as excessive fuel pressure, a defective fuel pressure regulator, plugged return line, or leaky injectors. Decreased airflow from a dirty air filter or restricted air intake misleads the mass airflow sensor or engine management system into believing the engine is using more air or is under more load than actual.

Code P0720, P0731, P1790,P0700

Customer Problem:

I have a 1999 Chrysler 300M with a 3.5L engine. My Check Engine light came on and at the same time I lost my dash gauges and it will not shift out of first gear.

Solution:

Computer Diagnostics done to extract the codes for the check engine light. The coeds were:

P0720 = Output shaft speed sensor error

P0731 = First gear incorrect ratio

P1790 = Fault immediately after shift

P0700 = Transmission fault code

Since this situation all happened at once it would make sense that they are related. After removing and testing the Output shaft sensor that is supposed to be at 800 ohms, and was showing completely open, the Output shaft sensor was proven to have failed. Replaced the Output Shaft Sensor ( $20.00 ) and cleared the codes. Test drove the vehicle and all is working normal. Customer happy.

Electronic Engine Controls and Sensors | Testing Procedures

All Sequential Fuel Injection (SFI) systems use the EEC system. The heart of the EEC system is a microprocessor called the Powertrain Control Module (PCM). The PCM receives data from a number of sensors and other electronic components (switches, relays, etc.). Based on information received and information programmed in the PCM's memory, it generates output signals to control various relays, solenoids and other actuators. The PCM in the EEC system has calibration modules located inside the assembly that contain calibration specifications for optimizing emissions, fuel economy and driveability. The calibration module is called a PROM.

Electronic Engine Controls and Sensor Testing Procedures
Powertrain Control Module (PCM)
Throttle Position (TP) sensor
Mass Air Flow (MAF) sensor Intake Air Temperature (IAT) sensor
Idle Air Control (IAC) valve
Engine Coolant Temperature (ECT) sensor
Heated Oxygen Sensor (HO2S)
Camshaft Position (CMP) sensor
Knock Sensor (KS)
Vehicle Speed Sensor (VSS)
Crankshaft Position (CKP) sensor