Experiencing a no-start condition in your 1998 Toyota Camry can be incredibly frustrating. One potential clue when diagnosing this issue is discovering that your OBD2 port isn’t sending out data. This lack of communication can point towards a range of electrical problems that are preventing your engine from firing up. Let’s delve into how to troubleshoot this situation, drawing insights from a real-world scenario encountered with a similar Toyota vehicle.
When your car cranks but refuses to start, and you suspect a fuel delivery problem, checking for OBD2 communication is a smart diagnostic step. A missing signal from the OBD2 port can indicate a deeper electrical fault that might be cutting power to essential systems, including your fuel pump and potentially the engine control unit (ECU) itself.
One Toyota owner, working on a 1997 4Runner with a 5VZ engine, faced a similar “crank no start” situation. They correctly identified a lack of fuel delivery as a primary symptom. Here’s how their troubleshooting process, and the principles behind it, can guide you in diagnosing your 1998 Camry.
The first step is to confirm the fuel delivery issue. In the 4Runner case, the owner noted:
‘Cracked open the fuel line in the engine bay and it’s bone dry. There is fuel in the tank.
This simple test immediately points towards a problem in the fuel supply line, from the tank to the engine. If you’re comfortable working with fuel systems, carefully checking for fuel pressure at the fuel rail is a crucial initial check. Always prioritize safety when working with fuel systems.
Next, investigate the electrical supply to the fuel pump. The 4Runner owner proceeded to check for voltage at the fuel pump connector:
I tested for voltage at the blue-orange cable on the fuel pump connector, while cranking, and got nothing. Also unplugged what I believe is the COR, and tested for voltage at the blue-orange there while cranking, and got nothing.
This is a critical step. The fuel pump needs power to operate. The “blue-orange cable” likely refers to the power wire for the fuel pump in that specific Toyota model. The Circuit Opening Relay (COR) is a common component in Toyota fuel pump circuits. It’s designed to activate the fuel pump when the engine is cranking or running. No voltage at these points strongly suggests an electrical supply issue upstream of the fuel pump.
The owner also attempted to rule out a faulty camshaft position sensor, although this is less likely to directly cause a complete fuel pump failure, it’s still part of a comprehensive diagnostic approach:
I’m kind of a noob, but I set my multimeter to ohms and put one probe on each of the camshaft position sensor pins, it read 1.147. This seemed a little low according to the manual I have for a 99, but I got 1.160 on my running 4Runner so I think I can rule that out.
While sensor readings are important, in this no-start scenario with no fuel delivery, the focus should remain on the fuel pump circuit and related electrical components.
A quick way to further confirm a fuel delivery problem is to use starter fluid:
Spraying starter fluid while cranking gets the engine rumbling a bit.
This classic test bypasses the fuel system temporarily. If the engine briefly runs on starter fluid, it confirms that the ignition and compression systems are likely functional, and the problem is indeed fuel related.
The original poster then encountered a limitation when trying a common fuel pump test:
I read on another post here that with the diagnostic port in the engine bay I can jump the +B to Fp to test the pump and rule out some stuff, but my diagnostic port doesn’t have a pin in the Fp slot.
This is a valuable observation. On some older Toyotas, you can directly power the fuel pump by jumping the FP (Fuel Pump) pin to the +B (Battery positive) pin in the diagnostic connector. However, as seen in the image, not all diagnostic ports have the FP pin populated.
If your 1998 Camry’s OBD2 port isn’t sending data, this is a significant red flag. The OBD2 port relies on power and a functioning ECU. No data output suggests:
- Power Issues: The ECU and/or OBD2 port are not receiving power. This could be due to blown fuses, faulty relays, or wiring problems.
- ECU Malfunction: Less likely, but a failing ECU could also cause a lack of OBD2 communication.
- Wiring or Connector Problems: Issues with the wiring harness or connectors leading to the OBD2 port or ECU.
Troubleshooting Steps for “98 Camry OBD2 Port No Data” and No-Start:
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Check Fuses: Locate the fuse box(es) in your Camry (typically under the dash and in the engine bay). Inspect fuses related to the ECU, engine management, ignition, and OBD2/diagnostic systems. A blown fuse is a common cause of power loss.
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Inspect Relays: Similar to fuses, relays control power flow to various systems. Check relays related to the ECU and fuel pump. You can often swap identical relays to test, or use a multimeter to check relay function.
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Verify ECU Power and Ground: Use a wiring diagram for your 1998 Camry to identify the power and ground pins for the ECU. Use a multimeter to confirm that the ECU is receiving both power and ground. No power to the ECU will definitely cause a no-start and no OBD2 communication.
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OBD2 Port Power and Ground: Check for power and ground at the OBD2 port itself. Pin 16 is typically battery positive, and pins 4 and 5 are ground. No power here directly confirms a problem in the power supply to the diagnostic system.
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Wiring Inspection: Visually inspect the wiring harness around the ECU, OBD2 port, and fuse boxes for any signs of damage, corrosion, or loose connectors. Pay close attention to ground connections, as poor grounds are a common source of electrical problems.
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Battery Voltage: Ensure your battery is fully charged and in good condition. Low battery voltage can cause a multitude of electrical issues, including no-start and OBD2 problems. The 4Runner owner confirmed 12V at the +B terminal, which is a good starting point:
12V at +B
- Consider ECU Issues (Last Resort): If you’ve thoroughly checked power, grounds, fuses, relays, and wiring, and still have no OBD2 communication and a no-start, a faulty ECU becomes a possibility. However, this is less common, and all other electrical possibilities should be exhausted first. The 4Runner owner also considered this:
I tried with two different computers.
Trying a known good ECU is a valid troubleshooting step, but only after confirming all basic electrical supply issues.
Conclusion:
A “98 Camry Obd2 Port Not Sending Out Data” issue combined with a no-start condition points towards a significant electrical problem. By systematically checking fuses, relays, power and ground to the ECU and OBD2 port, and carefully inspecting wiring, you can effectively diagnose the root cause. Start with the basics – power supply – and methodically work through the system. Just like the 4Runner owner diligently investigated their fuel delivery problem, a step-by-step approach will help you get your Camry back on the road. And remember, taking your time and being methodical is key when tackling automotive electrical issues.
