I'm troubleshooting a DTC P0113 code on my 99 vette as it is preventing me from passing state emissions inspection. I'm up to step 10 in the diagnosis chart, in the manual. It states the following:

1. Turn OFF the ingnition.
2. Disconnect the PCM connector C2 located on the opposite side of the manufacturer's logo. Refer to PCM/TAC Module Replacement.
3. Inspect the IAT sensor ground circuit for an open. Refer to Testing for Continuity in Wiring Systems.

I have the cover off of the right wheel well and am looking at the PCM and see two connections. I can't seem to find the manufacturer's logo as described. So, I don't know which is the C2 connection. Both look alike. Is it the one on the outside or inside?

I saw something on the internet about a red connector (C1) and blue connector (C2), but I really don't know which one is the correct color for the C2. I pulled one and saw red inside. So, on a 1999 Coupe, is the red a C1 or C2 connection?

I'm at a standstill until I can determine the correct one to disconnect.

 

The wire colors at each pin number are different between the two connectors. Looks like C2 has this combination:



Connector Part Information • PCM Connector C2 Assembly 12191488
• TPA (RED) 12176410
• Connector Cover 12191108
Pin Wire Color Circuit No. Function
1 BLK/WHT 451 PCM Ground
(Automatic Transmission Only)
2 BRN 418 TCC Control Solenoid
(Automatic Transmission Only)
3 -- -- Not Used
4 PPL 421 AIR Solenoid Relay Control
5 TAN/BLK 464 Torque Delivered
6 RED/BLK 1228 Transmission Fluid Pressure Control Solenoid High
(Automatic Transmission Only)
7 -- -- Not Used
8 LT BLU/WHT 1229 Transmission Fluid Pressure Control Solenoid Low
(Automatic Transmission Only)
9 DK GRN/WHT 465 Fuel Pump Relay Control
10 WHT 121 Engine Speed (Tach) Output Signal
11-13 -- -- Not Used
14 RED/BLK 380 A/C Refrigerant Pressure Sensor Signal
15 RED 225 Alternator L Terminal
16 -- -- Not Used
17 DK GRN/WHT 762 A/C Request Signal (C60 only)
18 DK GRN 59 A/C Status Signal
19 -- -- Not Used
20 PPL 401 Vehicle Speed Sensor (VSS) Reference Low
21 YEL 400 Vehicle Speed Sensor (VSS) Signal
22-24 -- -- Not Used
25 TAN 472 IAT Sensor Signal
26 PPL 2121 Ignition Control 1
27 RED 2127 Ignition Control 7
28 LT BLU/WHT 2126 Ignition Control 6
29 DK GRN/WHT 2124 Ignition Control 4
30 -- -- Not Used
31 YEL 492 MAF Sensor Signal
32 LT GRN 432 MAP Sensor Signal
33 DK BLU 473 Engine Cooling Fan Relay 2 and 3 Control
34 DK GRN/WHT 428 EVAP Canister Purge Valve Control
35 -- -- Not Used
36 BRN 436 AIR Pump Relay Control
37-38 -- -- Not Used
39 RED 631 Camshaft Position Sensor B+ Supply
40 BLK/WHT 451 PCM Ground
41 -- -- Not Used
42 TAN/BLK 422 TCC Enable Circuit
(Automatic Transmission Only)
43 DK GRN/WHT 459 A/C Clutch Relay Control
44 LT GRN 1652 Reverse Inhibit Solenoid Control
45 WHT 1310 EVAP Canister Vent Valve Control
46 BRN/WHT 419 Malfunction Indicator Lamp (MIL) Control
47 WHT or YEL/BLK 375 or 1223 1 to 4 Up-shift Lamp Control or Transmission Shift Solenoid B
48 LT GRN 1222 Transmission Shift Solenoid A
49 -- -- Not Used
50 DK GRN/WHT 817 Vehicle Speed Output Circuit
51 YEL/BLK 1227 Transmission Temperature Sensor Signal
52 GRY 23 Alternator F Terminal
53 -- -- Not Used
54 DK BLU 1936 Fuel Level Sensor Signal
55-56 -- -- Not Used
57 PPL 719 IAT Sensor Ground
58 TAN/WHT 331 Engine Oil Pressure Sensor Signal
59 -- -- Not Used
60 BRN 2129 Ignition Control Reference Low Bank 1
61 BRN/WHT 2130 Ignition Control Reference Low Bank 2
62 GRY 773 PRND C Input Signal
(Automatic Transmission Only)
63 PNK 1224 Transmission Range Signal A
(Automatic Transmission Only)
64 DK GRN 890 Fuel Tank Pressure Sensor Signal
65 -- -- Not Used
66 PPL/WHT 2128 Ignition Control 8
67 RED/WHT 2122 Ignition Control 2
68 DK GRN 2125 Ignition Control 5
69 LT BLU 2123 Ignition Control 3
70-72 -- -- Not Used
73 LT BLU 1937 Fuel Level Sensor Signal (Secondary)
74-80 -- -- Not Used

 

Thanks! I found that. Now I'm not sure how to do the continuity test...Do I hook up an ohm meter to the IAT wire (which one), one wire to the IAT and ground the other wire from the ohm meter? Or do I use a light?

 

Disconnect battery !!!!!!

Get a continuity tester from your local auto parts store. It is a self powered tester with light bulb in it.

Hook to one end of the same wire and then hook to the other end. If bulb light up (good), if not you have a bad wire.

 

Thanks. I just decided to get the connector from Auto Zone. If it still acts up, then I'll change the IAT out.

 

All fixed! It turned out to be the IAT sensor. I replaced the connector anyway, just for good measure, since so many people have reported this to be a problem. Why wait for it to happen.