1998 Q45 TPS replacement

[kpytoi9]

Hi,

I have a 98 Q45 with 135k miles on it. This morning I started it up and the Slip, ABS, and TCS lights were on and remained on. Did the diagnosis by pulling the codes and it’s the TPS Sensor. I wanted to know if anyone has details on how to replace the sensor.

[loystock]

Are you sure you need to replace the TPS? Which code number did you get when used the built-in diagnostic. Usually, the ABS-TCS-SLIP light illumination is due to faulty ABS Relay or one of the wheel sensors. Of course, other system components could be defective that's why you do the diagnostic.

All sorts of crazy things do happen when the alternator is failing. So better check you battery is good and the alternator charging voltage is steady and >13.8 VDC (spec is 14.1-14.7 VDC).

Below is the link to the TPS diagnostic and replacement procedure. Just make sure you verify the TPS is bad before replacing it.

http://www.nicoclub.com/FSM/Q45/1998_Q4 ... Q45/ec.pdf

[kpytoi9]

I took it to the dealer to get it diagnosed. They told me that there were 2 codes. One for the Throttle Position sensor and one for the control unit. Since the TPS is cheaper, i want to do that first to see if the problem goes away.

[loystock]

In most cases, dealer diagnostics are accurate since they have the more sophisticated test equipment. But looks like you would like to save some money. Besides, the Control Unit seldom fails. So I suggest that you take a 2nd opinion or do your own fault isolation using the built-in diagnostics. All you need is a jumper wire between the Data Link Connector (DLC) and chassis ground. The testing procedure and interpretation of results are straightforward.

Ensure that battery and alternator are Ok, then check the brake fluid level and ABS Actuator assembly. for any sign of leak.

Refer to the attached link below. Page BR-40 for Diagnostic info; BR-46 for Preliminary checks; BR-47 for Component Location; BR-48 for Schematic Diagram; BR60&61 and 70&71 for actual diagnostics; BR-62 for Malfunction Codes. There are lots of useful info from the FSM on how to approach your problem. You can save money if you can identify which component really needs replacement

http://www.nicoclub.com/FSM/Q45/1998_Q4 ... Q45/br.pdf