p1635 code
#1
Junior Member
Thread Starter
Join Date: Nov 2007
Location: kelso, washington
Posts: 6
Likes: 0
Received 0 Likes
on
0 Posts
p1635 code
Pulled this code on my 97 ssei bonneville. Does anyone know if this tends to be a pcm problem or a bad sensor causing the low voltage?
#2
-- SITE DONATOR --
True Car Nut
I would check the ground for the PCM, make sure it is clean and making good contact. Also check the wiring harness and ensure no wires have been pinched or cut, that could cause a short or low voltage situation. Otherwise that code does indicate an internal problem with the PCM.
#3
Senior Member
Posts like a Turbo
Join Date: Dec 2009
Location: Kitchener On.
Posts: 348
Likes: 0
Received 0 Likes
on
0 Posts
DTC P1635 5 Volt Reference Circuit
Refer to A/C Presure, Fuel Tank Pressure, TP, MAP, IAT, ECT Sensors .
<A href="http://127.0.0.1:9001/servlets/BlobShtml?ShtmlFile=47368&evc=sm&pubid=43&cellId=2 5084&mspsdsubkey=362#ss1-12485">Circuit Description
The PCM uses the 5 Volt Reference A circuit as a sensor feed to the following sensors:
<A href="http://127.0.0.1:9001/servlets/BlobShtml?ShtmlFile=47368&evc=sm&pubid=43&cellId=2 5084&mspsdsubkey=362#ss1-45501">Conditions for Setting the DTC
Important:
Be sure to inspect PCM and engine grounds for being secure and clean.
Check for the following conditions:
Refer to A/C Presure, Fuel Tank Pressure, TP, MAP, IAT, ECT Sensors .
<A href="http://127.0.0.1:9001/servlets/BlobShtml?ShtmlFile=47368&evc=sm&pubid=43&cellId=2 5084&mspsdsubkey=362#ss1-12485">Circuit Description
The PCM uses the 5 Volt Reference A circuit as a sensor feed to the following sensors:
- The TP sensor.
- The MAP sensor.
- The EGR Valve Pintle Position sensor.
<A href="http://127.0.0.1:9001/servlets/BlobShtml?ShtmlFile=47368&evc=sm&pubid=43&cellId=2 5084&mspsdsubkey=362#ss1-45501">Conditions for Setting the DTC
- The PCM detects a voltage out of tolerance condition on the 5 Volt Reference A circuit.
- The above condition is present for longer than 19 seconds.
- The PCM will illuminate the malfunction indicator lamp (MIL) during the second consecutive trip in which the diagnostic test has been run and failed.
- The PCM will store conditions which were present when the DTC set as Freeze Frame and Failure Records data.
- The PCM will turn OFF the MIL during the third consecutive trip in which the diagnostic has been run and passed.
- The History DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.
- The DTC can be cleared by using the scan tool.
Important:
Be sure to inspect PCM and engine grounds for being secure and clean.
Check for the following conditions:
- Poor connection at the PCM. Inspect harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and poor terminal to wire connection.
- Damaged harness. Inspect the wiring harness for damage.
- If the harness appears to be OK, observe the MAP display on the scan tool with the ignition ON, engine not running while moving connectors and wiring harnesses related to the following sensors. A change in the MAP display will indicate the location of the malfunction.
- The TP sensor.
- The MAP sensor.
- The EGR valve.
- The fuel tank pressure sensor (VIN K only).
#4
Retired Senior Admin
Expert Gearhead
Join Date: May 2006
Location: Sheboygan Wisconsin
Posts: 29,661
Likes: 0
Received 29 Likes
on
25 Posts
Keep in mind we have nearly every OBD code listed here. https://www.gmforum.com/showthread.p...84#post1391414
Thread
Thread Starter
Forum
Replies
Last Post